JP3248006U - Laser phosphor integrated light source - Google Patents

Abstract

A compact, bright and efficient laser phosphor integrated light source is provided. The laser-based light source includes a material (2) disposed adjacent to a laser diode chip (1) on a package base, and an optical element coupled to the material. The optical element is aligned to receive electromagnetic radiation from the laser diode chip. The optical element includes a wavelength conversion material (4) and is configured to at least partially receive electromagnetic radiation emitted from the laser diode chip. The optical element is surrounded on its sides by a reflective material (5). [Selected Figure]

Description

Light-emitting diodes (LEDs) are rapidly becoming a popular lighting technology due to the high efficiency, long life, low cost, and non-toxicity of this solid-state lighting technology. LEDs are two-lead semiconductor light sources, typically based on a p-i-n junction diode, that emit electromagnetic radiation when activated. Light emitted from an LED is spontaneous and typically follows a Lambertian pattern. When an appropriate voltage is applied to the leads, electrons and holes recombine within the device, releasing energy in the form of photons. This effect is called electroluminescence, and the color of the light emitted is determined by the gap in the energy bands of the semiconductor.

By combining GaN-based LEDs with wavelength conversion materials such as phosphors, solid-state white light sources have been realized. This technology of using GaN-based LEDs and fluorescent materials to obtain white light offers many advantages over incandescent light sources, including lower power consumption, longer life, improved physical robustness, smaller size, and faster switching speeds, and currently illuminates the world around us. Light-emitting diodes are currently used in a variety of applications, including aviation lighting, automotive headlamps, advertising, general lighting, traffic signals, and camera flashes. LEDs enable the development of new text and video displays and sensors, and their high switching rates are extremely useful for advanced communication technologies.

Although useful, LEDs still suffer from limitations which the invention disclosed below hopes to overcome.

The present invention provides an integrated white electromagnetic radiation source device and method using a combination of a gallium-nitrogen-containing material-based laser diode pump source and a phosphor-based emission source. In the present invention, a gallium- and nitrogen-based violet, blue, or other wavelength laser diode source is tightly integrated with a phosphor, such as a yellow phosphor, to form a compact, bright, and efficient white light source. By way of example, the source can be used for general or specialized applications.

In one embodiment, the laser-based light source includes a package base, a laser diode chip coupled to the package base, the laser diode chip configured to output a laser beam of electromagnetic radiation from an output surface, the laser diode chip configured to output electromagnetic radiation at a first wavelength, a material having a reflective surface coupled to the package base and positioned adjacent to the laser diode chip on the package base, and an optical element directly bonded to a top surface of the material, a groove extending between the material and the optical element, the groove extending between the material and the optical element and the laser diode chip, the laser diode chip being aligned with the laser diode chip. The optical element includes an optical element including a wavelength conversion material configured to convert at least a portion of the electromagnetic radiation in the laser light having a first wavelength to a second wavelength longer than the first wavelength, and a reflector surrounding a side surface of the optical element, the reflector being configured to reflect a portion of the electromagnetic radiation incident on the side surface of the optical element configured to emit light from a top surface including a first portion having the first wavelength and a second portion having a second wavelength.

In one embodiment, the laser-based light source further comprises one or more additional laser diode chips and one or more additional grooves, each of the one or more additional laser diode chips aligned with one of the additional grooves, and the one or more additional laser diode chips configured to emit electromagnetic radiation at the first wavelength.

In another embodiment, the laser-based light source further comprises one or more additional laser diode chips and one or more additional grooves, each of the one or more additional laser diode chips aligned with one of the additional grooves, and at least one of the one or more additional laser diode chips configured to emit electromagnetic radiation at a second wavelength different from the first wavelength.

In another embodiment, the groove is formed in the top of the material and extends from a side of the material to reflect at least a portion of the electromagnetic radiation upwardly toward the optical element.

In another embodiment, the material is thermally conductive and includes silicon (S), silicon carbide (SiC), germanium (Ge), gallium arsenide (GaAs), sapphire, ceramic aluminum nitride (AlN), ceramic aluminum oxide (Al2O3), ceramic boron nitride (BN), aluminum (Al), or copper (Cu), and the reflective surface has a reflective coating on the material.

In another embodiment, the wavelength converting material is diffused throughout the optical element.

In another embodiment, the upper portion of the optical element has an optical homogenizer that improves the color uniformity of the light emitted from the top surface of the optical element.

In another embodiment, at least one of the sides, top, or bottom of the groove is covered with a reflective coating.

In another embodiment, a gap extends between at least some sides of the optical element and the reflector.

In another embodiment, the laser-based light source includes a dispersing material in the groove, the dispersing material in the groove configured to at least partially disperse electromagnetic radiation from the laser diode chip into the optical element.

In another embodiment, the groove has flat sidewalls or curved sidewalls.

In another embodiment, the reflector has a reflective coating on the inner wall of the reflector.

In yet another embodiment, the optical element includes at least one of a dispersive feature, a diffractive feature, or a photonic crystal structure that provides color uniformity of light emitted from the top surface of the optical element.

Another embodiment is a surface mounted device (SMD) that includes the laser-based light source described above.

In another embodiment, a laser-based light source includes a package base, a laser diode chip coupled to the package base, the laser diode chip configured to output a laser beam of electromagnetic radiation from an output surface, the laser diode chip configured to output electromagnetic radiation at a first wavelength, a material having a reflective surface coupled to the package base and positioned adjacent the laser diode chip on the package base, an optical element coupled directly to a top surface of the material, and a light guide having one end aligned with the output surface of the laser diode chip and another end aligned with the optical element, the light guide being configured to guide the laser beam of electromagnetic radiation from the laser diode chip. The optical element includes a light guide configured to at least partially guide electromagnetic radiation to the optical element, the optical element including a wavelength conversion material configured to at least partially receive the electromagnetic radiation emitted to the optical element, the wavelength conversion material configured to convert at least a portion of the electromagnetic radiation in a laser beam having a first wavelength to a second wavelength longer than the first wavelength, and a reflector surrounding a side surface of the optical element, the reflector being configured to reflect a portion of the electromagnetic radiation incident on the side surface of the optical element configured to emit light from a top surface including a first portion having the first wavelength and a second portion having a second wavelength.

In one embodiment, the laser-based light source further comprises a groove extending between a portion of the material 2 and a portion of the optical element, a second laser diode chip, and a second light guide, the light guide aligned with a first end of the groove and the second light guide aligned with a second end of the groove, the second light guide configured and arranged to guide second electromagnetic radiation from the second laser diode chip into the groove in the optically transparent material 2.

In another embodiment, the laser-based light source includes a groove extending between a portion of the material and a portion of the optical element, and a dispersing material disposed in the groove, the dispersing material in the groove configured to disperse electromagnetic radiation from the laser diode chip to the optical element.

A further understanding of the nature and advantages of the present invention may be realized by reference to the latter portions of the specification and the accompanying drawings.

FIG. 1A is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to some embodiments of the present invention. FIG. 1B is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to some embodiments of the present invention. FIG. 1C is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to some embodiments of the present invention. FIG. 1D is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to some embodiments of the present invention.

FIG. 2 is a simplified top view of a phosphor-integrated laser-based light source according to one embodiment of the present invention shown in FIGS. 1A-1D.

FIG. 3 is a simplified perspective view of a phosphor-integrated laser-based light source according to another embodiment of the present invention.

FIG. 4 is a simplified cross-sectional perspective view of the phosphor-integrated laser-based light source according to one embodiment of the present invention shown in FIG.

FIG. 5 is a simplified perspective view of a blank having grooves formed on its upper surface in accordance with one embodiment of the present invention.

FIG. 6 is a simplified perspective view of a blank having grooves formed on its upper surface in accordance with another embodiment of the present invention.

FIG. 7A is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. FIG. 7B is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. FIG. 7C is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. FIG. 7D is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. FIG. 7E is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. FIG. 7F is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention.

FIG. 8A is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. FIG. 8B is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention.

FIG. 9A is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to another embodiment of the present invention. FIG. 9B is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to another embodiment of the present invention. FIG. 9C is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to another embodiment of the present invention.

FIG. 10A is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to another embodiment of the present invention. FIG. 10B is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to another embodiment of the present invention. FIG. 10C is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to another embodiment of the present invention.

FIG. 11A is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to another embodiment of the present invention. FIG. 11B is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to another embodiment of the present invention.

FIG. 12A is a simplified bottom view of the light guides and grooves of the phosphor-integrated laser-based light source according to one embodiment of the present invention shown in FIGS. 11A-11B. FIG. 12B is a simplified bottom view of the light guides and grooves of the phosphor-integrated laser-based light source according to one embodiment of the present invention shown in FIGS. 11A-11B.

FIG. 13 is a simplified diagram illustrating a light guiding structure according to one embodiment of the present invention.

FIG. 14A is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. FIG. 14B is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. FIG. 14C is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. FIG. 14D is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. FIG. 14E is a simplified diagram illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention.

FIG. 15A is a simplified diagram illustrating a process for forming a groove at the bottom of an optically transparent material according to one embodiment of the present invention. FIG. 15B is a simplified diagram illustrating a process for forming a groove at the bottom of an optically transparent material according to one embodiment of the present invention.

FIG. 16 is a simplified diagram showing a metallization pattern on the bottom of an optically transparent material according to one embodiment of the present invention.

