DE102023128400A1 - Housing with laser arrangement and method for producing a housing with laser arrangement - Google Patents

Abstract

The invention relates to a housing with a laser arrangement, comprising a cover that encompasses a partial region transparent to laser radiation, and three substrates. Each substrate has at least one edge-emitting laser ridge designed as a resonator with an output facet for emitting laser radiation of one wavelength, wherein the wavelengths of the laser ridges are different. At least one of the first, second, and third substrates comprises at least one mirror element for deflecting the laser radiation emitted by the corresponding edge-emitting laser ridge toward the transparent partial region. In addition, each of the three substrates has a side surface that is adjacent to or coincides with the respective output facet, and the side surfaces of two of the three substrates are at least partially adjacent to one another and opposite one another.

Description

The invention relates to a housing with a laser arrangement and a method for producing such a housing with a laser arrangement.

BACKGROUND

Laser arrays are used, among other things, to generate red, green, and blue light for projection applications. In addition to traditional projectors, these include so-called "near-eye" applications, such as those used in AR or VR headsets. Lasers of different colors are also used in the automotive sector or in special displays. The use of lasers enables high luminance to be concentrated in a small space, thereby creating a bright image for the user using additional downstream optical systems. Lasers with different wavelengths are now also available, allowing all colors, including various shades of white, to be easily produced.

However, it has been discovered that the resulting heat generated during laser diode operation can pose a problem when generating high luminance, as it must be dissipated quickly enough. Furthermore, conventional setups require complex optics to superimpose the laser beams onto a common point to create mixed light or white laser light and then direct it onto the projection surface. If even a slight misalignment occurs between the individual laser light beams, this becomes apparent as a "fraying" of the mixed light, i.e., the individual colors are visible, particularly at the edges.

For this reason, it is often suggested to process multiple laser beams in such a way that they have the smallest possible combined output area. This approximately point-like light source has the advantage that downstream optics, such as lenses or piezoelectric mirrors and other elements, can be designed more simply. By superimposing the individual laser beams, such an approximately point-like light source is possible. The area in which the output facets of a combination of red, blue and green laser diodes should preferably be located should not exceed 250µm x 250µm and in some applications can be even smaller. This usually means that the necessary optical systems have to be provided by lenses and beam combiners, depending on the implementation, and thus complex active adjustment is required. Such complex optical systems are rather cumbersome, especially in compact and small projection applications.

Alternatively, it has been suggested that the individual laser elements be spatially arranged in such a way as to achieve the smallest possible output coupling area. For example, the output facets of various lasers placed close to one another should lie within an area of 200 µm by 250 µm or even less. This also allows other optical systems to be kept simple and small. However, bringing edge-emitting lasers together in very small areas, for example of a few 100 µm, is difficult and, in part, almost impossible due to the design of the respective lasers. Secondly, the position of the laser ridges and the dimensions of the laser substrates restrict positioning.

Accordingly, it is an object of the invention to provide housings with laser arrangements that mitigate or overcome at least some of the above-mentioned disadvantages.

SUMMARY OF THE INVENTION

This need is addressed by the subject matter of the independent patent claims. Further developments and embodiments of the proposed principle are specified in the subclaims. The inventors propose the use of so-called bottom-emitting laser diodes, which, combined with a suitable package concept, realize a small output area using established assembly processes.

Bottom-emitting laser diodes are lasers that also have an edge-emitting resonator, but also a mirror element integrated into the substrate of the laser, so that the laser beam is emitted perpendicular to the laser ridge.

The proposed concept allows for the provision of a compact and small output area for several such laser diodes of the same or different colors. Furthermore, the proposed principle allows the use of substrates with two or more edge-emitting laser ridges, so-called "multi-ridge lasers," which are advantageous in many applications due to the individual control of each ridge.

According to the proposed principle, in some aspects, a housing with a laser arrangement comprises a lid which has a laser radiation transparent subregion. The transparent subregion can be made of SiO2, for example. To achieve better heat dissipation, it is possible to construct the cover from a material combination, for example, of SiO2 and metal, SiO2 and ceramic, or even SiO2 and semiconductor, with only the transparent subregion being formed from SiO2. This improves heat dissipation from the cover in some embodiments. Instead of SiO2, another material that is transparent to the respective laser beams can also be used for the subregion.

The housing with laser arrangement comprises a first substrate, a second substrate, and optionally a third substrate. Each of the substrates comprises at least one edge-emitting laser ridge designed as a resonator with an output facet for emitting laser beams. The first substrate with the first edge-emitting laser ridge designed as a resonator is designed to emit laser radiation of a first wavelength. The second substrate with the second edge-emitting laser ridge designed as a resonator is designed to emit laser radiation of a second wavelength, and the third substrate is designed to emit laser radiation of a third wavelength. In this context, the substrates can comprise different materials for generating laser radiation with the different wavelengths. In an alternative embodiment, the respective substrates with the edge-emitting laser ridge designed as a resonator can also be designed to emit light of the same wavelength. This allows very high luminance levels to be achieved, which are important, for example, for laser drilling or welding systems.

According to the proposed principle, at least one of the first, second, and third substrates is designed with a mirror element for deflecting the laser radiation emitted by the corresponding edge-emitting laser ridge. The mirror element is arranged such that it deflects the emitted laser radiation toward the transparent subregion. Each of the three substrates further comprises a side surface that is adjacent to the respective output facet or, in some aspects, even coincides with it. The side surfaces of two of the three substrates are arranged at least partially adjacent to one another and opposite one another.

This ensures a particularly compact and space-saving implementation, with the at least one bottom emitter achieving a common output surface that is significantly smaller than conventional arrangements. In particular, output surfaces smaller than 50 µm x 250 µm can be achieved, although this is essentially limited by the design of the individual substrates. The output surface can be viewed as an approximately point-shaped light source for both lasers with a single laser ridge (“single ridge” laser) and lasers with multiple laser ridges (“multi ridge” laser). This simplifies the optical systems downstream in the beam path and, in particular, makes it possible to dispense with beam combiners, since the very small output surface already achieves almost complete superposition of the individual emitted laser beams.

In this context, a bottom side of the substrate is defined as the side on which the edge-emitting laser ridge is located. The side of the substrate opposite the edge-emitting laser ridge is defined as the top side of the substrate. Both sides contain contacts or contact surfaces designed to individually control the laser ridges. The contact surfaces are, for example, metallized surfaces.

