HK1061927A - Organic laser cavity arrays - Google Patents

Description

Organic laser cavity array

Technical Field

The present invention relates generally to Vertical Cavity Surface Emitting Lasers (VCSELs) or microcavities, and more particularly to organic microcavity lasers or organic VCSELs. More particularly, the present invention relates to various arrays of organic laser cavities.

Background

Vertical Cavity Surface Emitting Lasers (VCSELs) made based on inorganic semiconductors such as AlGaAs have been developed since the mid-eighties (see Kinoshita et al, IEEEjournal of Quantum Electronics, Vol. QE-23, No.6, 6/1987). This level has been reached by many companies making AlGaAs-based VCSELs emitting at 850nm, which have lifetimes exceeding 100 years (Choquette et al Proceedings of the IEEE, Vol.85, No11, 11 months 1997). With the success of the development of these near infrared Lasers, attention has recently turned to the production of VCSELs Emitting in the visible wavelength range using other inorganic material systems (Wilmsen, Vertical-Cavity Surface-Emitting Lasers, cambridge university press, cambridge, 2001). Visible lasers have many potential uses, such as display, optical storage read/write, laser printing, and rectangular communication using plastic optical fibers (Ishigure et al, Electronics Letters, 16)^th，193 months in 95 years, Vol.31, No. 6). Despite the global efforts of multiple industrial and scientific laboratories, there is still much work to be done to design visible radiation laser diodes (edge emitters or VCSELs) to produce light output across the visible spectrum.

In attempting to produce VCSELs at visible wavelengths, it is beneficial to forego inorganic-based systems and focus on organic-based laser systems because organic-based gain materials have many advantages over inorganic-based gain materials in the visible spectral range. For example, typical organic-based gain materials have low unpumped scattering/absorption losses and high quantum efficiency. Organic lasers are relatively inexpensive to manufacture compared to inorganic laser systems, emit across the visible range, can be made to any size, and most importantly, can radiate multiple wavelengths (e.g., red, green, and blue) from a single crystal. Interest in the fabrication of organic-based solid state lasers has grown over the past several years. The laser gain material is either a high polymer material or a small molecule material and has a plurality of different resonant cavity structures such as microcavities (Kozlov et al, U.S. Pat. No.6,160,828, 12.12.2000), waveguides, ring micro lasers, and distributed feedback (see also Kranzelbinder et al, Rep. prog. Phys.63, (2000) 729-. A common problem with these structures is that in order to generate the laser light, the cavity must be excited by optical pumping with other laser sources. Electrically pumping this laser cavity is better because it generally becomes more compact and easier to modulate the structure.

The main obstacle to electrical pumping of organic lasers is the low carrier mobility of the organic materials, typically around 10^-5cm²V-s. The low carrier mobility causes many problems. Devices with low carrier mobility are generally limited to the use of thin film layers to avoid large voltage drops and ohmic heating. These thin film layers cause the laser mode to penetrate to the high loss cathode and anode, resulting in much higher laser threshold (Kozlov et al, Journal of Applied Physics, Vol.84, No.8, 10/15/1998). Due to the recombination of electron holes in the organic materialThe law (the recombination rate is measured by carrier mobility), so low carrier mobility results in a higher number of carriers than a singlet excimer; one consequence of this is that charge-induced (polaron) absorption energy becomes an important loss mechanism (Tessler et al, Applied Physics Letters, Vol.74, No.19, 10/5 1999). Assuming that the internal quantum efficiency of the laser device is 5%, the lowest laser threshold reported so far is applied to 100w/cm²(Berggren et al Letters nature, vol.389, P.466, 1997, 10.2 days) and neglecting the loss mechanism mentioned above, the lower limit of the electric pumping laser threshold is 1000A/cm². Taking the loss mechanism into account, the laser threshold is far higher than 1000A/cm²This is the highest current density reported to date, supported by organic devices (Tessler, Advanced Materials, P.64, phase 1 of 10 months 1998).

One way to avoid these difficulties is to use organic crystalline materials as the medium for the laser instead of amorphous organic materials. This method has recently been adopted (Schon, Science, vol.289, 28/7/2000), in which fabry-perot resonators were fabricated using the single crystal butan province as the gain material. By using crystalline tetracos, greater current densities can be achieved, and thicker coatings can be used (since carrier mobility is about 2 cm)²V-s) and the polarized molecules absorb much less. The crystal tetracos is used as a gain material, and the room temperature laser threshold current density is about 1500A/cm²。

An alternative to electrical pumping of organic lasers is optical pumping by an incoherent light source, such as a Light Emitting Diode (LED), which may be inorganic (mcgehe et al, Applied physics letters, vol.72, No.13, 30.3.1998) or organic (Berggren et al, U.S. Pat. No.5,881,689, issued 3.9.1999). This possibility is due to the much lower emission absorption recombination losses (-0.5 cm) of the non-pumped organic laser system at the laser wavelength, especially when one uses the host-dopant combination as the lasing medium^-1). Even if benefits are obtained from these small losses, depending on the waveguide laser design (Berggren et al, Letters to nature, vol.389, 199)7 years, 10 months, 2 days), the lowest optical pumping threshold of the organic laser reported so far is 100W/cm². Because the power density provided by the existing inorganic LED is only-20W/cm at most²Different approaches must be taken to rely on incoherent light sources to facilitate optical pumping. In addition, in order to lower the lasing threshold, the gain volume of the most preferred laser mechanism must be minimized, and the standard is met by VCSEL-based micro-cavity lasers. The adoption of VCSEL-based organic laser cavity can ensure that the threshold value of optical pumping power density is less than 5W/cm². As a result, practical organic laser devices can be driven by optical pumping of various readily available incoherent light sources, such as LEDs.