FIG. 17A is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to another embodiment of the present invention. FIG. 17B is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to another embodiment of the present invention.

FIG. 18A is a simplified bottom view of the light guides and grooves of a phosphor-integrated laser-based light source according to one embodiment of the present invention shown in FIGS. 11A-11B. FIG. 18B is a simplified bottom view of the light guides and grooves of the phosphor-integrated laser-based light source according to one embodiment of the present invention shown in FIGS. 11A-11B.

FIG. 19 is a simplified cross-sectional view of a phosphor-integrated laser-based light source package according to some embodiments of the present invention. FIG. 20 is a simplified cross-sectional view of a phosphor-integrated laser-based light source package according to some embodiments of the present invention. FIG. 21 is a simplified cross-sectional view of a phosphor-integrated laser-based light source package according to some embodiments of the present invention.

FIG. 22A is a simplified perspective view of a phosphor-integrated laser-based light source package according to another embodiment of the present invention. FIG. 22B is a simplified perspective view of a phosphor-integrated laser-based light source package according to another embodiment of the present invention.

FIG. 23A is a simplified cross-sectional view of a laser-based light source according to some embodiments of the present invention. FIG. 23B is a simplified top view of a laser-based light source according to some embodiments of the present invention.

FIG. 24A is a simplified cross-sectional view of optical elements that can be used in phosphor-integrated laser-based light sources according to some embodiments of the present invention. FIG. 24B is a simplified cross-sectional view of optical elements that can be used in phosphor-integrated laser-based light sources according to some embodiments of the present invention. FIG. 24C is a simplified cross-sectional view of optical elements that can be used in phosphor-integrated laser-based light sources according to some embodiments of the present invention. FIG. 24D is a simplified cross-sectional view of optical elements that can be used in phosphor-integrated laser-based light sources according to some embodiments of the present invention.

FIG. 25A is a simplified cross-sectional view of a laser-based light source according to some embodiments of the present invention. FIG. 25B is a simplified partial cutaway view of a laser-based light source according to some embodiments of the present invention.

FIG. 26A is a simplified cross-sectional view of a laser-based light source according to some embodiments of the present invention. FIG. 26B is a simplified partial cutaway view of a laser-based light source according to some embodiments of the present invention.

FIG. 27A is a simplified cross-sectional view of a laser-based light source according to some embodiments of the present invention. FIG. 27B is a simplified partial cutaway view of a laser-based light source according to some embodiments of the present invention.

FIG. 28A is a simplified cross-sectional view of a laser-based light source according to some embodiments of the present invention. FIG. 28B is a simplified top view of a laser-based light source according to some embodiments of the present invention.

FIG. 29A is a simplified cross-sectional view of a laser-based light source according to some embodiments of the present invention. FIG. 29B is a simplified partial cutaway view of a laser-based light source according to some embodiments of the present invention. FIG. 29C is a simplified partial cutaway view of a laser-based light source according to some embodiments of the present invention.

FIG. 30A is a simplified cross-sectional view of a laser-based light source according to some embodiments of the present invention. FIG. 30B is a simplified top view of a laser-based light source according to some embodiments of the present invention.

FIG. 31A is a simplified cutaway view of a laser-based light source according to some embodiments of the present invention. FIG. 31B is a simplified cutaway view of a laser-based light source according to some embodiments of the present invention.

FIG. 32A is a simplified cross-sectional view of a laser-based light source according to some embodiments of the present invention. FIG. 32B is a simplified perspective view of a laser-based light source according to some embodiments of the present invention. FIG. 32C is a simplified partial cutaway view of a laser-based light source according to some embodiments of the present invention.

FIG. 33A is a simplified cross-sectional view of a laser-based light source according to some embodiments of the present invention. FIG. 33B is a simplified plan view of a laser-based light source according to some embodiments of the present invention.

FIG. 34A is a simplified cross-sectional view of a laser-based light source and components according to some embodiments of the present invention. FIG. 34B is a simplified partial cutaway view of a laser-based light source and components according to some embodiments of the present invention. FIG. 34C is a simplified partial cutaway view of a laser-based light source and components according to some embodiments of the present invention. FIG. 34D is a simplified partial cutaway view of a laser-based light source and components according to some embodiments of the present invention.

FIG. 35A is a simplified perspective view of a laser-based light source according to some embodiments of the present invention. FIG. 35B is a simplified cutaway view of a laser-based light source according to some embodiments of the present invention.

FIG. 36A is a simplified perspective view of a laser-based light source according to some embodiments of the present invention. FIG. 36B is a simplified cutaway view of a laser-based light source according to some embodiments of the present invention.

FIG. 37A is a simplified perspective view of a laser-based light source and various component structures according to some embodiments of the present invention. FIG. 37 is a simplified perspective view of a laser-based light source and various component structures according to some embodiments of the present invention. FIG. 37 is a simplified perspective view of a laser-based light source and various component structures according to some embodiments of the present invention.

FIG. 38A is a simplified perspective view of a laser-based light source and various component structures according to some embodiments of the present invention. FIG. 38 is a simplified perspective view of a laser-based light source and various component structures according to some embodiments of the present invention. FIG. 38 is a simplified perspective view of a laser-based light source and various component structures according to some embodiments of the present invention.

FIG. 39A is a simplified perspective view of components of a laser-based light source according to some embodiments of the present invention. FIG. 39B is a simplified perspective view of components of a laser-based light source according to some embodiments of the present invention. FIG. 39C is a simplified perspective view of components of a laser-based light source according to some embodiments of the present invention.

FIG. 40A is a simplified perspective view of components of a laser-based light source according to some embodiments of the present invention. FIG. 40B is a simplified perspective view of components of a laser-based light source according to some embodiments of the present invention. FIG. 40C is a simplified perspective view of components of a laser-based light source according to some embodiments of the present invention.

FIG. 41 is a simplified perspective view of components of a phosphor-integrated laser-based light source according to one embodiment of the present invention.

FIG. 42A is a simplified perspective view showing parts of the components of a laser-based light source according to some embodiments of the present invention. FIG. 42B is a simplified perspective view showing parts of components of a laser-based light source according to some embodiments of the present invention.

FIG. 43A is a simplified perspective view showing parts of the components of a laser-based light source according to some embodiments of the present invention. FIG. 43B is a simplified perspective view showing parts of components of a laser-based light source according to some embodiments of the present invention.

FIG. 44 is a simplified perspective view of components of a phosphor-integrated laser-based light source according to one embodiment of the present invention.

FIG. 45A is a simplified perspective view showing parts of the components of a laser-based light source according to some embodiments of the present invention. FIG. 45B is a simplified perspective view showing parts of components of a laser-based light source according to some embodiments of the present invention.

FIG. 46 includes simplified perspective and exploded views of components of a laser-based light source according to one embodiment of the present invention.

Detailed Description

The present invention provides an integrated white electromagnetic radiation source device and method using a combination of a gallium-nitrogen-containing material-based laser diode pump source and a phosphor-based emission source. In the present invention, a gallium- and nitrogen-based violet, blue, or other wavelength laser diode source is tightly integrated with the phosphor to form a compact, high brightness, and highly efficient white light source.

The present invention provides further advantages over existing technology. In particular, the present invention enables a cost-effective white light source. In specific embodiments, the optical devices of the present invention can be manufactured in a relatively simple and cost-effective manner. In some embodiments, the apparatus and methods can be manufactured using conventional materials and/or methods by those skilled in the art. In some embodiments of the present invention, the gallium-nitrogen containing laser diode source is based on c-plane gallium nitride material, while in other embodiments, the laser diode is based on non-polar or semi-polar gallium and nitride material. In one embodiment, the white light source is comprised of a chip-on-submount (CoS) with phosphor integrated on the submount to form a chip and phosphor on submount (CPoS) white light source.

In various embodiments, the laser device and the phosphor device are mounted on a common support member with or without an intermediate submount, and the phosphor material operates in a transmission or reflection mode to function as a white light emitting laser based light source. By way of example only, the present invention may be applied to applications such as white light illumination, white spotlights, flashlights, motor vehicle headlights, lighting for all terrain vehicles, light sources used in recreational sports such as biking, surfing, running, racing, boating, light sources used in drones, aircraft, robots and other mobile and robotic applications, security and defense applications, multi-color lighting, flat panel lighting, medical, metrology, beam projection and other displays, high intensity lamps, spectroscopy, entertainment, theater, music, concerts, fraud detection analysis and/or authentication, tools, water treatment, laser blinding, targeting, conversion, transportation, leveling, curing and other chemical processes, heating, cutting and/or ablation, pumping for other optical devices, other optoelectronic devices and related applications, and light source illumination.

FIG. 1A is a simplified cross-sectional view of a phosphor-integrated laser-based light source according to one embodiment of the present invention. The light source includes a laser diode chip 1 disposed in a package base with a face arranged to emit light into a cavity or groove formed in the top surface of material 2 and/or the bottom surface of optically transparent material 3. Alternatively, light may be directly directed into optically transparent material 3. Laser diode chip 1 may include one or more laser diodes, and the light may be laser light having a wavelength, for example, in the blue or other color region. Light may be directly incident from laser diode chip 1 or may be incident via a light guide.