The substrates can be formed with different material systems in some aspects. For example, phosphide or arsenide material systems, such as GaP, InGP, AlGaP, InAlGaP, or even GaAs and AlGaAs, are used to generate red laser light. The precise wavelength can be adjusted by the indium content. Nitride-based material systems are used to generate green or blue laser light. Examples include GaN, AlGaN, InGaN, and InAlGaN.

Due to the different material systems, the resonators forming the laser ridges can be designed with different lengths, resulting in substrates of varying lengths. Overall, it is advisable to design the resonators as short as possible, depending on the desired requirements, in order to achieve the most compact design possible for the housing containing the laser array.

The substrates can be designed as single-ridge lasers or as multi-ridge lasers, with each individual laser ridge being separately and individually controllable. This allows the light output of the laser radiation generated by the respective substrate to be adjusted over a wide range.

In some aspects, at least a second of the first, second and third substrates also includes a mirror element for deflecting the laser radiation emitted by the corresponding edge-emitting laser ridge toward the transparent subregion. Alternatively, all substrates can each have a mirror element for deflecting the laser radiation emitted by the corresponding edge-emitting laser ridge toward the transparent subregion. In this embodiment, all substrates would then be designed as bottom-emitting lasers.

When using multiple laser ridges per substrate, each laser ridge can be assigned such a mirror element. Alternatively, it is also possible to provide a common mirror element for all laser ridges in the respective substrate. In some embodiments, the mirror element can have a recess in the respective substrate, wherein one side surface of the recess forms the respective output facet of the edge-emitting laser ridge and an opposite reflective side surface is arranged obliquely with respect to the respective output facet. This angle can be 45°, for example, and can be etched into the substrate depending on the material. This enables a particularly space-saving deflection of the laser light emitted by the laser ridge perpendicular to the underside of the substrate. In some aspects, the mirror element for deflecting the laser radiation emitted by the corresponding edge-emitting laser ridge is laterally spaced from the side surface of the respective substrate. This distance is expediently designed to be as small as possible in order to arrange the respective substrates as close to one another as possible.

In some aspects, the substrates with the mirror elements are attached to the cover, in particular via appropriate metallization, so that the mirror elements are arranged directly opposite the transparent portion. For example, the substrates can be soldered onto the cover accordingly. With a suitable design of the cover, for example a glass-ceramic or glass-metal joint, the substrates can be soldered in the ceramic or metallic area, thus also achieving very good heat conduction between the cover and the respective substrates. This not only enables a very compact output surface but also sufficient heat dissipation during operation of the respective laser burrs.

The substrates are attached to the lid with their respective undersides, for example by a structured metallization using a gold-tin connection. By attaching the substrates directly to the lid with the mirror elements opposite the transparent partial area or the output facet opposite the transparent partial area, the distance between the respective mirror element or the output facet and the transparent partial area is very small. This advantageously suppresses an optical tweezer effect. At the same time, the metallization can serve as a contact for the electrical connection to the at least one laser ridge. A further connection can be present, for example, on the top side of the respective substrate and can be led to another contact on the lid by means of a wire connection.

In one aspect, the housing further comprises a frame which is connected to the cover to form a particularly hermetically sealed receiving space. In some aspects, the hermetic sealing is achieved via a metal connection. The first, second and third substrates are arranged in the receiving space. In this exemplary embodiment, in contrast to conventional concepts, at least one substrate is fastened to the cover. This makes it possible to design the receiving space as compactly as possible, with the dimensioning being essentially determined by the existing wire connection between the substrate and the contact region on the cover. Overall, particularly flat housings with laser arrangements can be realized by connecting the substrates to the cover.

In some aspects, the housing further comprises a number of contact surfaces. Depending on the implementation, these can be arranged on the outside of the cover, for example, around the transparent portion. In an alternative embodiment, the frame can be configured with a plurality of conductive feedthroughs to provide contact surfaces on the outside, i.e., the side facing away from a receiving space. In this case, the frame or the base plate of the frame serves as a support surface for SMD assembly in the respective applications.

Through feedthroughs, signals are transmitted from the outer contact surfaces of the base plate into the receiving space and from there via wire connections or other means to the laser ridges of the various substrates. In another embodiment, in which the contact surfaces are located on the outside of the cover, conductive feedthroughs are also provided through the cover. This minimizes the electrical path length, which leads to improved fast switching due to the lower impedance and lower electrical resistance. In addition, the frame can be designed more simply, as it only provides mechanical protection for the substrates and does not provide any connections. This also eliminates higher quality requirements. the surface of the frame. The contact in the cover also allows for thermal heat dissipation through the cover, or rather, this can be improved compared to other concepts.

In this context, in some aspects, the cover also comprises, in addition to the transparent portion, a material surrounding the transparent portion that has a higher thermal conductivity. This material is, for example, a metal, a semiconductor material, a ceramic, or combinations thereof. Accordingly, in some aspects, it is provided that the substrates are attached by their undersides to the ceramic or metallic parts of the cover.

Some aspects deal with the geometric arrangement of the different substrates among each other.

In one aspect, two of the three substrates can be arranged side by side with output facets pointing in the same direction. The third of the three substrates is arranged opposite these with the output facet. If there are more substrates, they can be arranged opposite each other in pairs. Depending on the design, the at least three substrates can be attached either jointly to the cover or jointly to a base plate of the frame. Alternatively, triangular arrangements are also conceivable.

In another aspect, however, one of the three substrates is tilted relative to the other two substrates, specifically arranged at 90° to the other two substrates. This results in at least one of the substrates being configured as an edge-emitting laser arrangement, in which the output facet simultaneously also forms part of the side edge of the substrate. In other words, in this embodiment, no mirror element for generating a bottom-emitting laser diode is present in the at least one substrate.

In some aspects, two of the three substrates are configured either with edge-emitting output facets without a mirror element or with respective mirror elements to create a bottom-emitting laser diode. The ratio of bottom-emitting laser diode to edge-emitting diode in the proposed arrangement is either 2:1 or 1:2. In an arrangement with only two substrates, one substrate can be configured with an edge-emitting output facet without a mirror element, and the other substrate with a mirror element. In a further embodiment, more than three laser diodes or substrates can be used.