Organic based gain media have some disadvantages which can be overcome if the laser system is carefully designed. Organic materials face the problem of low light and thermal damage thresholds. The pumping power density of the device should be limited to prevent irreversible damage to the device. In addition, organic materials are sensitive to various environmental factors such as oxygen and water vapor. Reducing sensitivity to these variables generally increases the useful life of the device.

One of the advantages of organic-based laser-based lasers is that, since the gain material is typically amorphous, the manufacturing cost of the device is not expensive compared to lasers requiring a gain material (organic or inorganic material) with a high degree of crystallinity. Furthermore, lasers based on organic amorphous gain materials can be fabricated in large areas without concern for producing large single crystal masses; therefore, they can be scaled to any size, resulting in a larger output power. Organic based lasers can be produced on a wide variety of substrates due to their amorphous nature, and therefore materials such as glass, soft plastic, Si are possible supports for these devices, with a significant cost advantage, and there is a wide choice of available support materials for amorphous organic based lasers.

Disclosure of Invention

The present invention is directed to overcoming one or more of the problems set forth above. Briefly, according to one aspect of the present invention, an organic laser cavity structure is described comprising:

a) a plurality of organic laser cavity devices, each organic laser cavity device characterized by:

i) a first dielectric stack that can receive and emit a pump beam and reflect a predetermined wavelength range into laser light;

ii) an organic active region capable of receiving the pump beam emitted from the first dielectric stack and emitting light;

iii) the second dielectric stack can reflect the pump beam and the laser light emitted from the organic active region and back to the organic active region, wherein the combination of the first and second dielectric stacks and the organic active region generate the laser light; and

b) the plurality of organic laser cavity devices are arranged in a predetermined manner, thereby obtaining a desired laser output, and the organic laser cavity device has various purposes.

One advantage of organic laser cavity devices is that they can be conveniently formed into arrays of individually addressable elements at low cost. In such an array, each element may be incoherent with its neighboring element and may be pumped by an independent pump source (e.g., an LED or group of LEDs). The array may be one-dimensional (linear) or two-dimensional (planar), depending on the application requirements. The elements in the array may also include multiple host-dopant combinations and/or multiple cavity structures, so that both arrays may produce multiple wavelengths. Furthermore, organic laser cavity devices can be processed into large area structures because there are no supporting requirements for single crystallinity as with typical inorganic VCSEL devices.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent when taken in conjunction with the following description and accompanying drawings wherein like parts are designated by like reference numerals where possible and wherein:

FIG. 1 is a schematic cross-sectional side view of an optically pumped organic laser cavity device;

FIG. 2 is a schematic cross-sectional side view of an optically pumped organic-based vertical cavity laser having an organic gain region with a periodic structure;

FIG. 3 is a schematic cross-sectional side view of an optically pumped two-dimensional phase-locked organic vertical cavity laser array device;

FIG. 4 illustrates an organic laser cavity structure fabricated in accordance with the present invention, wherein a one-dimensional arrangement of organic laser cavity devices is depicted;

FIG. 5 illustrates an organic laser cavity structure fabricated in accordance with the present invention, wherein a two-dimensional arrangement of organic laser cavity devices is depicted;

FIG. 6 illustrates an organic laser cavity structure fabricated in accordance with the present invention, wherein a two-dimensional substantially randomly arranged organic laser cavity device is depicted;

FIG. 7 is a schematic top view of an organic laser cavity structure made in accordance with the present invention, depicting an organic laser cavity device in a two-dimensional hexagonal arrangement;

FIG. 8 illustrates an organic laser cavity structure made in accordance with the present invention, wherein an organic laser cavity device is depicted in a two-dimensional Bayer pattern arrangement;

FIG. 9 illustrates an organic laser cavity structure fabricated in accordance with the present invention, wherein one-dimensional or linearly arranged organic laser cavity devices are depicted and the spatial relationship between the organic laser cavity devices is depicted;

FIG. 10 depicts an organic laser cavity structure in which subarrays of organic laser cavity devices of different wavelengths are combined;

FIG. 11 illustrates an organic laser cavity structure made in accordance with the present invention, wherein the structure is combined on a flexible support;

FIG. 12 illustrates an organic laser cavity structure made in accordance with the present invention in which a uniform light source illuminates the organic laser cavity with time-varying optical radiation; and

FIG. 13 depicts a method of directing light emitted from an organic laser cavity structure made in accordance with the present invention onto a target.