In some embodiments, the package base may be a printed circuit board (PCB). In other embodiments, the package base may be the bottom of a semiconductor package configured to conduct heat from the laser diode chip 1 and material 2 to an underlying structure such as solder, a metal core PCB, a heat sink, etc. The package base may also include a metal slug (e.g., Cu or Al), plated other metals, or a composite of metal and ceramic material (e.g., _AlN , _Al2O3 ). In yet another embodiment, the package base may be a slab of metal (e.g., Cu or Al) forming part of a metal core PCB such as a chip on board (COB).

In embodiments where the laser diode chip 1 emits light towards the groove, the groove may form an air gap between the material 2 and the optically transparent material 3. The top surface of the material 2 and/or the inside of the groove may be covered with a reflective coating to direct and/or reflect the light upwards. The reflective coating may be, for example, silver (Ag) or aluminium (Al), and the reflective coating may be deposited as a flat specular film if the surface is smooth, or as a diffusely reflective rough film if the surface is uneven.

Material 2 at least partially directs and/or reflects light from the laser diode chip 1 upwards towards the optically transparent material 3. Material 2 may have high thermal conductivity to conduct heat from the optically transparent material 3 and/or the wavelength conversion material 4 to the package base. In some embodiments, material 2 may include silicon (S), silicon carbide (SiC), germanium (Ge), gallium arsenide (GaAs), sapphire, ceramic aluminum nitride (AlN), ceramic aluminum oxide (Al2O3), ceramic boron nitride (BN), aluminum (Al), copper (Cu), or other thermally conductive materials.

If material 2 is Si, the grooves can be formed by KOH etching to create angled sidewalls. A wide variety of groove shapes are possible. FIG. 6 illustrates a groove with a narrow neck that opens into a polygonal shape. In some embodiments, optically transparent material 3 may have a similar shape to the groove. For example, FIG. 6 illustrates the outline of optically transparent material 3 with a polygonal shape similar to the groove. In some embodiments, the grooves may be partially or completely filled with diffuse volume scatterers (e.g., _TiO2 or _Al2O3 particles in a low refractive index matrix such as glass, epoxy, or _silicone ).

The optically transparent material 3 may be optically transparent and thermally conductive. Examples of materials include single crystal SiC, sapphire, diamond, transparent crystals of the garnet and spinel groups. The optically transparent material 3 passes light from the laser diode chip 1 to the wavelength conversion material 4 and conducts heat from the wavelength conversion material 4 to the material 2. The optically transparent material 3 may disperse light incident from other elements. The top and bottom surfaces of the optically transparent material 3 may be smooth or textured. The textured surface can disperse light and is useful for improving the color uniformity of the light emitted from the top surface of the wavelength conversion material 4. In one embodiment, the thickness of the optically transparent material 3 may be about 100-250 μm, or about 20-50% of a lateral dimension of about 300-1000 μm. The shape of the optically transparent material 3 in a top view is not particularly limited and may be square, rectangular, hexagonal, octagonal, circular, or any other shape.

The wavelength conversion material 4 downconverts all or a portion of the light from the laser diode chip 1. The wavelength conversion material 4 may be formed and/or configured according to any of the embodiments described herein. An example of the wavelength conversion material 4 is YAG doped with Ce. In some embodiments, the wavelength conversion material 4 may include voids or other materials with different refractive indices to disperse the light. The wavelength conversion material 4 may be single crystal or sintered small particles. In some embodiments, the wavelength conversion material 4 may be a YAG/sapphire eutectic doped with Ce. In one embodiment, the thickness of the wavelength conversion material 4 is about 50-800 μm and the lateral dimensions are about 300-1000 μm. The shape of the wavelength conversion material 4 in a top view is not particularly limited and may be square, rectangular, hexagonal, octagonal, circular, or any other shape.

The reflector 5 reflects light incident from the side of the optically transparent material 3 and the wavelength converting material 4. The reflector 5 may cover all or part of the side of the optically transparent material 3 and the wavelength converting material 4 through which light can be emitted. Examples of shapes of the reflector 5 are shown in Figures 1B to 1C. If the light from the laser diode chip 1 is directly incident on the optically transparent material 3, the reflector 5 may be omitted from the area of the optically transparent material 3, i.e., the area where the laser diode chip 1 directs light to the optically transparent material 3. The reflector 5 may be a diffuse volume scatterer (e.g., _TiO2 or _{Al2O3 particles} in a matrix with a low refractive index such as glass, epoxy, or silicone). The reflector 5 may be a thin film coating (e.g., _SiO2 /Ag or Ag) on the sidewalls of the optically transparent material 3 and the wavelength converting material 4. The lateral thickness of the reflector 5 may be about 50 to 500 μm for a diffuse volume scatterer, and about 50 nm to 10 μm for a thin film coating. The height of the reflector 5 may be approximately equal to the thickness of the optically transparent material 3 plus the thickness of the wavelength converting material 4 .

Figure 2 is a simplified top view of a phosphor-integrated laser-based light source according to one embodiment of the present invention shown in Figures 1A-1D. In this example, a reflector 5 surrounds the sides of the wavelength converting material 4.

Figure 3 is a simplified perspective view of a phosphor-integrated laser-based light source according to another embodiment of the present invention. In this example, the reflector 5 is offset compared to the material 2 and extends over a portion of the laser diode chip 1. Also, the wavelength converting material 4 has a different shape than the material 2. This may be made clearer from the cross-sectional view of Figure 4, which shows a groove formed on the top of the material 2, with the optically transparent material 3 and the wavelength converting material 4 disposed above the groove. Figure 5 is a simplified perspective view of the material 2 according to one embodiment, with a groove formed on its top surface.

Figures 7A-7F are simplified diagrams illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. Figure 7A shows a laser diode chip 1 and a blank 2 assembled to a package base. The laser diode chip 1 and blank 2 can be bonded to the package base by, for example, a soldering process. Blank 2 has a groove formed on its top surface, and the light emitting opening of laser diode chip 1 is aligned with the groove so that light emitted from laser diode chip 1 enters the groove.

7B-7C show a partially diced sheet including a layer of optically transparent material and a layer of wavelength converting material. FIG. 7B shows a top view of the partially diced sheet, and FIG. 7C shows a perspective view. The optically transparent material and the layer of wavelength converting material may be bonded using an adhesive. In one embodiment, the adhesive may be optically transparent and may form a bond line between the optically transparent material and the wavelength converting material that is thin enough to allow efficient thermal transfer. Examples of adhesives include epoxy, silicone, glass, spin-on glass, or sol-gel formed materials. Preferred properties of the adhesive include high thermal conductivity, optical transparency, good adhesion, and stability under long term exposure to high temperatures and light flux.

As shown in Figures 7B-7C, the bonded material in a sheet may be diced into the desired shape. In this example, the sheet is diced into an octagonal shape. This requires multiple cuts at different angles. An octagonal shape does not utilize the sheet area as efficiently as a square shape, but the octagonal shape is closer to a circle and may be desirable in some applications.

7D-7E show reflective material 5 formed around the sides of an octagonal shaped optically transparent material 3 and wavelength converting material 4 ("octagonal shaped material"). Reflective material 5 may be a diffuse volume scatterer. Reflective material 5 may be applied around the octagonal shaped material after it has been diced and mounted on an octagonal shaped material dicing carrier, or after it has been removed and assembled on a new carrier at the desired spacing. In one embodiment, reflective material 5 may be applied or deposited in the gaps between the array of octagonal shaped materials. If necessary, a heat treatment may be used to harden and securely bond the reflective material 5 to the octagons. Alternatively, reflective material 5 may be deposited on the array of octagons and then removed by a planarization process such as grinding, polishing, or a squeegee if reflective material 5 is in a liquid or paste form. The octagonal shaped material surrounded by reflective material 5 may be singulated by a dicing process.

FIG. 7F shows the assembly of the octagonal shaped material surrounded by the reflector 5 to the laser diode chip 1 and material 2. The material used for attachment may be an optically transparent material such as epoxy, silicone, glass, spin-on glass, sol-gel formed material, etc. Alternatively, the material used for attachment may be solder or a similar material with metallized mating surfaces. In this case, the reflector 5 and/or the bottom surface of the optically transparent material 3 may be metallized in a pattern corresponding to that on the mating material 2. The metallization may function as a reflector. In one embodiment, the metallization may include _SiO2 /Ag/TiW/Au. Solder may be included in the metallization, in which case the stack may include _SiO2 /Ag/TiW/AuSn.

Figures 8A and 8B are simplified diagrams illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. These figures are similar to Figures 7A and 7F, except that the grooves in material 2 have different shapes and the optically transparent material 3 is metallized in a different pattern. Other steps may correspond to Figures 7B-7E and are not separately shown.

Figures 9A-9C are simplified cross-sectional views of a phosphor-integrated laser-based light source according to another embodiment of the present invention. The structure of this embodiment is similar to the embodiment shown in Figures 7A-7F, except that it includes a first laser diode chip 1a and a second laser diode chip 1b, and the material 2 has separate groove portions for each laser diode chip. Depending on the shape of the grooves, some embodiments provide separate grooves for each laser diode chip.

In the example shown in Figures 9A-9C, both laser diode chips 1a, 1b couple light into the groove. In some embodiments, the light from each of the laser diode chips 1a, 1b may be of substantially similar wavelengths (e.g., 440-460 nm), or the light from each of the laser diode chips 1a, 1b may be of different wavelengths (e.g., 450 nm and 590-650 nm, 450 nm and 850 nm, 450 nm and 905 nm, 450 nm and 940 nm, 450 nm and 980 nm, 450 nm and 405 nm, or any other wavelength). In some embodiments, one of the laser diode chips 1a, 1b may have an emission wavelength that is not downconverted (e.g., a red or infrared wavelength).