For example, one or two of the substrates can be arranged on the cover and two or one substrate perpendicular to the cover on a side wall of the housing. Alternatively, it is also possible to arrange the three substrates on a common metallized submount, with their respective output facets located close to a corner or edge of this submount. In particular, it is possible to bring the output facets or the mirror elements of the substrates very close together due to the arrangement close to the edge in order to thus create a common, very small coupling-out area. In one embodiment, a cuboid body is provided as the submount, with the individual substrates arranged along common side edges and at a common corner.

Such a configuration has the advantage that a mirror element does not have to be present for all substrates. Rather, this arrangement allows a very small coupling-out area to be realized even when using additional conventional components. In particular, it is possible, for example, to arrange the substrates along a corner of a cube on the various side surfaces. This also advantageously allows a package to be realized in which there are two coupling-out surfaces whose distance corresponds to the side length of such a cube. The submount can be optimized for thermal cooling of the substrates during operation.

In embodiments in which the substrates are tilted relative to one another, it is expedient in some embodiments for at least one of the three substrates to be formed with at least one edge-emitting laser ridge configured as a resonator; and for at least one of the three substrates to be formed with at least one first edge-emitting laser ridge configured as a resonator, at the output facet of which a mirror element is arranged within the substrate for deflecting the laser radiation emitted by the corresponding edge-emitting laser ridge toward the transparent subregion. In other words, in these embodiments, at least two of the three substrates are different, i.e., designed as edge-emitting and bottom-emitting laser arrangements.

In a further aspect, the housing comprises at least one submount, on which at least one of the three substrates with the at least one edge-emitting laser ridge configured as a resonator is arranged. In some embodiments, the submount is formed from separate partial surfaces that are assembled together. The separate partial surfaces can each have The submounts can include two substrates configured as edge-emitting and bottom-emitting laser arrays. This allows the sub-areas to be manufactured separately and then assembled so that three substrates are arranged in a common corner of the submount.

A further aspect relates to a method for producing a housing with a laser arrangement according to the proposed principle.

In the method, a cover with a transparent portion is first provided. The cover can be formed from a ceramic substrate, a semiconductor substrate, or even a metallic substrate, which surrounds the transparent portion, for example, made of glass. The non-transparent portion has a higher thermal conductivity.

Then, on an underside of the cover, i.e., a side of the cover that will later face into the housing, a first substrate with at least one first edge-emitting laser ridge configured as a resonator and having an output facet for emitting laser radiation is arranged. This can be done on the non-transparent part. This is done in such a way that the edge-emitting laser ridge faces the cover, and the first substrate comprises a mirror element for deflecting the laser radiation emitted by the corresponding edge-emitting laser ridge toward the transparent portion. The first substrate is attached to the cover, for example, via a solder connection.

Subsequently, a further substrate is provided, which is also configured with an edge-emitting laser arrangement. The further substrate is arranged such that a side edge of the at least one further substrate adjacent to an output facet of the laser arrangement is adjacent to a side edge of the first substrate adjacent to the mirror element.

Depending on the design, this can be achieved, for example, by attaching the at least one additional substrate to the cover. In this case, the at least one additional substrate would also be implemented with a mirror element, similar to the first substrate. If the at least one additional substrate is implemented with an edge-emitting laser whose output facet, without a mirror element, is parallel to the side flank of the substrate, it is expedient to arrange the at least one additional substrate tilted relative to the first substrate.

In a final step, the lid is attached to a frame with base plates to form a receiving space, so that the substrates are arranged in the receiving space.

In a further aspect, the at least one further substrate comprises a mirror element for deflecting the laser radiation emitted by the corresponding edge-emitting laser ridge toward the transparent partial region. It is arranged on the cover such that the side edge of the further substrate adjacent to the mirror element is opposite the side edge of the first substrate.

In the case of tilting, the at least one additional substrate can be tilted, in particular by 90°. It can also be arranged on a suitable submount located in the receiving space of the housing. Alternatively, the additional substrate can also be arranged and secured to the frame.

In another aspect, the lid is provided with a metallization serving as a contact, wherein the metallization is in electrical connection with the edge-emitting laser ridge. In some aspects, the metallization may be electrically connected to a feedthrough in the frame, wherein the feedthrough in the frame leads to a bottom side of the base plate. In other aspects, the lid comprises one or more feedthroughs connected to the metallization and leading to contact pads on a top side of the lid. Combinations thereof are also possible.

BRIEF DESCRIPTION OF THE DRAWINGS

• 1 zeigt eine Laseranordnung in Seitendarstellung nach einigen Aspekten des vorgeschlagenen Prinzips;
• 2 stellt die Unterseite der Laseranordnung Nach der Ausgestaltung in 1 dar;
• 3 zeigt in Draufsicht auf einen transparenten Deckel eine Ausgestaltung eines Gehäuses mit Laseranordnung nach dem vorgeschlagenen Prinzip;
• 4 ist eine Seitendarstellung der Ausgestaltung des Gehäuses mit Laseranordnung nach dem vorgeschlagenen Prinzip nach der vorangegangenen Figur.
• 5 zeigt eine Seitendarstellung einer leicht abgewandelten Ausgestaltung eines Gehäuses mit Laseranordnung gemäß einigen Aspekten ds vorgeschlagenen Prinzips;
• 6 stellt eine Draufsicht einer weiteren Ausgestaltung eines Gehäuses mit Laseranordnung nach einigen Aspekten des vorgeschlagenen Prinzips dar;
• 7 zeigt die korrespondierende Seitenansicht der Ausgestaltung nach 6;
• 8 zeigt in Seitendarstellung eine weitere Ausgestaltung eines Gehäuses mit Laseranordnung nach einigen Aspekten des vorgeschlagenen Prinzips;
• 9 stellt eine weitere Ausgestaltung eines Gehäuses mit Laseranordnung nach einigen Aspekten des vorgeschlagenen Prinzips dar;
• 10 zeigt in perspektivische Darstellung einer weiteren Ausgestaltung eines Gehäuses mit Laseranordnung nach einigen Aspekten des vorgeschlagenen Prinzips;
• 11 ist eine Seitendarstellung einer Ausführung der 8 in einem Gehäuse nach einigen Aspekten des vorgeschlagenen Prinzips;
• 12 zeigt eine Abwandlung einer Ausgestaltung wie in 9 mit einigen Aspekten des vorgeschlagenen Prinzips;
• 13A und 13B zeigen eine Ausgestaltung eines Gehäuses als Seitenemitter nach einigen Aspekten des vorgeschlagenen Prinzips;
• 14 ist eine Ausgestaltung eines Verfahrens zur Herstellung eines Gehäuses mit Laseranordnungen nach einigen Aspekten des vorgeschlagenen Prinzips.