Detailed Description

To facilitate understanding, elements common to the figures are identified as much as possible with the same reference numeral.

In the present invention, for simplicity, the terminology describing vertical cavity organic laser devices VCSELs is used interchangeably with "organic laser cavity devices". The organic laser cavity structure is made into a large area structure and light pumping is performed by using a Light Emitting Diode (LED).

Fig. 1 shows a schematic diagram of a vertical cavity organic laser device 10. The substrate 20 may be either optically transparent or opaque depending on the optical pumping and the desired direction of laser radiation. The light transmissive substrate 20 may be transparent glass, plastic, or other transparent material, such as sapphire. Opaque substrates, on the other hand, include, but are not limited to, semiconductor materials (e.g., silicon) or ceramic materials, and may be used where both optical pumping and radiation are present on the same surface. A lower dielectric stack 30 is deposited over the substrate followed by an organic active region 40. An upper dielectric stack 50 is then deposited. The pump beam 60 optically pumps the vertical cavity organic laser device 10. The source of the pump beam 60 can be an incoherent source, such as radiation from a Light Emitting Diode (LED). Alternatively, the pump beam 60 may originate from a coherent laser source. Fig. 1 shows laser radiation 70 from the upper dielectric stack 50. Alternatively, the laser device may be optically pumped through the upper dielectric stack 50 while the laser light is emitted through the substrate 20 by appropriate design of the reflectivity of the dielectric stack. In the case of an opaque substrate, such as silicon, the optical pumping and laser radiation is able to pass through the upper dielectric stack 50.

The preferred material for organic active region 40 is a small molecular weight organic matrix-dopant combination, typically deposited by high vacuum thermal sublimation. These host-dopant combinations are advantageous because they result in very little unpumped divergence/absorption loss for the gain medium. The organic molecules are preferably small molecular weight molecules because vacuum deposited materials can be deposited more uniformly than spin-coated polymeric materials. The host material used in the present invention is preferably selected so that it absorbs the pump beam 60 well and transfers a significant portion of its excitation energy to the dopant material via Forster energy. The concept of Forster energy transfer is familiar to those skilled in the art and involves the radiationless energy transfer between the host and the dopant molecule. An example of a useful host-dopant combination for red-emitting lasers is tri-aluminum (8-hydroxyquinoline) (Alq) as the host and [4- (cyanomethylene) -2-trichlorophenol-isobutyl-6- (1, 1, 7, 7, -tetramethyljulolidine-9-eneyne) -4H-pyran-idine (DCJTB) as the dopant (volume fraction 1%). Other host-dopant combinations may be used for other wavelength emitters. For example, in the green, a useful combination is Alq as the host and [10- (2-benzothiazolyl) -2, 3, 6, 7-tetrahydro-1, 1, 7, 7-tetramethyl-1H, 5H, 11H- [1] benzopyran [6, 7, 8-ij ] quinolizin-11-one ] (C545T) as the dopant (0.5% by volume). Other organic gain materials may be polymers such as polyphenylene vinylene derivatives, dialkoxyphenylene butylenes, poly-p-phenylene derivatives, and polyfluorene derivatives, which are commonly assigned by Wolk et al and published as 27.2.2001, the contents of U.S. Pat. No.6,194,119B1, incorporated herein by reference. The purpose of the organic active region 40 is to receive the transmitted pump beam 60 and radiate the laser.

The lower and upper dielectric stacks 30 and 50, respectively, are preferably deposited from conventional electron beam deposition and comprise dielectric materials of alternating high and low refractive indices, such as TiO, respectively₂And SiO₂. Other materials, e.g. Ta for high-refractive-index layers₂O₅And may be used. The lower dielectric stack 30 is deposited at a temperature of approximately 240 c. During deposition of the upper dielectric stack 50, the temperature is maintained at about 70 ℃ to avoid melting the organic active material. In another embodiment of the present invention, the upper dielectric stack can be replaced by depositing a reflective metal mirror layer. Typical metals are silver and aluminum, with a reflection coefficient greater than 90%. In this embodiment, the pump beam 60 and the laser radiation 70 extend out through the substrate 20. The upper and lower dielectric stacks 50, 30 lase at predetermined wavelength ranges depending on the desired radiation wavelength of the laser cavity 10And (4) reflecting.

The application of high-fineness vertical microcavities allows at very low threshold values (less than 0.1W/cm)²Power density) to cause a laser transition. This low threshold makes the incoherent light source available for pumping, instead of the focused output radiation of a laser diode, which is common for other laser systems. An example of a pump light source is an ultraviolet light emitting diode UV LED, or an array of UV LEDs, available from Cree corporation (specifically XBRIGHT)^900 Ultra Violet Power Chip^An LED). These light sources emit light having a central wavelength of about 405nm and are known to produce 20W/cm in wafer form²The power density of (a). Thus, even if the limitations on the utilization are taken into account due to the large radiation distribution angle of the device package and the LED, the brightness of the LED is sufficient to reach many times the above-mentioned laser threshold to pump the laser cavity.