FIGS. 10A-10C are simplified cross-sectional views of a phosphor-integrated laser-based light source according to another embodiment of the present invention. This embodiment is similar to that of FIGS. 9A-9C, except that it includes laser diode chips 1a, 1b, 1c, 1d, each of which injects light into a separate portion of the groove. Alternate embodiments may include more than one laser diode chip, each of which injects light into a separate groove or separate portions of the groove. The size of the blank 2 may be increased to provide more space around the groove to accommodate the additional laser diode chips.

FIGS. 11A-11B are simplified cross-sectional views of a phosphor-integrated laser-based light source according to another embodiment of the present invention. FIG. 11B is similar to FIG. 11A, except that the reflector 5 has been removed and the light guide 1L is shown aligned with the groove in the optically transparent material 3. FIGS. 12A-12B are simplified diagrams showing a bottom view of the light guide 1L and the groove in the optically transparent material 3. The light guide 1L guides light from the laser diode chip 1 into the groove in the optically transparent material 3. The laser diode chip 1, material 2, optically transparent material 3, wavelength conversion material 4, and reflector 5 are otherwise similar to the corresponding features described with respect to FIGS. 1A-1D.

In this embodiment, the light guide 1L guides light from the laser diode chip 1 to a groove in the optically transparent material 3. The light enters the groove and is transmitted to the wavelength conversion material 4. The top surface of the material 2 may be covered with a reflective material that reflects the light that passes through the optically transparent material 3 upward.

The groove may be formed in the bottom surface of the optically transparent material 3. The groove may be U-shaped, V-shaped, grooved, or other shape. The groove may extend partially through the optically transparent material 3. The groove may be aligned with the light guide 1L or may be at an angle to the optical axis of the light guide 1L. The surface of the groove may be smooth or rough.

FIG. 13 is a simplified diagram showing a light guide structure according to one embodiment of the present invention. The light guide structure includes a light guide 1L (or waveguide) and a frame. In some embodiments, the light guide 1L may be tapered with a rectangular cross section, while in other embodiments, the light guide 1L may have other cross sections such as a circular shape. In some embodiments, the light guide 1L may have different taper angles, including no taper. The light guide 1L may include optical fiber. The structure providing the light guide 1L may provide mechanical support and/or aid in the assembly of the phosphor-integrated laser-based light source. The light guide 1L may include a low index material (cladding) surrounding the core material. The cladding may be formed, for example, by evaporating _MgF2 onto a glass core.

14A-14E are simplified diagrams illustrating a process for forming parts of a phosphor-integrated laser-based light source according to one embodiment of the present invention. In FIG. 14A, a blank 2 is placed on a package base. Blank 2 may be soldered or glued to the package base using an adhesive. In FIG. 14B, a light guide structure having light guides 1L is placed on blank 2. The light guide structure may be soldered or glued to blank 2 using an adhesive such as epoxy or silicone. Alternatively, the light guide structure may be part of an array of similar structures in a sheet that is glued to a sheet of blank (blank 2). In this embodiment, the light guide structure and blank 2 may be formed by a singulation process and then assembled on the package base. In either embodiment, the light guide structure may be formed from a glass substrate via known processes including, for example, deposition, patterning, etching, and singulation.

In FIG. 14C, the optically transparent material 3 and the wavelength converting material 4 are assembled on the material 2. The optically transparent material 3 and the wavelength converting material 4 may be formed in the manner as illustrated in FIG. 7B-7C described above, except that in this embodiment, a groove may be formed in the bottom of the optically transparent material as illustrated in FIG. 15A-15B. The groove in the bottom of the optically transparent material 3 is aligned with one end of the light guide 1L. The adhesive used for bonding may be optically transparent, such as epoxy, silicone, glass, spin-on glass, sol-gel formed material, etc. Alternatively, the material used for attachment may be solder or a similar material with metallized mating surfaces. In this case, the bottom surface of the optically transparent material 3 may be metallized as shown in FIG. 16. The metallization may function as a reflector. In one embodiment, the metallization may include SiO ₂ /Ag/TiW/Au. Solder may be included in the metallization, in which case the stack may include _SiO2 /Ag/TiW/AuSn.

In FIG. 14D, a reflector 5 such as a diffuse volume scatterer is formed around the sides of the optically transparent material 3 and the wavelength converting material 4. In FIG. 14E, the laser diode chip 1 is assembled to a package base. The laser diode chip 1 can be bonded to the package base by, for example, a soldering process. The light emitting opening of the laser diode chip 1 is aligned with the light guide 1L so that light emitted from the laser diode chip 1 is guided to the groove.

Figures 17A and 17B are simplified cross-sectional views of a phosphor-integrated laser-based light source according to another embodiment of the present invention. The structure of this embodiment is similar to the embodiment shown in Figures 14A-14F, except that it includes a first laser diode chip 1a and a second laser diode chip 1b, and the light guide structure has a separate light guide 1L for each laser diode chip. The light guides 1L are aligned to opposite ends of a single groove, as shown in Figure 17B, where the reflector 5 has been removed for clarity. In another embodiment, each light guide may be aligned to a separate groove.

In the example shown in Figures 17A-17B, both laser diode chips 1a, 1b couple light into the same groove. In some embodiments, the light from each of the laser diode chips 1a, 1b may be of substantially similar wavelengths (e.g., 440-460 nm), or the light from each of the laser diode chips 1a, 1b may be of different wavelengths (e.g., 450 nm and 590-650 nm, 450 nm and 850 nm, 450 nm and 905 nm, 450 nm and 940 nm, 450 nm and 980 nm, 450 nm and 405 nm, or any other wavelength). Figures 18A-18B are simplified diagrams showing bottom views of a light guide 1L at both ends of a groove in an optically transparent material 3 according to one embodiment.

Figures 19-21 are simplified cross-sectional views of phosphor-integrated laser-based light source packages according to some embodiments of the present invention. In Figure 19, an adhesive such as epoxy or solder is used to form a seal between the window or lid and the package sidewalls. The window can be glass or other optically transparent material that transmits light. The window, package sidewalls, and package base can hermetically seal the laser diode chip 1, material 2, optically transparent material 3, wavelength converting material 4, and reflector 5.

In FIG. 20, an adhesive such as glass solder, brazing material, or metal solder is used to form a seal between the window, lid, and the wall of the metal can. The seal between the metal can and the package base may be formed by projection welding. The wall of the metal can may block stray light from the laser diode 1. The window, walls, and package base may hermetically seal the laser diode chip 1, material 2, optically transparent material 3, wavelength converting material 4, and reflective material 5.

In FIG. 21, an adhesive such as epoxy or solder is used to form a seal between the metal flange and the reflector 5. The reflector 5 and wavelength converting material 4 may be non-porous to allow for a hermetic seal of the laser diode chip 1, material 2, and optically transparent material 3.

Figures 22A and 22B are simplified perspective views of a phosphor-integrated laser-based light source package according to another embodiment of the present invention. In this example, a light guiding structure, such as that described above with respect to Figures 11A-11B, forms part of the package housing. A seal is formed between the metal flange and the light guiding structure using an adhesive such as epoxy or solder. A seal is formed between the metal flange and the sidewall using an adhesive such as epoxy, solder, or by projection welding.

23A is a simplified cross-sectional view of a laser-based light source according to some embodiments of the present invention. The light source includes a laser diode 1 (or laser diode chip) disposed in a package base, with an output surface of the laser diode chip 1 arranged to emit light into a cavity or groove formed in a top surface of a material 2 (e.g., a thermally conductive material) and/or a bottom surface of an optical element 4, and/or a cavity between the material 2 and the optical element 4. Alternatively, light may be directly directed at the optical element 4. The laser diode 1 may be formed according to any of the embodiments described herein. The light source 1 may include one or more laser diodes, and the light may be laser light having a wavelength, for example, in the blue or other color region. The light may be directly incident from the laser diode 1 or may be incident via a light guide.

In some embodiments, the package base may be a printed circuit board (PCB). In other embodiments, the package base may be the bottom of a semiconductor package configured to conduct heat from the laser diode 1 and substrate 2 to an underlying structure such as solder, a metal core PCB, a heat sink, etc. The package base may also include a metal slug (e.g., Cu or Al), plated other metals, or a composite of metal and ceramic material (e.g., _AlN , _Al2O3 ). In yet another embodiment, the package base may be a slab of metal (e.g., Cu or Al) forming part of a metal core PCB such as a chip on board (COB).

In embodiments where the laser diode chip 1 emits light towards the groove, the groove may constitute an air gap between the blank 2 and the optical element 4. The top surface of the blank 2 and/or at least part of the inside of the groove may be covered with a reflective coating for directing and/or reflecting light upwards. The reflective coating may comprise, for example, silver (Ag) or aluminium (Al). Alternatively or additionally, the reflective coating may comprise an upper dielectric layer for environmental protection purposes and/or a dielectric stack, for example consisting of one or more layers of _SiO2 and/or _{Ta2O5 ,} for increased reflectivity. The reflective coating may be deposited as a flat specularly reflective film in case of a smooth surface or as a diffusely reflective rough film in case of uneven surfaces.