Further aspects and embodiments according to the proposed principle will become apparent with reference to the various embodiments and examples which will be described in detail in conjunction with the accompanying drawings.

• 1 shows a laser arrangement in side view according to some aspects of the proposed principle;
• 2 represents the underside of the laser arrangement. After the design in 1 represents;
• 3 shows a top view of a transparent cover of a housing with a laser arrangement according to the proposed principle;
• 4 is a side view of the design of the housing with laser arrangement according to the proposed principle according to the previous figure.
• 5 shows a side view of a slightly modified design of a housing with laser arrangement according to some aspects of the proposed principle;
• 6 shows a plan view of a further embodiment of a housing with laser arrangement according to some aspects of the proposed principle;
• 7 shows the corresponding side view of the design according to 6 ;
• 8 shows a side view of a further embodiment of a housing with a laser arrangement according to some aspects of the proposed principle;
• 9 shows a further embodiment of a housing with a laser arrangement according to some aspects of the proposed principle;
• 10 shows a perspective view of a further embodiment of a housing with a laser arrangement according to some aspects of the proposed principle;
• 11 is a side view of a version of the 8 in a housing according to some aspects of the proposed principle;
• 12 shows a modification of a design as in 9 with some aspects of the proposed principle;
• 13A and 13B show a design of a housing as a side emitter according to some aspects of the proposed principle;
• 14 is an embodiment of a method for producing a housing with laser arrangements according to some aspects of the proposed principle.

DETAILED DESCRIPTION

The following embodiments and examples show various aspects and their combinations according to the proposed principle. The embodiments and examples are not always true to scale. Likewise, various elements may be shown enlarged or reduced in size to emphasize individual aspects. It goes without saying that the individual aspects and features of the embodiments and examples shown in the figures can be easily combined with one another without compromising the inventive principle. Some aspects have a regular structure or shape. It should be noted that in practice, slight deviations from the ideal shape may occur without, however, contradicting the inventive idea.

Furthermore, the individual figures, features, and aspects are not necessarily depicted in the correct size, nor are the proportions between the individual elements necessarily accurate. Some aspects and features are emphasized by being enlarged. However, terms such as "top," "above," "below," "below," "larger," "smaller," and the like are correctly depicted in relation to the elements in the figures. This makes it possible to infer such relationships between the elements from the illustrations.

1 shows in cross section a design of a laser arrangement as it can be used, for example, in the proposed housing.

The laser arrangement of the 1 is designed as an edge-emitting laser. For this purpose, it comprises a substrate 10 made of a semiconductor material that is suitable and configured to generate laser light of a specific wavelength. The semiconductor material of the substrate 10 can, for example, be based on a phosphorus material system, which is designed, among other things, to generate laser light in the orange or red range. Nitrite-based material systems, on the other hand, are suitable for generating light in the blue or green range of the visible spectrum.

The laser arrangement comprises n- and p-doped regions, which are not shown here for the sake of simplicity, as well as an active zone arranged between them for generating the laser light. A laser ridge 12 is etched or otherwise created into the substrate 10 above this active zone. This ridge contributes to carrier confinement and forms a longitudinal resonator for generating laser light. In this embodiment, the laser ridge 12 is p-doped, whereby the active zone adjoins the substrate 10 below. The resonator 12 is provided at one end with a highly reflective material 121, which reflects the light generated in the active zone. A semi-transparent mirror 122, i.e., a mirror with slightly lower reflectivity, is arranged at the other end. The mirror 122 thus forms the output facet of the resonator and the laser arrangement. Both mirrors can be vapor-deposited or otherwise applied directly onto the surfaces of the laser ridge 12.

The laser arrangement of the 1 further comprises a first contact region 11 on the substrate 10, which serves as an n-contact, and a second contact region 14. This is arranged on a thin passivation layer 13 on the laser ridge 12 and serves as a contact for the laser ridge to generate the light within the active zone. The passivation layer 13 comprises several openings for contacting. In addition, the second contact region 14 can also have not shown here Have pressure relief elements so that the laser burr 12 is not subjected to additional stress during subsequent assembly of the laser arrangement 1.

In this context, the laser arrangement of the 1 the p-contact region 14 is defined as a bottom side of the arrangement, a corresponding top side of the laser arrangement is defined by the first contact region 11.

In addition, the laser arrangement of the 1 also an output coupling or mirror element 20. This is designed as a recess within the substrate 10 and extends essentially perpendicular to the output facet 122 of the laser ridge 12. It thus cuts out a region from the laser ridge 12, so that this is divided into a left part, shown here, acting as a resonator, and a right-hand region 12' separate from it. The mirror element 20 comprises an oblique side surface opposite the output facet 122, which is highly reflective. Laser light L coupled out from the output facet 122 is deflected by the mirror surface 22 of the oblique side and essentially perpendicular to the laser ridge 12, as shown in the 1 shown radiated.

This means that the 1 The laser arrangement shown represents a so-called bottom-emitter laser, i.e., a laser arrangement that radiates downwards. The distance between the mirror element 20 and the right-hand side edge 10' of the substrate 10 is shown enlarged. This distance is usually kept as small as possible in order to bring the different laser arrangements as close together as possible. It is often only a few µm, e.g., in the range of 20 µm to 40 µm, but can also be significantly smaller.

2 shows a plan view of the underside of the laser arrangement according to the invention based on the proposed principle. In this embodiment, two laser ridges 12 are arranged next to one another and covered by a common metallic contact 14. The metallic contact region 14 extends over the entire laser ridge in the present exemplary embodiment, but can also be designed to be shorter depending on the implementation and design. In particular, it can be arranged laterally slightly offset from the output facet 122, so that this is spaced apart from the metallization of the contact region 14. On the rear side of the laser ridges, a highly reflective material 121 is applied as a mirror for the resonators and thus covers both laser ridges in the plan view of the 2 .