The active region structure of the vertical cavity organic laser device 80 shown in fig. 2 may further improve the efficiency of the laser. The organic active region 40 (shown in fig. 1) includes one or more gain regions 100 disposed in spaced apart relation and organic spacer layers 110 (see fig. 2) on either side thereof, arranged such that each gain region 100 is aligned with an antinode 103 of the device's electromagnetic field standing wave. Fig. 2 shows a laser static electromagnetic field pattern 120 within organic active region 40. Forming active region 40 as shown in fig. 2 is particularly advantageous because stimulated emission is strongest at antinode 103 and negligible at node 105 of the electromagnetic field. The organic spacer layer 110 does not undergo stimulated emission or spontaneous emission and substantially absorbs neither the laser radiation 70 wavelength nor the pump beam 60 wavelength. An example of the spacer layer 110 is 1, 1-bis- (4-bis (4-tolyl) -aminobenzene) -cyclic ethylene (TAPC), which is an organic material. TAPC is a good spacer material because it absorbs essentially neither the energy of the laser radiation 70 nor the energy of the pump beam 60, and furthermore, its refraction is slightly lower than most organic matrix materials. The difference in refractive index is useful because it helps to maximize the overlap between the anti-nodes of the electromagnetic field and the periodically configured gain region 100. As will be seen from the following discussion of the present invention, the periodically configured gain regions 100 are employed without the use of an overall gain region for higher power conversion coefficients and lower undesirable spontaneous emissions. The location of the periodically configured gain regions 100 is determined by standard matrix methods of available optics (Corzine et al, IEEE Journal of Quantum electronics, Vol.25, No.6, 6/1989). For better results, the thickness of the periodically arranged gain region 100 must be below 50nm to avoid unwanted spontaneous emission.

The use of the phase-locked organic laser array device 190 shown in fig. 3 increases the laser area while maintaining some spatial coherence. In order to form a two-dimensional phase-locked organic laser array device 190, it is necessary to fix organic laser cavity devices 200 separated by inter-pixel regions 210 on the VCSEL surface. To achieve phase lock, intensity and phase information is preferably exchanged between the organic laser cavity device 200. This can be achieved by weakly confining the laser radiation to the device region by reducing the internal refractive index or gain guide, e.g. by adjusting the reflectivity of a mirror. In a preferred embodiment, the etched regions 220 are patterned and formed in the lower dielectric stack 30 using standard photolithographic and etching techniques to effect the adjustment of reflectivity to form a two-dimensional array of cylinders 211 at the surface of the lower dielectric stack 30. The remainder of the organic laser microcavity device structure is deposited over the patterned lower dielectric stack 30 as described above. In a preferred embodiment, the laser picture elements are circular, but may also be of other shapes, such as rectangular. The spacing between the picture elements is 0.25-4 μm. The phase-locked array operation is required when the inter-pixel spacing is large, but this results in insufficient utilization of the optical pumping energy to form the etching region 220, preferably with an etching depth of 200-1000 nm. By etching into the lower dielectric stack 30 just outside the odd layers, a large shift in longitudinal mode wavelength can be made in the etched region away from the highest point of the gain medium. Thus, the laser action is hindered and the spontaneous emission is greatly reduced in the inter-pixel region 210. The net result of the formation of etched areas 220 is that the laser radiation is confined to the organic laser cavity device 200, the inter-pixel regions 210 do not lase, and the phase-locked organic laser array device 190 emits coherent phase-locked laser light.

The organic laser cavity structure is a device in which a plurality of organic laser cavity devices 200 are prearranged. Fig. 4 shows a one-dimensional organic laser cavity structure 221. The one-dimensional organic laser cavity structure has a plurality of organic laser cavity devices 200 arranged linearly. It should be appreciated that the organic laser cavity device 200, which is made up of structural parts, may have various shapes other than the circular shape, such as rectangular, triangular, etc. Fig. 4 is only an example of an organic laser cavity structure in which the arrangement of organic laser cavity devices 200 is geometrically defined. By geometric definition is meant that the pattern repeats regularly. At this time, a single organic laser cavity device 200 repeatedly appears along the length of the one-dimensional organic laser cavity structure 221.

Fig. 5 illustrates an organic laser cavity structure made in accordance with the present invention, wherein a two-dimensional arrangement of organic laser cavity devices is depicted. Such a two-dimensional organic laser cavity structure 222 is formed by assembling the organic laser cavity devices 200 in a regular two-dimensional pattern. The fabrication of these devices is familiar to those skilled in the art. The inter-pixel area 210 is typically comprised of non-lasing portions separating the structures of the respective organic laser cavity devices 200.