Material 2 at least partially directs and/or reflects light from laser diode 1 upwards towards optical element 4. Material 2 may have high thermal conductivity to conduct heat from optical element 4 to the package base. In some embodiments, material 2 may include silicon (S), silicon carbide (SiC), germanium (Ge), gallium arsenide (GaAs), sapphire, ceramic aluminum nitride (AlN), ceramic aluminum oxide (Al2O3), ceramic boron nitride (BN), aluminum (Al), copper (Cu), or other thermally conductive materials.

If material 2 is Si, the grooves can be formed by KOH etching to create angled sidewalls. A wide variety of groove shapes are possible. FIG. 6 illustrates a groove with a narrow neck that opens into a polygonal shape. In some embodiments, optical element 4 may have a similar shape to the groove. For example, FIG. 6 illustrates the profile of optically transparent material 3 with a polygonal shape similar to the groove. In some embodiments, the grooves may be partially or completely filled with diffuse volume scatterers (e.g., _TiO2 or _Al2O3 particles in a low refractive index matrix such as glass, epoxy, or _silicone ).

The optical element 4 may include a wavelength conversion material that downconverts all or a portion of the light from the laser diode 1. The wavelength conversion material may be diffused throughout the optical element 4. The optical element 4 may be formed and/or configured according to any of the embodiments described herein. One example of the optical element 4 is YAG doped with Ce. Another example of the optical element 4 may include YAG doped with Ce with eutectic sapphire. In some embodiments, the optical element 4 may include voids or other materials with different refractive indices to disperse the light. The optical element 4 may be single crystal or sintered small particles. In one embodiment, the optical element 4 has a thickness of about 50-800 μm or more and a lateral dimension of about 300-1000 μm. The shape of the optical element 4 in a top view is not particularly limited and may be square, rectangular, hexagonal, octagonal, circular, or any other shape.

The reflector 5 reflects light incident from the side of the optical element 4. The reflector 5 may cover all or part of the side of the optical element 4 from which light can be emitted. Examples of shapes of the reflector 5 are shown in Figures 1B to 1C. In cases where the light from the laser diode 1 is directly incident on the optical element 4, the reflector 5 may be omitted from the area where the laser diode 1 makes the light incident on the optical element 4. The reflector 5 may be a diffuse volume scatterer (e.g., _TiO2 or _{Al2O3 particles} in a matrix with a low refractive index such as glass, epoxy, or silicone). The reflector 5 may be a thin film coating (e.g., _SiO2 /Ag or Ag) on the sidewall of the optical element 4. The lateral thickness of the reflector 5 may be about 20 to 500 μm for a diffuse volume scatterer and about 50 nm to 10 μm for a thin film coating. The height of the reflector 5 may be approximately equal to the thickness of the optical element 4.

Figure 23B is a simplified plan view of a laser-based light source according to one embodiment of the present invention shown in Figure 23A. In this example, a reflector 5 surrounds the sides of the optical element 4.

24A-24D are simplified cross-sectional views of optical elements that can be used in any of the phosphor-integrated laser-based light sources according to some embodiments of the invention described herein. In the example shown in FIG. 24A, the optical element 4 includes a wavelength converting material. The thermal conductivity of the wavelength converting material need only be sufficient to conduct heat from the optical element 4 to the underlying material 2. In some embodiments that include a cavity between the optical element 4 and material 2, the thermal conductivity of the wavelength converting material need only be sufficient to conduct heat from the optical element 4 and around the cavity to the underlying material 2.

In the example shown in FIG. 24B, the optical element 4 includes a wavelength converting material 4a on top of an optically transparent thermal conductor 4b. The optically transparent thermal conductor 4b may be disposed between the wavelength converting material 4a and the material 2. The optically transparent thermal conductor 4b passes light from the laser diode 1 and the material 2 to the wavelength converting material 4a and conducts heat from the wavelength converting material 4a to the material 2 and the package base. The optically transparent thermal conductor 4b may be configured to disperse light incident from other elements to improve the color uniformity of the light emitted from the top surface of the optical element 4. Dispersion of light may occur at one or more interfaces of the optically transparent thermal conductor 4b and/or within the bulk of the optically transparent thermal conductor 4b.

In the example shown in FIG. 24C, the optical element 4 includes a wavelength converting material 4a and at least one optical homogenizer 4c. The at least one optical homogenizer 4c is configured to improve the color uniformity of the light emitted from the top surface of the optical element 4. The optical homogenizer 4c may be optically transparent (e.g., glass or sapphire) or at least partially translucent (e.g., Al2O3 ceramic). In some embodiments, the top surface of the optical homogenizer 4c may be textured and/or include optical dispersive features.

In the example shown in FIG. 24D, the optical element 4 includes a wavelength converting material 4a disposed between an optically transparent thermal conductor 4b and at least one optical homogenizer 4c. The optically transparent thermal conductor 4b may include features similar to those described with respect to FIG. 24B, and the at least one optical homogenizer 4c may include features similar to those described with respect to FIG. 24C.

25A and 25B are simplified cross-sectional views of laser-based light sources according to some embodiments of the present invention. The optical element 4 includes a wavelength converting material 4a disposed on an optically transparent thermal conductor 4b. Alternatively, the optical element may include any of the other configurations shown in FIGS. 24A-24D. In this particular embodiment, the wavelength converting material 4a may include features similar to those described with respect to FIG. 24A, and the optically transparent thermal conductor 4b may include features similar to those described with respect to FIG. 24B. The embodiment of FIGS. 25A and 25B also includes a light guide 1L. The light guide 1L may have features similar to those of the light guides described with reference to FIGS. 11-14. The light guide 1L is configured to guide light from the laser diode 1 to the optical element 4 or to a space or groove between the material 2 and the optical element 4. In embodiments including a space or groove, at least a portion of the light guide 1L may be disposed within the space or groove. In some embodiments, the light guide 1L may have light extraction features along at least a portion of its length, such as within a space or groove.

In the example of FIG. 25A, a cross-sectional view is shown showing the relative spatial arrangement of the various elements of this embodiment. Light emitted from the laser diode 1 is transmitted by the light guide 1L to the transparent thermal conductor.

In the example of FIG. 25B, a cutaway view is shown illustrating the relative spatial arrangement of the various elements of this embodiment. As can be seen, the wavelength converting material 4a and the optically transparent thermal conductor 4b may have a polygonal shape surrounded by the reflector 5.

Figures 26A and 26B are simplified cross-sectional views of laser-based light sources according to some embodiments of the present invention. This embodiment is similar to that of Figures 25A-25B, except that the light guide 1L is disposed at an angle relative to the laser diode 1 and the optical element 4 (in this embodiment, the optically transparent thermal conductor 4b). Other angles are possible in other embodiments, and the angle is not limited to any particular angle.

In the example of FIG. 26A, a cross-sectional view is shown showing the relative spatial arrangement of the various elements of this embodiment, including the angle of the light guide 1L that extends between the laser diode 1 and the optical element 4.

In the example of FIG. 26B, a cutaway view is shown showing the relative spatial arrangement of the various elements of this embodiment. As previously mentioned, the light guide 1L may be configured to guide light from the laser diode 1 to the optical element 4 or to a space or groove between the material 2 and the optical element 4.

27A and 27B are simplified cross-sectional views of laser-based light sources according to some embodiments of the present invention. The optical element 4 includes a wavelength converting material 4a disposed on an optically transparent thermal conductor 4b. The wavelength converting material 4a may include features similar to those described with respect to FIG. 25A, and the optically transparent thermal conductor 4b may include features similar to those described with respect to FIG. 25B. The embodiments of FIGS. 27A and 27B also include a light guide 1L. The light guide 1L may have features similar to those of the light guides described with reference to FIGS. 11-14. In the illustrated embodiment, between the material 2 and the optically transparent thermal conductor 4b there is a cavity formed as a space or groove in the bottom surface of the optically transparent thermal conductor 4b. A portion of the light guide 1L is disposed in the groove. The light guide 1L may have light extraction features along a portion of its length, for example within the groove.

In the example of FIG. 27A, a cross-sectional view is shown showing the relative spatial arrangement of various elements of this embodiment, including a light guide 1L that extends into the cavity between the material 2 and the optical element 4.

The example in Figure 27B shows a cutaway view illustrating the relative spatial arrangement of the various elements of this embodiment. It also shows how the light guide 1L extends into the cavity.

28A and 28B are simplified cross-sectional and plan views of a laser-based light source according to some embodiments of the present invention. In the illustrated embodiment, a gap extends between the optical element 4 and the reflector 5. The reflector 5 reflects light incident on the side of the optical element 4 and covers all or part of the side area of the optical element 4 from which light can exit. In some embodiments, the portion of the optical element 4 on which light from the laser diode 1 is incident may not be covered by the reflector 5.

In the example of Figure 28A, a cross-sectional view is shown showing the relative spatial arrangement of the various elements of this embodiment, including the gap between the optical element 4 and the reflector 5.

The example in Figure 28B shows a top view of the relative spatial arrangement of the various elements of this embodiment in the orientation shown in Figure 28A.

29A-29C are simplified side, perspective, and cutaway views of a laser-based light source according to some embodiments of the present invention. In the illustrated embodiment, a gap extends between the optical element 4 and the reflector 5. In some embodiments, for example, due to tolerances, a nominally small gap may exist between the optical element 4 and the reflector 5. From an optical standpoint, it may be desirable for the gap to be, for example, up to about 40 um, up to about 50 um, up to about 60 um, or more. The gap may have other sizes depending, for example, on different materials, shapes, manufacturing processes, and/or assembly techniques.