In this embodiment, the laser arrangement is thus designed to generate laser light of a specific wavelength through both laser ridges. By individually controlling the two laser ridges on the substrate, the intensity of the emitted laser light from this arrangement can be adjusted over a wide range. However, the distance between the two laser ridges is small, amounting to only a few µm, so that a point-like light source can be assumed during operation, regardless of which laser ridge is currently active. The distance between the mirror surface 22 of the mirror element 20 and the side surface 10' of the substrate 10 is as small as possible in order to achieve a compact arrangement of various laser arrangements of this type.

3 shows a design of a housing with three laser arrangements designed in this way for generating a very compact coupling-out or emission surface 50. The housing is, on the one hand, very flat and compact and, in addition, allows individual control of each individual laser arrangement for generating light of different wavelengths or also the existing multiple ridges of each laser arrangement. 3 shows the laser arrangement in a “bottom emitter” configuration similar to the 2 . 4 shows a side view of this housing design.

The individual substrates 10b, 10g, and 10r each comprise four separately and individually controllable laser ridges. For control purposes, several supply lines 351b, 351g, and 351r are arranged on the side of the substrates facing a cover 35, i.e., on the respective p-doped side, so that they can individually supply the respective laser ridges with current. The supply lines are applied as metallization surfaces.

The 3 The arrangement of the supply lines shown does not necessarily correspond to an implementation, but merely represents one possibility for the separate, individual control of the individual laser ridges. Perpendicular to the individual laser ridges, a recess is arranged in each substrate 10. This recess has a reflective side surface on a side opposite the respective output facet 122 and thus directs the laser light generated by the respective S laser ridges out of the plane towards a transparent cover 35. The individual substrates 10b, 10g and 10r are attached here with their respective p-sides to the transparent cover 35. This can be done, for example, via a glass solder or a glass-ceramic connection, provided that the carrier 35 outside the emission surface 50, which essentially corresponds to the coupling-out region, is a ceramic substrate, a semiconductor substrate or a metallic substrate. In such a case, the cover forms a transparent portion with a surrounding frame, which is connected to the substrates and has a higher thermal conductivity.

Also attached to the cover 35 are several longitudinally directed metallizations 350, which are suitable for connection to a wire connection. By means of the wire connection, a contact is created to the respective rear side of the individual substrates 10r, 10b, and 10g and to the connection pads there in order to electrically contact the respective active zones beneath the laser ridges. The individual metallized leads 350 and 351b, 351g, and 351r are routed along the cover 35 to a circumferential edge of a frame 31. There, they are connected to corresponding metallized feedthroughs or vias within the edge region. Figure 4 shows these feedthroughs in side and cross-sectional views.

The individual substrates 10r, 10g, and 10b are connected to the cover 35 via a metallic solder connection. The metallization 350, also applied to the cover, is electrically connected to the n-doped side and to the contact elements there (not shown here) via a wire connection 352. The corresponding metallizations 350 and metallized leads 351 are electrically connected to vias and feedthroughs of a frame 31. The feedthroughs extend to the underside of the frame and a base plate 32 and contact the contact surfaces 33 on the outside of the base plate 32, i.e., the side facing away from the cover. In other words, several contacts are routed through the frame in this way and attached to contact surfaces 33 on the underside of the frame. The height of this frame, i.e., of the base plate 32 and the surrounding frame 31, is selected such that the individual vias and contacts are not connected to the base plate. Nevertheless, this arrangement is relatively space-saving, since the height of the frame depends solely on the design and spacing of the respective bond wires 352.

The dimensions of the radiating surface 50 are approximately in the range of 50 µm by 250 µm. However, it essentially depends on the geometry of the individual substrates 10b, 10g, and 10r on the cover and their relative arrangement.

In the top view in the 3 This is indicated, for example, by the dashed line. The substrates 10b and 10g for blue and green laser light are arranged parallel to one another, the substrate 10r is arranged centrally with its side surface 10' adjacent to the mirror element 20 opposite the respective side surfaces 10' of the substrates 10b and 10g. By placing the individual substrates even closer together and reducing the distance between the respective mirror elements 20 and their adjacent side surfaces 10', an even smaller radiation surface 50 and thus radiation similar to a point-like light source can be achieved. The substrates 10b, 10g and 10r can also be permuted, but it is expedient to arrange substrates of approximately the same length, i.e. with a similar resonator length, parallel to one another in order to reduce the size of the housing overall.

In this exemplary embodiment, the cover 35 is designed as a completely transparent carrier. However, this is not absolutely necessary; the carrier can also be designed as a metal-glass or ceramic-glass compound, with the respective glass compound being arranged as a transparent region above the radiating surface 50. An additional ceramic, metallic, or semiconductor frame not only improves the contacting options of the respective substrates on the cover, but also improves heat dissipation during operation of the arrangement.

In the design of the 3 and 4 A hermetic seal is provided between the cover 35 and the frame 31 to prevent possible contamination in the receiving space 34. However, this is not absolutely necessary. The hermetic seal serves primarily to prevent dirt or oxidizing substances from accumulating on the emission area due to an optical tweezer effect. However, the very close arrangement or the small distance between the transparent portion of the cover 35 and the mirror elements 20 of the individual substrates 10b, 10g, and 10r largely prevents an optical tweezer effect. This has the advantage that a completely hermetic seal, as in conventional techniques, can be dispensed with.

5 shows a further embodiment in which the cover has additional functionality. Here, too, the cover 35 comprises a transparent partial area, which essentially corresponds to the radiating surface 50. In addition, however, partial areas are arranged around this radiating area, which have a plurality of contact surfaces 33. The contact areas on the upper side of the cover 35 are connected via feedthroughs through the cover to respective metallizations or leads 350 and 351 on the inside of the cover 35. The substrates 10b, 10g and 10r are in turn soldered with their p-doped sides onto the inner metallized leads 351. Here, too, pressure relief can be achieved by additional elements. (to reduce pressure on the laser burrs during assembly) and a further fastening for heat dissipation on the cover 35, which are connected to the cover by a solder joint.

N-type contact pads on the top side of the substrates are connected to the metallizations and contact pads 350 via additional bond wire connections 352. Although this embodiment required a significantly more complex production of the cover, it also resulted in a simplified structure of the respective frame comprising elements 31 and 32. This frame can be manufactured more easily and can be mounted easily and without major alignment. The requirements for the surface of the frame and the quality of the material are also reduced.