Applications of such one-dimensional organic laser cavity structure 221 and two-dimensional organic laser cavity structure 222 include photosensitive printing processes of lines and facets, radiation display of lines and facets, and the like. The fabrication process is used to regularly reproduce the light emitting organic laser cavity device 200 to produce an exposure apparatus for printing and display. In this configuration, the spacing of the organic laser cavity device 200 is determined by the clarity requirements of the application. For example, in a printer, the organic laser device 200 may be round, with a diameter of about 20-50 microns, and the spacing of the organic laser device 200 (inter-pixel region 210) is comparable in size. Although not illustrated, the diameter of the organic laser cavity device 200 varies across the array in one configuration, which is also considered to be one of the present invention

Embodiments are described.

Fig. 6 illustrates an organic laser cavity structure made in accordance with the present invention, wherein a two-dimensional organic laser cavity structure 223 is depicted that may be two-dimensional, substantially randomly arranged, containing an organic laser device 200 fabricated as described in fig. 1-3. The substantially random two-dimensional organic laser cavity structure 223 is preferably viewed as a random arrangement of the single organic laser cavity device 200 in a plane. Although not illustrated, a scheme in which the diameter of the organic laser cavity device 200 varies in an array in a substantially random manner is also considered an embodiment of the present invention. Such a substantially random two-dimensional organic laser cavity structure 223 has applications in a number of fields, including encryption of information and image display.

Fig. 7 is a schematic top view of an organic laser cavity structure made in accordance with the present invention, wherein an organic laser cavity device is shown in a two-dimensional hexagonal scheme. This hexagonal two-dimensional organic laser cavity mechanism 224 includes an organic laser cavity device 200 that produces the most closely spaced array in plane. The advantage of such an array is that optical radiation is output at a high power density. The high power density is obtained due to the most closely spaced nature of the hexagonal scheme. Fig. 7 shows three light emitting organic laser cavity devices 225. Other packing schemes are possible.

Fig. 8 illustrates an organic laser cavity structure made in accordance with the present invention, wherein a two-dimensional bayer pattern arrangement of organic laser cavity device 226 is depicted. This bayer two-dimensional organic laser cavity structure 226 can produce multi-wavelength optical radiation, where the laser emission is designed to produce discrete wavelengths in the red (R), green (G), and blue (B) regions of the spectrum. The red region of the spectrum corresponds approximately to the wavelength range of 600-650 nm. The green region of the spectrum corresponds to the wavelength range of 500-550nm, and the blue region of the spectrum corresponds to the wavelength range of 450-500 nm. When the organic laser cavity device 200 is properly designed, the wavelength of the optical radiation can be in the entire visible spectral range (about 450 nm and 700 nm). It should be appreciated that pump beams of different wavelengths may be used to generate output radiation of substantially a single wavelength. This can be accomplished by proper design of the materials and thicknesses of lower dielectric stack 30 and upper dielectric stack 50, selection of the material for organic active region 40, and the dimensions of organic laser cavity device 200. Alternatively, a single wavelength of the pump beam may produce a plurality of substantially different wavelengths of output radiation. Furthermore, it can be realized by designing various organic laser cavity devices 200 in this structure. It should also be appreciated that any of the organic laser cavity structures can be designed and engineered to produce multi-wavelength optical radiation suitable for current use. In the case of a bayer two-dimensional organic laser cavity structure 226, the ratio of the green radiation channel to the red and blue radiation channels is 2: 1. This configuration is advantageous for applications requiring direct one-to-one illumination of the pixels of a photodetector array of standard CDD. The bayer structure is typically applied to a color filter array to provide color filter sensitivity for CDD and CMOS photodetectors (not shown).

Fig. 9 illustrates an organic laser cavity structure made in accordance with the present invention, wherein a one-dimensional or linear arrangement of organic laser cavity devices 200 is depicted and the spatial relationship between the various organic laser cavity devices 200 is illustrated. The spatial relationship is defined as d, the diameter of the organic laser cavity device 200, and l, the center-to-center distance between the organic laser cavity devices 200. These two parameters can be used to control the radiation characteristics of the laser output. For example, for an organic laser cavity structure consisting of organic laser cavity devices 200 intended to have substantially the same wavelength output, the phase locking of the organic laser cavity device 200 is particularly dependent on the parameters d and l. A preferred embodiment for generating a phase locked laser output has a d of 3-5 μm and a l of 3.25-9 μm. As described above, if the pitch of the organic laser cavity devices 200 is large, the area between the organic laser cavity devices 200 increases, which results in a loss of phase locking and a reduction in the light radiation utilization rate. The main advantage of this phase lock is that it causes a coherent superposition of the optical energy of the individual organic laser cavity devices. This improves the output power of the organic laser cavity structure. In some applications it is desirable to have complete incoherence between the organic laser cavity devices 200, each organic laser cavity device 200 acting as a separate laser. In this way, the laser radiation from the organic laser cavity device 200 can be made out of phase. In this case, l > 9 μm and d 3-5 μm can be used to make each organic laser cavity device 200 uncorrelated. Of course, it should be understood that many other combinations of these parameters can produce the desired output. Also, the adjustment of the coherence between the units of such an organic laser cavity structure is not limited to a one-dimensional structure well known to those skilled in the art. An organic laser cavity structure in which a larger array of cells produces phase-locked laser output substructures, each of which is independent of the other, is also an embodiment of the present invention. This arrangement facilitates simultaneous modification of the output organic laser cavity structure, optimizing optical power and resolution for various applications. Furthermore, although a circular organic laser cavity device 200 is depicted in fig. 9, other shapes are possible and may be advantageous in some applications. For example, Vertical-Cavity Surface-Emitting Lasers (Vertical Cavity Surface-Emitting Lasers) book by Wilmsen et al (cambridge university press, 2001) states that a rectangular organic laser Cavity device 200 of suitable dimensions can be used to generate polarized laser radiation from an organic laser Cavity structure.