In some embodiments, the reflector 5 may be formed separately, for example, via a sintering process, a high temperature ceramic process, or a particle-in-glass process, and then interspersed with the optical element 4. In some embodiments, the reflector 5 has diffusive properties. In some embodiments, the reflector 5 is formed of a material such as TiO2 or BaTiO3 particles co-sintered with a transparent low refractive index material (e.g., glass, SiO2, or Al2O3). In some embodiments, the reflector 5 may be formed separately (e.g., by a sintering process) and then assembled to the optical element 4. In another embodiment, the reflector 5 may include an element having a reflective film or coating on the inner wall (or wall portion) facing the optical element 4. As an example, the reflector 5 may be a silicon element with holes created by an etching process (e.g., reactive ion etching), and the silicon element may include a reflective coating (e.g., Ag coating) on the inner wall (or wall portion) facing the optical element 4.

The examples of Figures 29A and 29B show side and perspective views, respectively, illustrating the relative spatial arrangement of various elements of this embodiment. The example of Figure 29C shows a cutaway view, illustrating how light is incident directly or through light guide 1L into a cavity on the top surface of material 2 according to this embodiment. In alternative embodiments, light may be emitted to optical element 4, to a cavity on the bottom surface of optical element 4, or to a cavity between material 2 and optical element 4.

30A and 30B are simplified cross-sectional and plan views of a laser-based light source according to some embodiments of the present invention. In the illustrated embodiment, element 2b is included. Element 2b may be a reflective element. Laser diode 1 irradiates light into a cavity between material 2, element 2b, and optical element 4. There may be multiple devices with light incident from different locations. Light may be emitted from laser diode 1 directly or through a light guide 1L (not shown), which may extend at least partially into the cavity, for example. The cavity may be formed, for example, by a groove in the top surface of material 2 and a through hole in reflective element 2b.

In some embodiments, material 2 redirects incident light partially upwards. Additionally, reflective element 2b may also redirect incident light partially upwards. Reflective element 2b may also serve as a mechanical support for optical element 4 and/or reflector 5. Reflective element 2b may be configured to conduct heat from optical element 4 through material 2 to the package base.

31A and 31B are simplified cutaway views of laser-based light sources according to some embodiments of the present invention. In the illustrated embodiments, different shapes of element 2b are shown. In some embodiments, element 2b may be formed by, for example, wafer fabrication techniques including photolithography, etching, and deposition, photochemical etching including using different masks for the top and bottom ("half etching"), or pressing and shaping sheet metal. Materials for reflective element 2b include, for example, Si, Ge, sapphire, SiC, glass, various metals, etc. In some embodiments, the material has a reflective coating.

31A and 31B are cutaway cross-sectional views showing the relative spatial arrangement of various elements of this embodiment, including element 2b. In the example of FIG. 31A, element 2b has a relatively flat shape with a through hole through which light passes. In the example of FIG. 31B, element 2b also extends around the side of reflector 5.

FIGS. 32A-32C are simplified cross-sectional, perspective, and cut-away cross-sectional views of laser-based light sources according to some embodiments of the present invention. In the illustrated embodiment, another element 2b is shown. As shown in FIG. 32C, element 2b has a step feature that provides clearance between element 2b and the top surface of laser diode 1. In some embodiments, the clearance can be used, for example, for wire bonds on the top surface of laser diode 1.

33A and 33B are simplified cross-sectional and plan views of a laser-based light source according to some embodiments of the present invention. In the illustrated embodiment, element 24b is included. Laser diode 1 irradiates light into a cavity between material 2, element 24, and optical element 4. There are multiple possible devices for injecting light from different locations. Light can be emitted from laser diode 1 directly or through a light guide 1L (not shown), which may, for example, be at least partially disposed in the cavity. The cavity between material 2, element 24, and optical element 4 may, for example, be formed by a groove on the top surface of material 2. Element 24 may be an element or material that directs a portion of the incident light upwards, and may be formed as a topological feature of material 2. In some embodiments, element 24 is distinct from material 2.

In some embodiments, material 2 includes step features that redirect incident light partially in an upward direction, and element 24 may also function to redirect incident light partially in an upward direction.

Figures 34A-34D are simplified perspective and cutaway views of laser-based light sources and components according to some embodiments of the present invention. In the illustrated embodiment, material 2 is shown having a groove or cavity and a through hole. Additionally, the top of material 2 may include element 24. Element 24 may bond material 2 to optical element 4. In some embodiments, a groove is formed in material 2. Light from laser diode 1 is incident on the groove. The inner walls of the groove, including the top and bottom, may have a highly reflective coating to minimize absorption losses. In some embodiments, material 2 may be comprised of a bottom piece having a groove and element 24 that is bonded to form the groove.

Figures 34A and 34B are simplified perspective and cutaway views of laser-based light sources according to some embodiments of the present invention. In the illustrated embodiment, an optical element 4 and a reflector 5 are disposed on top of an element 24 and a material 2. Laser diodes 1 are disposed on either side of the groove with light incident on both ends. Material 2 includes step features within the groove to partially direct the incident light upwards. These figures show that light emitted from laser diode 1 is directed upwards through a hole in element 24 to optical element 4.

In the example of FIG. 34B, a cutaway view is shown showing the relative spatial arrangement of the various elements of this embodiment. In this example, the groove includes a step or ramp feature to facilitate directing light upward through the hole to the optical element 4.

In the example of FIG. 34D, a perspective view is shown showing the relative spatial arrangement of the various elements of this embodiment, including how the top surface of element 24 forms the base or support for optical element 4 (not shown).

35A and 35B are simplified perspective and cutaway views of a laser-based light source according to some embodiments of the present invention. In the illustrated embodiment, a packaging configuration is illustrated. The packaging structure is adapted to house a laser-based light source according to some embodiments of the present invention, and includes a lid and a window. The lid may be metal, ceramic, plastic, or other material, and the window may be transparent. In this example, the lid is square-shaped (including rectangular) with rounded corners and a ridge around the base. Other shapes may be employed in accordance with embodiments described herein. In some embodiments, a seal between the window and the lid is formed, for example, with glass frit, brazing material, solder, epoxy, or other sealant. A seal between the lid and the package base may be formed, for example, with projection welding, glass frit, brazing material, solder, epoxy, or other methods.

In some embodiments, the window is made of glass or other transparent material. The shape of the window may be flat or may include topological features such as curvature. The window may include, for example, a lens that is flat or has a topology that varies in thickness laterally. The window may include optical coatings, such as anti-reflective coatings or wavelength filters, on one or both sides. Additionally, in some embodiments, the window may have diffractive or dispersive features formed on one or both sides, or in the bulk.

In the example of FIG. 35A, a perspective view is shown illustrating the relative spatial arrangement of various elements of the present embodiment, and in the example of FIG. 35B, a cutaway view is shown illustrating the relative spatial arrangement of various elements of the present embodiment, including an exemplary laser-based light source described herein. Other laser-based light sources may be used in the package.

36A and 36B are simplified perspective and cutaway views of a laser-based light source according to some embodiments of the present invention. In the illustrated embodiment, a packaging configuration is illustrated. The packaging structure is adapted to house a laser-based light source according to some embodiments of the present invention, and includes a lid and an opening. Thus, in this embodiment, a top surface of the optical element 4 may be exposed through the opening. A portion of the reflector 5 may be exposed through the opening. The lid may be metal, ceramic, plastic, or other material. The seal between the lid and the element 24, the seal between the element 24 and the optical element 4, the seal between the lid and the frame, and the seal between the frame and the package base may be formed, for example, of glass frit, brazing material, solder, epoxy, or other material. In some embodiments, the lid may integrally include the frame.

In the example of FIG. 36A, a perspective view showing the relative spatial arrangement of various elements of the present embodiment is shown, and in the example of FIG. 36B, a cutaway view showing the relative spatial arrangement of various elements of the present embodiment including an exemplary laser-based light source described herein is shown. Included is a close-up of a portion of the laser-based light source showing material 2, element 24, optical element 4, and reflector 5. Other laser-based light sources may be used in the package.

Figures 37A-37C are simplified perspective views of a laser-based light source and various component structures according to some embodiments of the present invention. In the illustrated embodiments, the light guide is formed in or on a substrate or package base. A light source 1 is mounted on the substrate, for example with an emitting aperture on or near the substrate, and light enters the light guide from the light source 1. The light guide is disposed below the optical element 4 and the reflector 5, and may have features that extract light and direct it upward from the bottom surface of the optical element 4. In some embodiments, the light guide may be formed by, for example, thin film deposition techniques or sol-gel processes.

In the example of FIG. 37A, a perspective view is shown showing the relative spatial arrangement of the various elements of the present embodiment. In the examples of FIGS. 37A-37C, perspective views are shown showing the relative spatial arrangement of the various elements of the light guide without the substrate, laser diode 1, optical element 4, and reflector 5. In the example of FIG. 37C, a close-up perspective view is shown showing pads that may be included on the substrate for attachment of the optical element 4. The light guide may be divided into multiple sections to enhance and/or improve the uniformity of light extraction to the optical element 4.

