Semiconductor laser

Abstract

To provide a semiconductor laser that can operate efficiently.SOLUTION: A semiconductor laser 20 includes: a carrier 21; an edge-emitting laser diode 22 that is arranged on the carrier 21 and has an active region for generation of laser radiation; a facet 23 having a radiation exit region 24; an optical element 25 covering the facet 23; a connection member 26 arranged between the optical element 25 and the facet 23; and a molded body 27 covering at least partially the laser diode 22 and the optical element 25. The optical element 25 is at least partially transparent to the laser radiation that is emitted by the laser diode 22 in operation. The optical element 25 is designed to change a main propagation direction of the laser radiation entering the optical element 25 in operation.SELECTED DRAWING: Figure 1

Description

Background Art

[0001] A semiconductor laser is specified.

Summary of the Invention

Problems to be Solved by the Invention

[0002] An object of the present disclosure is to specify a semiconductor laser that can be operated efficiently.

Means for Solving the Problems

[0003] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser includes a carrier. The carrier can be a so-called submount. The carrier can be a three-dimensional body, for example, having a cylindrical, disk, or cubic shape. The carrier can have a main extension plane. For example, the main extension plane of the carrier is parallel to a surface such as the upper surface of the carrier. The carrier can include a semiconductor material.

[0004] It is possible for the carrier to include a driver that can control the semiconductor laser. Alternatively, the carrier can represent an electronically passive component and function only at the mounting level.

[0005] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser comprises an edge-emitting laser diode disposed on the carrier and having an active region for generating laser emission and a facet with a radiation exit region. The edge-emitting laser diode is designed to emit laser emission in a direction at least partially parallel to the main extension plane of the carrier during operation. The active region has a main extension plane parallel to the main extension plane of the carrier. Therefore, the laser diode is not a surface emitter.

[0006] The laser diode can include different semiconductor materials based on, for example, a III-V semiconductor material system. The laser diode can be disposed on the upper surface of the carrier. The laser diode can be connected to the carrier via an electrical contact, whereby the laser diode can be controlled via the carrier. For example, the laser diode has an electrical contact on the side facing the upper surface of the carrier, and the contact is electrically connected to the carrier. Alternatively, it is also possible that the laser diode is electrically connected to the carrier via a bonding wire. The laser diode may be mechanically attached to the upper surface carrier.

[0007] The facet is oriented laterally, preferably orthogonally to the main extension plane of the active region. Further, the facet is oriented laterally, preferably orthogonally to the main propagation direction of the laser radiation emitted during operation. In the radiation exit region, the laser radiation generated during operation exits the laser diode. The radiation exit region is, in particular, a partial region of the facet and is thus limited to the facet.

[0008] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser consists of an optical element covering the facet. The optical element can be designed to shape the emitted laser radiation. The optical element can completely cover the facet. For this purpose, the optical element can be attached to the facet. Also, the optical element can completely cover the radiation exit region.

[0009] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser includes a connection member disposed between the optical element and the facet. The connection member can at least partially cover the facet. For example, the facet is open from the connection member in the radiation exit region. It is also possible for the connection member to completely cover the facet. The optical element is mechanically attached to the laser diode via the connection member.

[0010] In particular, the connection member is arranged between the optical element and the facet in such a way that the radiation exit region is enclosed as much as possible. This means, for example, that the connection member is arranged around the radiation exit region. Alternatively, the connection member can completely cover the facet and enclose the facet. The fact that the radiation exit region is enclosed can mean that the radiation exit region is hermetically sealed against the environment of the semiconductor laser. By enclosing the radiation exit region, the radiation exit region is protected from environmental influences, for example mechanical or chemical influences from the environment of the semiconductor laser. For example, the water vapor transmission rate through the connection member is at most 1×10 -3 g / m 2 / day, preferably at most 3×10 -4 g / m 2 / day.

[0011] Also, the connection member may contain an inorganic material such as glass or metal. Furthermore, the connection member may contain a plastic such as silicone, silicone derivative, silazane, siloxane, polysiloxane, polysilazane, or a silicone hybrid material. Alternatively, the connection member may contain an epoxy or polymer of a carbon-containing structural unit.

[0012] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser comprises a molded body that at least partially covers the laser diode and the optical element. The molded body may be a sealing body. The molded body is designed to protect the laser diode from environmental influences. The molded body can be formed by an injection molding method, a so-called Dam&Fill process, or a spray (injection) method. For example, the molded body contains an epoxy resin, a thermoplastic resin, silicone or a silicone derivative.