Accordingly, arrangement in the 5 The cover and frame can simply be manufactured separately. The substrates 10r, 10b, and 10g are then separately applied to the cover 35 and contacted. The housing with frame is then placed on the cover and firmly connected to it. Here, too, the receiving space 34 is designed to be as space-saving and narrow as possible and essentially depends on the curvature and geometric configuration of the bond wire connections 352. If a connection to the n-doped side of the laser is created in the substrates through feedthroughs or otherwise without a wire connection, such a receiving space 35 can be largely dispensed with, and the housing becomes correspondingly thinner.

6 shows a further embodiment in plan view, in which the individual substrates 10b, 10g and 10r are now applied to the side of a base plate within the frame. 7 is the corresponding side view. This embodiment is similar to conventional techniques, in which the laser devices are placed, fastened, and electrically contacted in a housing on a base plate of a frame. The frame is then hermetically sealed with a cover 35. In this exemplary embodiment, the upper side of the substrates is guided to the contacts with the metallizations 350, and the respective p-doped laser ridge is connected via a corresponding bond wire connection 352 to additional contact areas 33' on the inside of the base plate within the housing. The individual contact areas on the inside of the base plate 32 are then electrically connected via feedthroughs through the base plate to contact surfaces 33 on the outside. In this exemplary embodiment, the distance between the cover 35 and the individual mirror elements 20 of the substrates 10b, 10g, and 10r or the laser arrangements is significantly greater, so that an optical tweezer effect can no longer be completely avoided. Accordingly, in this embodiment it is expedient to provide a hermetic seal between the cover 35 and the frame 31.

In previous designs, the respective laser arrays are designed as so-called "bottom emitters" and, depending on the design, are attached either to the base plate of the housing or to the underside, i.e., the inside of the cover 35. This presupposes, however, that the laser arrays can be designed as emitters radiating toward the underside. If this is not the case, and some laser arrays are only available as edge-emitting lasers, the individual laser arrays can still be aligned to one another in a very space-saving manner. Even with such designs, a small radiation area 50 can be achieved, which is in the range of less than 10 µm x 10 µm.

An example design is shown in the next 8 , 9 , 11 and 12 In these, the individual substrates are essentially aligned in two mutually perpendicular planes. In other words, at least two of the substrates are tilted relative to each other, in particular tilted by 90° relative to each other. Furthermore, the two laser arrangements are designed differently. For example, one of the substrates can be configured as a "bottom emitter" as described above, while the other substrate comprises only one or more conventional edge-emitting lasers. 8 shows such an embodiment.

Here, an edge-emitting laser arrangement is combined with bottom-emitting laser diodes or such laser arrangements on a three-dimensional, partially metallized submount 100. The submount 100 comprises a surface that is metallized at least in partial areas and has a plurality of metallized structures 350 that either extend through the submount (not shown here) or are connected along the surface to contact surfaces 33. The submount 100 comprises a semiconductor material or a ceramic material and serves primarily for heat dissipation during operation of the individual laser arrangements 10g, 10b, and 10r.

In the present embodiment, two laser arrangements 10g and 10b are arranged side by side on a top side of the submount and are electrically connected there to the metallizations 350. The metallization 350 also forms a common contact. The two laser arrangements 10g and 10b are designed with laser ridges as "bottom emitters" and comprise a mirror element 20, which reflects the generated laser light perpendicular to the lower main side of the respective submount. strate. The substrates are arranged near an edge of the submount 100.

On a perpendicular side surface of the submount 100, a third substrate 10r is applied as an edge-emitting laser and is also soldered to the metallization of the submount. On the top side, a bonding wire 352 leads to a corresponding metallization, which in turn is led to one of the contact surfaces 33 on the underside of the submount 100. The substrate 10r is designed as an edge-emitting laser using conventional technology, so that the output facet coincides with the side edge of the substrate. As shown in the figure, the respective output facets and mirror elements of the individual substrates are arranged close to a common side edge of the submount 100, resulting in a very small common radiation area 50. The submount 100 can then be applied to a simple base plate using a sintering process, which in turn provides several through-holes to the outside. Using a further process, such as gold-tin or glass soldering, a glass cap is soldered over this submount, creating a sealed housing.

The advantage of such a design with a combination of conventional edge-emitting lasers and bottom-emitting laser diodes is that such a design as a bottom emitter does not have to be present for all colors or lasers used. Rather, a very small emission area 50 can also be achieved using the process shown by arranging the individual laser diodes at an angle. In this context, the overall coupling-out area depends primarily on the geometric alignment of the substrates 10b, 10g, and 10r on the submount 100. The tolerances of the submount 100 can be neglected by using a suitable process during assembly of the substrates. Furthermore, this design is particularly suitable for good thermal conduction due to the larger amount of material.

11 shows the design with the submount of the 8 in a hermetically sealed housing. The housing height is selected such that the cover 35 with a transparent area lies just above the submount 100, so that the emission area 50 nevertheless remains as small as possible. In this embodiment, bond wires 352 are routed, on the one hand, to the surface of the red laser diode 10r and, on the other hand, to the leads 350 on the top side of the submount 100. These lead, in the receiving space formed by the package with frame 31 and base plate 32, to contacts 33' on the inside of the base plate 32. The contacts 33' are connected via feedthroughs to the contact surfaces 33 on the outside of the base plate. Feedthroughs 33" through the submount are also provided, which are also connected to contacts 33'. The additional submount ensures better heat dissipation during operation of the arrangements. In addition, as shown in the 10 As will be explained, several emitting structures can be arranged along the corners on the submount so that the package is suitable for a large number of laser diodes.

9 shows a further embodiment in which various laser diodes are also aligned at an angle to one another and are fastened in different ways both to the cover 35 and to a submount. The embodiment shows a housing with laser arrangements 10g, 10b and 10r. As in the previous embodiments, the housing comprises a circumferential frame 31 and a base plate 32 in which various feedthroughs are arranged. A submount 100 is provided in one part of the housing, to which a first substrate 10r is soldered. The upper side of the substrate faces the submount 100 and is guided via a contact surface with a feedthrough through the submount to a contact surface 33. The underside with the laser ridge thus points away from the submount 100. In the illustrated embodiment, the submount is fastened both to the base plate and to the frame. The substrate 10r comprises a normal edge-emitting laser with a multiple laser ridge or a single laser ridge structure.