The organic laser cavity structure described in fig. 10 incorporates sub-structures of organic laser cavity devices of different wavelengths. Such a multi-wavelength organic laser cavity structure 227 has a 3 × 3 sub-structure (not shown) with red (r), green (g), and blue (b) light regions. As previously mentioned, whether these substructures are phase locked to each other or not depends on the application requirements. Phase lock can be controlled by varying the distance parameter shown in fig. 9.

Fig. 11 illustrates an organic laser cavity structure made in accordance with the present invention, which is mounted on a flexible substrate, and which can be made flexible because of the less stringent substrate requirements of the organic laser cavity, as described above. Such a flexible organic laser cavity structure 228 has the advantage that it is lightweight and can be made to conform to a variety of uneven surfaces. Furthermore, the spatial relationship between the individual organic laser cavity devices 200 can be varied by creating the devices on a flexible substrate. Thus, the spatial relationship of the organic laser cavities can be changed. The stretched flexible matrix may be used to change the coherence length of the organic laser cavity device 200. It should be appreciated that any of the features of the organic laser cavity structure (multi-wavelength, cell coherence control, etc.) may be implemented by combination with the flexible organic laser cavity structure 228.

Fig. 12 illustrates an organic laser cavity structure made in accordance with the present invention. Wherein a light source 229, such as a plurality of light emitting diodes, illuminates the organic laser cavity structure with a time dependent light output. Bright light 230 impinges on the organic laser cavity structure 231 to optically excite the laser cavity. This time dependent organic laser cavity structure 231 can be implemented in a number of ways. In this example, the bright light 230 optically pumps a rotating time-dependent organic optical cavity structure 231. The organic laser cavity structure is configured to have an organic laser cavity device 200 that is distributed non-uniformly over the surface of the substrate. The rotation of the organic laser cavity structure 231 produces a time-independent output radiation. Also, the fixed organic laser cavity structure 231 can be optically pumped by a time varying non-uniform light source, and can also generate such output radiation.

In addition, the light source 229 may include a single wavelength pump beam that generates substantially single wavelength laser radiation; or pump beams of substantially different wavelengths that produce a single wavelength of laser radiation; or a plurality of substantially different wavelength pump beams that produce substantially different wavelength radiation.

Fig. 13 illustrates in a block diagram a method by which light can be emitted from a photon source that pumps light onto an organic laser cavity structure and directs the laser radiation onto a target. Light is generated in step 232 by means of a means providing a photo-excited organic laser cavity structure. A variety of possible light sources can be used to pump the organic laser cavity structure; this is due to the low power threshold of the laser light emitted from the organic laser cavity device 200. For example, an array of light emitting diodes (inorganic or organic) may be used for this capacity. The light impinges on the organic laser cavity structure in step 233. There are various ways to emit and influence the pump light, e.g. lenses and mirrors may be used. These optical devices are referred to as active or passive lenses, and filters and mirrors are examples of passive optical elements. They can be used to change the spatial distribution, intensity, polarization, etc. of the pump light. The active optical elements include various optical modulators (electro-optic, acousto-optic) that can be used to vary the intensity, exposure time, polarization, or spatial distribution of the incident pump light. The organic laser cavity structure described in step 234 receives pump light and generates laser light in response to incident pump light. The proper manner of laser light input from step 234 is dictated by the characteristics of the organic laser cavity structure as described in the embodiments above. The laser light generated in step 234 is directed to the target using the components in step 235. As in step 233, these components may include lenses, mirrors, modulators, etc. that are used to alter the intensity, exposure time, polarization, and spatial distribution of the laser light. Additionally, the phase of the light emitted by the organic laser cavity structure in step 234 may be modulated to affect the phase of the output beam directed to the target. Step 235 provides a means for directing and controlling the output radiation of the organic laser cavity structure to its intended target. The output radiation of the organic laser cavity structure may comprise both single and multiple wavelengths of optical radiation. Step 236 includes various forms of the target itself. These objects may include objects such as photosensitive materials, receivers or detectors for optical radiation-based communications; or for marking on the object, for scanning the object to obtain its spatial dimensions, for obtaining spatially encoded information for identification, or for location on the object for spectral analysis of the object. The photosensitive material may include a photographic material or an electrophotographic material for ablating a receiving layer of pigment or other material on the receiving material.

An organic laser cavity structure wherein the desired laser output comprises laser output from each device of the organic laser cavity having a different phase.