38A-38C are simplified perspective views of a laser-based light source and various component structures according to some embodiments of the present invention. In the illustrated embodiment, the optical element 4 is positioned above the light source in the arrangement shown. The light source may, for example, have two laser diodes or laser diode chips 1a and 1b mounted on a single submount. Grooves on the bottom side of the optical element 4 or optically transparent thermal conductor 4b and reflector 5 align the laser diode chips 1a and 1b with the reflector providing clearance during assembly. The top surface of the submount corresponding to the bottom surface of the optically transparent thermal conductor 4b may have a reflective coating to direct light upwards towards the optical element 4. In some embodiments, only one laser chip or more than two laser chips are mounted on the submount and the reflector redirects the light emitted from all the chips towards the optical element 4.

In the example of FIG. 38A, a perspective view is shown showing the relative spatial arrangement of the various elements of the present embodiment. In the example of FIG. 38B, a perspective view of the bottom of the optically transparent thermal conductor 4b and the reflector 5 is shown, showing the relative spatial arrangement of the various elements of the present embodiment, including the grooves. In the example of FIG. 38C, a perspective view of the submount with the optical element 4 and the reflector 5 removed is shown, showing the relative spatial arrangement of the various elements of the present embodiment, including the reflector.

As described elsewhere herein, the material 2 may be configured to redirect a portion of the incident light from the light source 1 to the optical element 4. There are other elements that redirect the direction of light. For example, in some embodiments, a light guide 1L present in the structure can guide the light from the laser diode 1 at least partially to the optical element 4. In some embodiments, a cavity is present in the structure between the material 2 and the optical element 4, and the shape of the cavity and the interface between the cavity and the optical element 4 can additionally or alternatively direct the light from the light source 1 partially upwards to the optical element 4. In some embodiments, the optical element 4 has an interface between the wavelength conversion material 4a and the optically transparent thermal conductor 4b, and the interface can be configured to redirect the light within the optical element 4.

Figures 39-45 are simplified perspective views of an example of a material 2 for a laser-based light source according to some embodiments of the present invention. The illustrated embodiments show examples of achieving light redirection that can be used to provide more uniform illumination at the bottom of the optical element 4. In some embodiments, by directing light from the light source 1 partially at a high angle from normal to the optical element 4, the illuminance of the unconverted light becomes more uniform across the lateral cross-section of the optical element 4. As a result, the spatial color uniformity of the light emerging from the top surface of the optical element 4 can be improved.

39A-39C are simplified perspective views of an example of a material 2 for a laser-based light source according to some embodiments of the present invention. The illustrated embodiment has grooves that advantageously redirect light from the light source 1 to the optical element 4 with high uniformity. The grooves in the illustrated embodiment have a rectangular pattern layout formed by standard crystallographic etching techniques, for example, used to etch silicon substrates. The illustrated embodiment is provided as a non-limiting example. Other groove configurations are contemplated. In some embodiments, the groove surface is smooth. In some embodiments, the groove surface has scattering and/or diffractive features. In some embodiments, the groove surface has or incorporates photonic crystal structures. In some embodiments, the scattering and/or diffractive features are formed in an underlying material with a reflective thin film coating on top. In some embodiments, the scattering and/or diffractive features are formed on a smooth surface coated with a reflective coating, and a coating having the desired features is formed thereon. For example, in some embodiments, a coating containing high refractive index particles in a low refractive index binder is used. In some embodiments, a dielectric layer is used with features etched into its surface.

In the example of FIG. 39A, material 2 includes a single groove to facilitate directing light to optical element 4. The example of FIG. 39B is similar, except material 2 includes multiple offset grooves. A separate laser diode 1 is disposed in each groove. The example of FIG. 39C is similar, except that the grooves are aligned. The grooves in these examples may have a rectangular shape that is suitable for formation by, for example, crystallographic etching of silicon.

40A-40C are simplified perspective views of an example of a material 2 for a laser-based light source according to some embodiments of the present invention. The illustrated embodiment has grooves that advantageously redirect light from one or more light sources 1 to an optical element 4 with high uniformity. The grooves of the illustrated embodiment have a layout with curvatures. The curvatures can spread the reflected light over a wider range of angles compared to sidewalls that are comprised of flat surfaces. The illustrated embodiment is provided as a non-limiting example. Other groove configurations are contemplated. In some embodiments, the groove surface is smooth. In other embodiments, the groove surface has scattering and/or diffractive features. In some embodiments, the groove surface has or incorporates a photonic crystal structure. In some embodiments, the scattering and/or diffractive features are formed in an underlying material with a reflective thin film coating on top. In some embodiments, the scattering and/or diffractive features are formed on a smooth surface that is coated with a reflective coating, and further reflective coatings and/or other coatings having desired features may be formed thereon. For example, in some embodiments, a coating containing high refractive index particles in a low refractive index binder may be used. In some embodiments, a dielectric layer with features etched into the surface may be used. The groove may include a cavity, as shown in the example of FIG. 40A.

Figure 41 is a simplified perspective view of an example of a material 2 for a laser-based light source according to some embodiments of the present invention. The illustrated embodiment has grooves that advantageously redirect light from the light source 1 to the optical element 4 with high uniformity. The illustrated grooves have steps. The steps can be formed, for example, by performing two or more etching processes with different mask layouts. The illustrated embodiment provides a non-limiting example. Other groove arrangements are contemplated. For example, in some embodiments, one or more of the grooves may have more than one step. Additional grooves may be included for use in embodiments having multiple light sources.

FIGS. 42A and 42B are simplified perspective views showing the profile of the sidewalls of the grooves of the material 2 according to some embodiments of the present invention. As shown, in some embodiments, the profile of the sidewalls of the grooves is linear with a slope. The slope may be any slope desired to improve the uniformity of the injection of light into the optical element 4, which may improve the color uniformity of the light emitted from the top surface of the optical element 4.

43A and 43B are simplified perspective views showing the profile of the sidewalls of the grooves of the material 2 according to some embodiments of the present invention. As shown, in some embodiments, the profile of the sidewalls of the grooves is curved. The curvature can be of various shapes that can spread the reflected light over a wider range of angles compared to sidewalls that are constructed with flat surfaces. Thus, the curvature can be of any desired slope that improves the uniformity of the injection of light into the optical element 4, which can contribute to improving the color uniformity of the light emitted from the top surface of the optical element 4. Although these examples show grooves formed on the top surface of the material 2, in alternative embodiments, similar grooves can be formed on the bottom surface of the optical element 4.

Figure 44 is a simplified perspective view of an example of a material 2 for a laser-based light source according to some embodiments of the present invention. The illustrated embodiment has grooves that advantageously redirect light from the light source 1 to the optical element 4 with high uniformity. The grooves of the illustrated embodiment have scattering volume elements. The scattering volume elements are configured to disperse incident light from the laser diode 1 to the optical element 4. In some embodiments, the scattering volume elements include high refractive index particles in a low refractive index binder. In some embodiments, the low refractive index binder may include high refractive index particles. The scattering volume elements may be formed by applying (e.g., dispensing) a liquid or paste-like material and then curing it into a solid. In some embodiments, the scattering volume elements are additionally or alternatively formed in grooves in the bottom surface of the optical element 4.

Figures 45A-45B are simplified perspective views of an example of a material 2 for a laser-based light source according to some embodiments of the present invention. The illustrated embodiment has a groove that can advantageously redirect light from the light source 1 to the optical element 4 with high uniformity. In the illustrated embodiment of the groove, a transparent or semi-transparent optical element is disposed in the groove. One or more surfaces of the transparent or semi-transparent optical element may have dispersive features, diffractive features, or photonic crystal structures. In some embodiments, the transparent or semi-transparent optical element is attached to the groove as shown. In some embodiments, the transparent or semi-transparent optical element is additionally or alternatively attached to the bottom surface of the optical element 4 or inside a groove formed in the bottom surface of the optical element 4. In some embodiments, the optical element can also act as a light guide 1L for light injected from the light source 1 into the cavity between the material 2 and the optical element 4.

In the example of FIG. 45A, the optical element does not extend to the outside of the groove. In the example of FIG. 45B, the optical element extends to the outside of the groove. For example, when using the optical element as a light guide 1L, it may be advantageous for the optical element to extend to the outside of the groove.

Figure 46 includes simplified perspective and exploded views of components of a laser-based light source according to one embodiment of the present invention. In the illustrated embodiment, diffractive or dispersive features are illustrated. These features may be used to enhance the color uniformity of the light emitted from the top surface of the optical element 4. In some embodiments, the top surface of the optically transparent thermal conductor 4b may include dispersive features, diffractive features, photonic crystal structures, for example, as shown. These features may include air bubbles or may be filled in whole or in part with a material having a different refractive index than one or more of the optically transparent thermal conductor 4b and the wavelength converting material 4a.