Two additional bottom-emitting lasers 10g and 10b are now arranged on the cover, as already shown, for example, in the previous exemplary embodiments. By appropriately aligning these substrates with the substrate 10r on the submount 100, an overall very small radiation area 50 can be achieved while simultaneously avoiding the optical tweezer effect. Depending on the design of the metallization elements on the cover 35, it is also possible to apply this cover offset during assembly in order to achieve the closest possible alignment of the two laser arrangements 10g and 10b to the edge-emitting side of the laser arrangement 10r. For example, it is possible to shift the cover slightly to the right or left, provided the feedthroughs in the frame 31 remain in contact with the metallizations 350 and leads 351 on the underside of the cover. This minimizes the radiation area 50 for the housing or sets it to the desired value.

12 shows a slight modification of the design of the 9 . On the submount 100, supply lines 351R are provided, which connect the laser diode 10r via a through-hole to the contact area 33 on the outside of the base plate 32. Furthermore, supply lines 351g for the green diode 10g (and the blue one, not shown) are arranged on the inside of the cover, which in turn are connected to feedthroughs in the frame. The feedthroughs in the frame 31 connect these supply lines to contact areas 33. Various configurations are therefore conceivable, allowing edge-emitting lasers to be combined with bottom-emitting lasers in a common package, while still minimizing the common radiation area.

10 shows a further embodiment of the invention, in which the submount 100 is designed as a ceramic cube for improved heat dissipation. On its upper side 100o, the cube is characterized by four corners 110. At each of these four corners, laser arrangements (shown here only at two corners) are applied in the form of substrates on the respective surface, with two substrates each, in this case 10r and 10b, being designed as conventional edge-emitting lasers. In the illustration of the 10 Two corners are provided with such structures, the other two corners are not shown for reasons of clarity.

The two substrates 10r and 10b are attached to the surface 100o on two perpendicular surfaces near their respective common corners 110. Feedthroughs through the substrate or bonding wires (not shown here) allow contacting of the respective laser arrays 10r and 10b through the submount. For this purpose, the submount can be hollow, for example, on its underside to guide possible metallization contacts inside the submount to the desired location on the feedthroughs. Two additional laser arrays 10g are mounted on the top side 100o as bottom emitter lasers.

With a suitable design of this submount, this arrangement enables the formation of a total of four individual, very small radiation surfaces in the range of 50 µm to 250 µm, which in turn are characterized by individually controllable laser arrangements. Depending on the size of the substrates and the geometric dimensions, in particular the bottom-emitting laser on the top side 100o, four radiation surfaces can be created in this way at a defined distance from one another. Furthermore, such a submount can be manufactured very easily by first populating the various sides separately. The individual surfaces can then be joined together perpendicular to one another. The leads to the individual substrates are applied to the respective underside of a surface, which then forms the inside of the submount.

In addition to the cube-shaped submount 100 shown here, cuboid structures or other shapes can also be designed in a similar way. For example, it is possible to use a polyhedron with six sides in plan view in the form of a hexahedron as the submount, with each corner of this hexahedron in turn comprising its own beam area with three laser arrays.

The 13A and 13B 11 and 12 show the cross-sectional view and the front view of a package according to a further embodiment. The package is designed as a so-called side emitter; it comprises a stone wall with a transparent radiating surface 31'. The laser diode 10r is mounted on a submount and connected to it via leads 351 and feedthroughs 33" in the submount with contact surfaces 33' on the inside of the base plate 32. The diode 10r is designed as a conventional edge-emitting laser, whereby several laser ridges can be present on the substrate and can be individually controlled. This allows the output power to be adjusted over a larger range.

In addition, the housing includes two further bottom-emitting lasers 10g, 10b, which are arranged directly on the side wall above the transparent area. Their arrangement and fastening are carried out as in the previous examples on the inside of the wall above the transparent area. As shown in the front view of the 13B As shown, several supply lines are vapor-deposited or otherwise attached to the side wall 31', which contact the contacts on the structures or the laser ridges. The supply lines are then routed along the inside to feedthroughs in the base plate, where they are connected to contacts 33. The emission areas with the reflective sides 20, or the emitting edge, are recessed from the supply lines. The contact surfaces 33' on the inside are designed to be larger, so that the submount 100 can also be aligned during placement, so that the emitting edge of the laser diode is adapted as closely as possible to the output area, thus making the emission area 50 small.

14 shows possible process steps for the production and manufacture of a housing with such laser arrangements and in particular bottom-emitting lasers. In a first step S1, various laser arrangements The device is designed as a "bottom emitter." These are separated from each other and have elements on their p-doped side that allow the substrates to be placed on a corresponding substrate in a pressure-relieved manner.

In step S2, a cover is provided. In this embodiment, the cover comprises a ceramic-glass connection, i.e., a glass portion acting as a window, which is surrounded by a ceramic substrate. The ceramic substrate serves to improve heat dissipation and is configured in a preceding step such that corresponding metallic connections are applied to the ceramic substrate. This can be done, for example, by vapor deposition or another appropriate deposition method. The metallic leads and structures are configured to correspond to contact surfaces on the respective p-doped side of the individual substrates of the laser arrangements.

In the next step S3, a thin layer is applied to the metallic connections. Alternatively, the laser can be applied straight onto this solder layer. Subsequently, in step S4, the substrates are applied with the laser burrs facing the solder material and aligned so that the mirror element of the respective substrate is opposite the transparent section of the cover. After alignment, they are attached to the cover, for example by soldering or other means. Pressure relief is achieved by elements next to the laser burr that protrude slightly over the burr so that it does not feel too much force when placed and pressed down. This improves the service life and prevents possible damage when assembling the housing with the laser arrangements.

Subsequently, in step S5, the required bond wire connections are created by connecting the exposed contacts on the remaining surface of the substrate to corresponding metallizations on the cover. The metallizations are routed outward along the inside of the ceramic layer.

The metallizations can now lead to feedthroughs that lead to contact surfaces on the top side of the ceramic layer. The contact surfaces are arranged, for example, around the transparent portion of the cover. Alternatively, these feedthroughs are arranged in a frame provided in step S6.