An organic laser cavity structure, wherein the desired laser output comprises laser output of each organic laser cavity device having substantially the same phase.

An organic laser cavity structure, wherein the desired laser output comprises laser output of each organic laser cavity device having substantially the same polarization.

An organic laser cavity structure, wherein the desired laser output comprises laser output of respective organic laser cavity devices of substantially different polarizations.

An organic laser cavity structure, wherein the predetermined arrangement is a combination of a geometrical arrangement, a phase arrangement, a wavelength arrangement, a polarization arrangement and a spatial arrangement.

An organic laser cavity structure, wherein the predetermined arrangement is planar.

An organic laser cavity structure, wherein the predetermined arrangement is non-planar.

An organic laser cavity structure in which a single wavelength pump beam produces outputs of substantially different wavelengths.

An organic laser cavity structure in which a single wavelength pump beam generates substantially single wavelength laser output.

An organic laser cavity structure in which substantially different wavelength pump beams produce a single wavelength laser output.

An organic laser cavity structure in which substantially different wavelength pump beams produce a plurality of substantially different wavelength outputs.

Organic laser cavity structures in which the required laser output is time dependent with the pump beam.

An organic laser cavity structure wherein the spatial relationship between the organic laser cavity devices varies.

An organic laser cavity structure wherein a predetermined arrangement is formed on a flexible substrate.

A method of directing optical radiation to a specific target location, comprising the steps of:

a) there is provided an organic laser cavity structure, the structure comprising: a plurality of organic laser cavity devices arranged in one or more dimensions in a layout, each organic laser cavity device being characterized by a first dielectric stack for receiving and transmitting a pump beam and reflecting into laser light over a predetermined wavelength range; the organic active region is used for receiving the pumping light beam transmitted from the first dielectric lamination layer and emitting laser; the second dielectric stack is used for reflecting the pumping light beam and the laser light transmitted from the organic active region back to the organic active region, wherein the combination of the first dielectric stack and the second dielectric stack with the organic active region generates the laser light; and a plurality of organic laser cavity devices arranged in a predetermined arrangement so as to obtain a desired optical radiation; and

b) the desired optical radiation is directed to a specific target location.

A method of directing optical radiation to a specific target location, wherein directing the optical radiation at the specific location comprises marking on an object.

A method of directing optical radiation to a specific target location, further comprising exposing a photosensitive material.

A method of directing optical radiation to a specific target location, further comprising the step of effecting optical radiation-based communication.

A method of directing optical radiation to a specific target location includes scanning an object to obtain its spatial dimensions.

A method of directing optical radiation to a specific target location includes performing spectral analysis on an object.

A method of directing optical radiation to a specific target location includes encoding information for authentication.

A method of directing optical radiation to a specific target location, comprising the steps of:

a) there is provided an organic laser cavity structure, the structure comprising: a plurality of organic laser cavity devices arranged in one or more dimensions in a layout, each organic laser cavity device being characterized by a first dielectric stack for receiving and transmitting a pump beam and reflecting into laser light over a predetermined wavelength range; the organic active region is used for receiving the pumping light beam transmitted from the first dielectric lamination layer and emitting laser; the second dielectric stack is used for reflecting the pumping light beam and the laser light transmitted from the organic active region back to the organic active region, wherein the combination of the first dielectric stack and the second dielectric stack with the organic active region generates the laser light; and a plurality of organic laser cavity devices arranged in a predetermined arrangement so as to obtain a desired optical radiation at multiple wavelengths; and

b) the desired optical radiation having multiple wavelengths is directed to a specific target location.

A method of directing optical radiation to a specific target location, wherein directing optical radiation to the specific target location comprises marking on an object.

A method of directing optical radiation to a specific target location, further comprising exposing a photosensitive material.

A method of directing optical radiation to a specific target location, further comprising the step of effecting optical radiation-based communication.

A method of directing optical radiation to a specific target location includes scanning an object to obtain its spatial dimensions.

A method of directing optical radiation to a specific target location includes performing spectral analysis on an object.

Methods of directing optical radiation to specific target locations include for encoding information for authentication.

A method of directing optical radiation to a specific target location, comprising the steps of:

a) there is provided an organic laser cavity structure, the structure comprising: a plurality of organic laser cavity devices arranged in one or more dimensions in a layout, each organic laser cavity device being characterized by a first dielectric stack for receiving and transmitting a pump beam and reflecting or lasing light over a predetermined wavelength range; the organic active region is used for receiving the pumping light beam transmitted from the first dielectric lamination layer and emitting laser; the second dielectric stack is used for reflecting the pumping light beam and the laser light transmitted from the organic active region back to the organic active region, wherein the combination of the first dielectric stack and the second dielectric stack with the organic active region generates the laser light; and a plurality of organic active cavity devices arranged in a predetermined arrangement to obtain a plurality of desired optical radiations of different phases; and

b) a desired optical radiation having a plurality of different phases is directed to a specific target location.

A method of directing optical radiation to a specific target location, wherein directing optical radiation to the specific target location comprises marking on an object.