In some embodiments, the dispersive features, diffractive features, or photonic crystal structures may be formed at the interface between the wavelength converting material 4a and the optically transparent thermal conductor 4b. In some embodiments, the dispersive features, diffractive features, or photonic crystal structures may be additionally or alternatively formed on the bottom surface of the wavelength converting material 4a and/or the bottom surface of the optically transparent thermal conductor 4b. In some embodiments, the dispersive features, diffractive features, or photonic crystal structures may be additionally or alternatively formed on the bottom surface of the optical element 4. The dispersive features, diffractive features, or photonic crystal structures formed on the bottom surface of the aforementioned elements may cover the entire bottom surface or a portion of the bottom surface. For example, the features may partially cover the bottom surface where light from one or more laser diodes 1 enters the optical element 4. In some embodiments, the dispersive features, diffractive features, or photonic crystal structures may be additionally or alternatively formed on the top surface of the optical element 4, the wavelength converting material 4a, the optically transparent thermal conductor 4b, and/or the optical homogenizer 4c. Dispersive features may also be formed within the optical element 4 (including the wavelength converting material 4a, the optically transparent thermal conductor 4b, and/or the optical homogenizer 4c, if present). The features may be distributed throughout the optical element 4 or may be concentrated in particular layers within the optical element 4. For example, dispersive features may be formed in volumes near the top and/or bottom of the optical element 4, or on the top and/or bottom of various regions of the optical element 4.

The dispersion features, diffractive features, and photonic crystal structures may have a variety of shapes, geometric features, and spacing distances, and the shapes, sizes, and geometric features are not limited. In some embodiments, the size and spacing of the dispersion features, diffractive features, or photonic crystal structures are near the wavelength of visible light, e.g., 50-1000 nm.

In some embodiments, the pattern of the dispersive features, diffractive features, or photonic crystal structures is regular, as shown in the example of FIG. 46. In some embodiments, the dispersive features, diffractive features, or photonic crystal structures are defined by holography, conventional photolithography, nanoprint lithography, or a similar process. In some embodiments, the pattern of the dispersive features, diffractive features, or photonic crystal structures is regular or random. In some embodiments, the features are defined, for example, by nanosphere lithography. In some embodiments, the distribution pattern of the dispersive features, diffractive features, or photonic crystal structures is the result of roughness caused, for example, by mechanical or chemical etching processes. In some embodiments, a lithographically defined mask is not used.

It will be understood that the number of laser diodes or chips used in each of the embodiments described herein is not limited. For example, any of the embodiments may be used in a single or multiple laser diode 1 configuration, as shown in the examples of Figures 10A and 10B or Figures 34A-35D. Additionally, in some embodiments, one or more laser diodes 1 may emit light in a blue wavelength range, a violet wavelength range, an infrared (IR) wavelength range, or a combination thereof including different IR wavelengths. For example, some embodiments may include one or more laser diodes emitting light in a blue wavelength range, one or more laser diodes emitting light in a first IR wavelength range (e.g., 850 nm), and one or more laser diodes emitting light in a first IR wavelength range (e.g., 905 nm). Other embodiments may include various other combinations of laser diodes in blue, violet, and IR wavelengths (e.g., IR wavelengths of 850 nm, 905 nm, 940 nm, 1300 nm, 1550 nm, etc.).

The methods, systems, and devices described above are examples. In various configurations, various steps and components may be omitted, substituted, or added, as appropriate. For example, in alternative configurations, the methods may be performed in an order different from that described, and/or various steps may be added, omitted, and/or combined. Also, features described with respect to a particular configuration may be combined in various other configurations. Different aspects or elements of the configurations may be combined in a similar manner. Elements Also, technology evolves, and therefore many elements are exemplary and do not limit the scope of the disclosure or claims.

FIG. 37A is a simplified perspective view of a laser-based light source and various component structures according to some embodiments of the present invention. FIG. 37B is a simplified perspective view of a laser-based light source and various component structures according to some embodiments of the present invention. FIG. 37C is a simplified perspective view of a laser-based light source and various component structures according to some embodiments of the present invention.

FIG. 38A is a simplified perspective view of a laser-based light source and various component structures according to some embodiments of the present invention. FIG. 38B is a simplified perspective view of a laser-based light source and various component structures according to some embodiments of the present invention. FIG. 38C is a simplified perspective view of a laser-based light source and various component structures according to some embodiments of the present invention.

Claims (24)

Package base,
a laser diode chip coupled to the package base, the laser diode chip configured to output a laser beam of electromagnetic radiation at a first wavelength from an output face;
a material having a reflective surface coupled to the package base and positioned adjacent to the laser diode chip on the package base;
an optical element directly bonded to a top surface of the material, a groove extending between the material and the optical element, the groove being aligned with a laser diode chip to receive electromagnetic radiation from the laser diode chip, the material being configured to direct at least a portion of the electromagnetic radiation in the groove towards the optical element, the optical element including a wavelength conversion material configured to convert at least a portion of the electromagnetic radiation in the laser light having a first wavelength to a second wavelength longer than the first wavelength;
a reflector surrounding a side surface of the optical element, the reflector configured to reflect a portion of electromagnetic radiation incident on the side surface of the optical element configured to emit light from a top surface thereof including a first portion having the first wavelength and a second portion having a second wavelength;
1. A laser-based light source comprising: The laser-based light source of claim 1, further comprising one or more additional laser diode chips and one or more additional grooves, each of the one or more additional laser diode chips aligned with one of the additional grooves, and the one or more additional laser diode chips configured to emit electromagnetic radiation at the first wavelength. The laser-based light source of claim 1, further comprising one or more additional laser diode chips and one or more additional grooves, each of the one or more additional laser diode chips aligned with one of the additional grooves, and at least one of the one or more additional laser diode chips configured to emit electromagnetic radiation at a second wavelength different from the first wavelength. The laser-based light source of claim 1, wherein the groove is formed in an upper portion of the material and extends from a side of the material to reflect at least a portion of the electromagnetic radiation upwardly toward the optical element. The laser-based light source of claim 1, wherein the material is thermally conductive and includes silicon (S), silicon carbide (SiC), germanium (Ge), gallium arsenide (GaAs), sapphire, ceramic aluminum nitride (AlN), ceramic aluminum oxide (Al2O3), ceramic boron nitride (BN), aluminum (Al), or copper (Cu), and the reflective surface has a reflective coating on the material. The laser-based light source of claim 1, wherein the wavelength converting material is diffused throughout the optical element. The laser-based light source of claim 1, wherein the upper portion of the optical element has an optical homogenizer that improves the color uniformity of the light emitted from the upper surface of the optical element. The laser-based light source of claim 1, wherein at least one of the sides, top, or bottom of the groove is covered with a reflective coating. The laser-based light source of claim 1, wherein a gap extends between at least some sides of the optical element and the reflector. The laser-based light source of claim 1, further comprising a dispersing material in the groove, the dispersing material in the groove configured to at least partially disperse electromagnetic radiation from the laser diode chip into the optical element. The laser-based light source of claim 1, wherein the groove has a sidewall with a flat surface or a sidewall with a curved portion. The laser-based light source of claim 1, wherein the reflector has a reflective coating on an inner wall of the reflector. The laser-based light source of claim 1, wherein the optical element includes at least one of a dispersive feature, a diffractive feature, or a photonic crystal structure that provides color uniformity for light emitted from the top surface of the optical element. The laser-based light source of claim 13, wherein the reflector has a reflective coating on an inner wall of the reflector. A surface mounted device (SMD) including the laser-based light source of claim 1. Package base,
a laser diode chip coupled to a package base, the laser diode chip configured to output a laser beam of electromagnetic radiation from an output face, the laser diode chip configured to output electromagnetic radiation at a first wavelength;
a material having a reflective surface coupled to the package base and positioned adjacent to the laser diode chip on the package base;
an optical element bonded directly to a top surface of the material;
a light guide having one end aligned with an output face of the laser diode chip and another end aligned with the optical element, the light guide being configured to guide at least a portion of the electromagnetic radiation from the laser diode chip to the optical element, the optical element including a wavelength conversion material configured to at least partially receive the electromagnetic radiation emitted to the optical element, the wavelength conversion material configured to convert at least a portion of the electromagnetic radiation in a laser light having a first wavelength to a second wavelength longer than the first wavelength;
a reflector surrounding a side surface of the optical element, the reflector configured to reflect a portion of electromagnetic radiation incident on the side surface of the optical element configured to emit light from a top surface thereof including a first portion having the first wavelength and a second portion having a second wavelength;
1. A laser-based light source comprising: The laser-based light source of claim 16, further comprising a groove extending between a portion of the material and a portion of the optical element, a second laser diode chip, and a second light guide, the light guide aligned with a first end of the groove, the second light guide aligned with a second end of the groove, and the second light guide configured and arranged to guide second electromagnetic radiation from the second laser diode chip to the groove. The laser-based light source of claim 16, wherein the material is thermally conductive and includes silicon (S), silicon carbide (SiC), germanium (Ge), gallium arsenide (GaAs), sapphire, ceramic aluminum nitride (AlN), ceramic aluminum oxide (Al2O3), ceramic boron nitride (BN), aluminum (Al), or copper (Cu), and the reflective surface has a reflective coating on the material. The laser-based light source of claim 16, wherein the wavelength converting material is diffused throughout the optical element. The laser-based light source of claim 16, wherein the upper portion of the optical element has an optical homogenizer that improves color uniformity of the light emitted from the upper surface of the optical element. The laser-based light source of claim 16, wherein a gap extends between at least some sides of the optical element and the reflector. The laser-based light source of claim 16, comprising a groove extending between a portion of the material and a portion of the optical element, and a dispersing material disposed in the groove, the dispersing material in the groove configured to disperse electromagnetic radiation from the laser diode chip to the optical element. A surface mounted device (SMD) including the laser-based light source of claim 16. 17. The laser-based light source of claim 16, wherein the optical element includes at least one of dispersive features, diffractive features, or photonic crystal structures that provide color uniformity for light emitted from the top surface of the optical element.