In some embodiments, this in turn comprises several correspondingly aligned feedthroughs. In step S6, the cover is then placed on the frame with the base plate, and the corresponding metallization of the ceramic layer is soldered to the feedthroughs. A hermetic connection is not necessarily required, since the distance between the mirror elements of the laser array and the transparent portion of the cover is so small that an optical tweezer effect does not occur. For example, the distance can be as little as a few micrometers up to, for example, 100 µm or 200 µm, effectively preventing an optical tweezer effect.

LIST OF REFERENCE SYMBOLS

10

Substrat

10b, 10g

Substrat

10r

Substrat

10'

side surface

11

Contact area

12, 12'

Laser burr

13

passivation layer

14

Contact area

20

Mirror element

22

mirror surface

31

Frame

32

base plate

33

Contact surfaces

35

Lid

50

Radiating surface

100

Submount

100o

surface

110

Corner

121

highly reflective material

122

Output facet

350

Metallization

351

supply line

351b

supply line

351r

supply line

351g

supply line

352

Bonding wire

L

Laser light

Claims (18)

Housing with laser arrangement, comprising: - a cover which has a transmissive surface for laser radiation parent subregion; - a first substrate with at least one first edge-emitting laser ridge designed as a resonator and having an output facet for emitting laser radiation of a first wavelength; - a second substrate with at least one second edge-emitting laser ridge designed as a resonator and having an output facet for emitting laser radiation of a second wavelength; - optionally a third substrate with at least one third edge-emitting laser ridge designed as a resonator and having an output facet for emitting laser radiation of a third wavelength; - wherein at least one of the first, second and optionally third substrates is designed with at least one mirror element for deflecting the laser radiation emitted by the corresponding edge-emitting laser ridge in the direction of the transparent subregion; and wherein each of the substrates has a side surface that is adjacent to or coincides with the respective output facet, and the side surfaces of two of the substrates are at least partially adjacent to one another and opposite one another. Housing according to Claim 1 , in which - at least a second of the first, second and optionally third substrates has a mirror element designed to deflect the laser radiation emitted by the corresponding edge-emitting laser ridge in the direction of the transparent partial region; or - the first, second and optionally third substrates each have a mirror element designed to deflect the laser radiation emitted by the corresponding edge-emitting laser ridge in the direction of the transparent partial region. Housing according to one of the preceding claims, in which the mirror element has a recess in the respective substrate, wherein one side surface of the recess has the respective output facet and an opposite reflecting side surface is arranged obliquely with respect to the respective output facet. Housing according to one of the preceding claims, wherein the mirror element is laterally spaced from the side surface for deflecting the laser radiation emitted by the corresponding edge-emitting laser ridge. Housing according to one of the preceding claims, in which the at least one of the first, second and optionally third substrates is connected to the cover, in particular by a metallization, such that an optical tweezer effect is suppressed by a distance between the mirror element and the transparent partial region, wherein optionally the metallization is designed as a contact for electrical connection to the at least one laser burr. Housing according to one of the preceding claims, in which at least one of the first, second and optionally third substrates comprises a plurality of edge-emitting laser ridges designed as a resonator, each with an output facet for emitting laser radiation, which can optionally be controlled separately. Housing according to one of the preceding claims, in which the cover comprises a metallization which electrically contacts a side of the at least one of the first, second and optionally third substrates facing away from the cover, in particular via a wire connection. Housing according to one of the preceding claims, further comprising a frame which is connected to the cover to form a receiving space, in particular a hermetically sealed space, in which the first, second and optionally third substrate are arranged. Housing according to one of the preceding claims, further comprising a number of contact surfaces on an outer side of the cover and/or the frame and with a plurality of conductive feedthroughs through the cover and/or through the frame. Housing according to one of the preceding claims, in which the cover outside the transparent partial region comprises a material, in particular one made of a metal and silicon, which has a higher thermal conductivity than a material of the transparent partial region. Housing according to one of the preceding claims, in which two of the substrates are arranged next to one another with output facets pointing in the same direction and/or a third of the substrates is arranged opposite the two substrates with the output facet Housing according to one of the preceding claims, in which one of the substrates is tilted, in particular arranged at 90° to the other two substrates, wherein - at least one of the substrates is formed with at least one edge-emitting laser ridge designed as a resonator; and - at least one of the substrates is formed with at least one first edge-emitting laser ridge designed as a resonator, at the output facet of which a mirror element is arranged within the substrate for deflecting the lasers emitted by the corresponding edge-emitting laser ridge. radiation is arranged in the direction of the transparent part. Housing according to one of the Claims 11 until 12 , further comprising at least one submount on which at least one of the substrates with the at least one edge-emitting laser ridge designed as a resonator is arranged. A method for processing an optoelectronic component, comprising the steps of: - providing a cover with a transparent partial region; - arranging a first substrate with at least one first edge-emitting laser ridge configured as a resonator and having an output facet for emitting laser radiation, wherein the edge-emitting laser ridge faces the cover, and the first substrate comprises a mirror element for deflecting the laser radiation emitted by the corresponding edge-emitting laser ridge toward the transparent partial region; - providing at least one further substrate with an edge-emitting laser arrangement; - arranging the at least one further substrate such that a side edge of the at least one further substrate adjacent to an output facet of the laser arrangement is adjacent to a side edge of the first substrate adjacent to the mirror element; - attaching the cover to a frame with base plates, forming a receiving space, so that the substrates are arranged in the receiving space. Procedure according to Claim 14 , wherein the at least one further substrate comprises a mirror element for deflecting the laser radiation emitted by the corresponding edge-emitting laser ridge in the direction of the transparent partial region and is arranged on the cover such that the side edge of the further substrate adjacent to the mirror element is opposite the side edge of the first substrate. Procedure according to Claim 14 , in which the further substrate is tilted relative to the first substrate, in particular by 90°. Method according to one of the Claims 14 , in which the provision of a cover with a transparent partial region comprises: - providing a cover with a transparent partial region which is surrounded by a non-transparent partial region with a higher thermal conductivity than the transparent partial region, in particular made of a ceramic, a metal, a semiconductor or a combination thereof. Providing a cover having at least one metallization serving as a contact, which is in electrical connection with the edge-emitting laser ridge, wherein - the metallization is electrically connected to a feedthrough in the frame, the feedthrough leading to an underside of the base plate; or - the cover has one or more feedthroughs connected to the metallization and leading to contact surfaces on an upper side of the cover.

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