A method of directing optical radiation to a specific target location, further comprising exposing a photosensitive material.

A method of directing optical radiation to a specific target location further comprises the step of effecting optical radiation-based communication.

A method of directing optical radiation to a specific target location includes scanning an object to obtain its spatial dimensions.

A method of directing optical radiation to a specific target location includes performing spectral analysis on an object.

A method of directing optical radiation at a specific location includes encoding information for authentication.

A method of directing optical radiation to a specific target location, comprising the steps of:

a) there is provided an organic laser cavity structure, the structure comprising: a plurality of organic laser cavity devices arranged in one or more dimensions in a layout, the devices being spaced apart in varying spatial relationships, each organic laser cavity device being characterised by a first dielectric stack for receiving and transmitting a pump beam and reflecting it into laser light over a predetermined wavelength range; the organic active region is used for receiving the pumping light beam transmitted from the first dielectric lamination layer and emitting laser; a second dielectric stack for reflecting the pump beam and laser light from the organic active region back to the organic active region, wherein the first and second dielectric stacks in combination with the organic active region produce laser light; and a plurality of organic active cavity devices arranged in a predetermined arrangement to obtain a desired optical radiation; and

b) the desired optical radiation is directed to a specific target location.

A method of directing optical radiation to a specific target location, wherein directing optical radiation to the specific target location comprises marking on an object.

A method of directing optical radiation to a specific target location, further comprising exposing a photosensitive material.

A method of directing optical radiation to a specific target location, further comprising the step of effecting optical radiation-based communication.

A method of directing optical radiation to a specific target location includes scanning an object to obtain its spatial dimensions.

A method of directing optical radiation to a specific target location includes performing spectral analysis on an object.

A method of directing optical radiation to a specific target location includes encoding information for authentication.

A method of directing optical radiation to a specific target location, comprising the steps of:

a) providing an organic laser cavity structure comprising: a plurality of organic laser cavity devices arranged in one or more dimensions in a layout, each organic laser cavity device being characterized by a first dielectric stack for receiving and transmitting a pump beam and reflecting into laser light over a predetermined wavelength range; an organic active region for receiving a pump beam from the first dielectric stack; the second dielectric stack is used for reflecting the pumping light beam and the laser light transmitted from the organic active region back to the organic active region, wherein the combination of the first dielectric stack and the second dielectric stack with the organic active region generates the laser light; and a plurality of organic laser cavity devices arranged in a predetermined arrangement so as to obtain a desired optical radiation; and

b) by selectively exciting one or more organic laser cavity devices, the desired optical radiation is directed to a specific target location.

A method of directing optical radiation to a specific target location, wherein directing optical radiation to the specific target location comprises marking on an object.

A method of directing optical radiation to a specific target location, further comprising exposing a photosensitive material.

A method of directing optical radiation to a specific target location, further comprising the step of effecting optical radiation-based communication.

A method of directing optical radiation to a specific target location includes scanning an object to obtain its spatial dimensions.

A method of directing optical radiation to a specific target location includes performing spectral analysis on an object.

A method of directing optical radiation to a specific target location includes encoding information for authentication.

Claims (12)

1. An organic laser cavity structure comprising

a) A plurality of organic laser cavity devices, each organic laser cavity device characterized by:

i) a first dielectric stack for receiving and transmitting the pump beam and reflecting into laser light over a predetermined wavelength range;

ii) an organic active region for receiving the pump beam from the first dielectric stack and emitting laser light;

iii) a second dielectric stack for reflecting the pump beam and laser light propagating from the organic active region back to the organic active region, wherein the combination of the first and second dielectric stacks and the organic active region produces laser light; and

b) a plurality of organic laser cavity devices are arranged in a predetermined arrangement so that a desired laser output can be obtained.

2. An organic laser cavity structure as claimed in claim 1, wherein the arrangement is geometrically defined.

3. An organic laser cavity structure as claimed in claim 2, wherein the arrangement is a linear arrangement.

4. An organic laser cavity structure as claimed in claim 2, wherein the arrangement is a two-dimensional arrangement.

5. An organic laser cavity structure as claimed in claim 2, wherein the arrangement is substantially random.

6. An organic laser cavity structure as claimed in claim 2, wherein the arrangement is a hexagonal two-dimensional arrangement.

7. An organic laser cavity structure as claimed in claim 2, wherein the arrangement is a bayer pattern arrangement.

8. An organic laser cavity structure as defined in claim 1, wherein the arrangement is defined by a spatial relationship between the plurality of organic laser cavity devices.

9. An organic laser cavity structure as defined in claim 8, wherein the spatial relationship is fixed.

10. An organic laser cavity structure as defined in claim 8, wherein the spatial relationship is variable.

11. An organic laser cavity structure as claimed in claim 1, wherein the desired laser output comprises different laser radiation wavelengths originating from a plurality of organic laser cavity devices.

12. An organic laser cavity structure as defined in claim 1, wherein the desired laser output comprises substantially the same wavelength of laser radiation originating from a plurality of organic laser cavity devices.