[0013] According to at least one embodiment of the semiconductor laser of the present invention, the optical element is at least partially transmissive to the laser radiation emitted during operation by the laser diode. This means that the laser radiation generated during operation can at least partially pass through the optical element. On the radiation inlet side of the optical element facing the radiation outlet region, at least a part of the laser radiation emitted by the laser diode can be incident on the optical element. On the radiation outlet side of the optical element, at least a part of the laser radiation can exit the optical element. The optical element can include sapphire, diamond, SiC, or an organosilicon compound. In particular, the optical element exhibits low absorption of the laser radiation emitted during operation by the laser diode. Furthermore, the optical element may have a high thermal conductivity.

[0014] According to at least one embodiment of the semiconductor laser of the present invention, the optical element is designed to change the main propagation direction of the laser radiation incident on the optical element during operation. The laser radiation emitted by the laser diode can have, for example, a main propagation direction parallel to the main extension plane of the carriers. The main propagation direction may be the beam direction of the laser radiation. The laser radiation emitted from the semiconductor laser has a main propagation direction different from the main propagation direction of the laser radiation emitted by the laser diode. By passing through the optical element, the main propagation direction of the laser radiation changes. For example, the main propagation direction of the laser radiation emitted from the laser diode is transverse or orthogonal to the main extension plane of the carriers.

[0015] For this purpose, the optical element can have the shape of a fragment of a sphere or an ellipsoid. For example, the optical element has the shape of a quarter sphere. That is, the shape of the optical element corresponds to one quarter of a sphere.

[0016] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser includes an edge-emitting laser diode including a carrier and a facet disposed on the carrier and having an active region and a radiation exit region for generating laser emission, an optical element covering the facet, a connecting member disposed between the optical element and the facet, and a molded body at least partially covering the laser diode and the optical element. The optical element is at least partially transmissive to the laser emission emitted during operation by the laser diode, and the optical element is designed to change the main propagation direction of the laser emission incident on the optical element during operation.

[0017] The semiconductor laser described herein is based on the idea that it can operate under normal atmosphere without the need for additional hermetic sealing. This means that the encapsulation and protection of the facet, particularly the radiation exit region, are achieved by the connecting member together with the optical element. Further, the laser diode is encapsulated by the molded body. This means that the semiconductor laser does not require a hermetically sealed housing. The optical element disposed on the facet and the molded body already protect the laser diode and the facet from the influence of the environment. Therefore, there is no need to dispose the laser diode in a larger housing within the cavity and encapsulate the housing. Therefore, less installation space is required for the semiconductor laser.

[0018] By sealing the facet, the facet is protected against the deposition of particles from the environment of the laser diode. The deposition or accumulation of particles on the facet can cause an interaction with the emitted laser radiation, especially in the radiation exit region, and can cause heating in the region of the facet. This can lead to the destruction of the laser diode. The deposits on the facet can be decomposed and charred, especially by short-wave radiation. Such changes in the region of the facet can reduce the decoupling efficiency of the semiconductor laser and can damage the facet coating, for example, by light absorption in the deposits, resulting in overheating. Therefore, it has been proven that it is particularly advantageous to seal the facet with a connecting member. Furthermore, the semiconductor laser enables more cost-effective manufacturing and can be installed with a reduced required installation space.

[0019] By using an optical element, the beam divergence of the laser radiation emitted from the laser diode can be reduced. Otherwise, the electric field strength of the divergent beam can suck in contaminants that may be near the facet, like an optical tweezer, and deposit them on the facet. Thus, the reduction of beam divergence immediately leads to a reduction in deposits.

[0020] Furthermore, by using an optical element, the interface with the atmosphere can be increased. By increasing the interface, the possible deposition amount per unit area is reduced. Furthermore, the energy density at this interface is reduced compared to the energy density at the direct facet.

[0021] The optical element also offers the possibility of shaping and redirecting the laser radiation emitted from the laser diode. Thus, an edge-emitting laser diode can be used for a surface-emitting semiconductor laser.

[0022] Since the optical element can include a material with a high thermal conductivity, heat can be dissipated through the optical element. Thereby, overheating of the facet can be prevented.

[0023] Since the semiconductor laser already constitutes an optical element, the downstream optical system can be made smaller and simpler. Overall, the integration of optics, logic, and sensor technologies near the semiconductor laser is simplified by reducing the installation space.

[0024] Advantageously, the semiconductor laser can be manufactured as a composite body and separated into individual semiconductor lasers in the latter half of the manufacturing process.

[0025] According to at least one embodiment of the semiconductor laser of the present invention, the molded body completely covers the laser diode on at least one side. The molded body can completely cover the laser diode on the side opposite to the carrier. Also, it is possible for the molded body to completely cover the laser diode on the side facing laterally or orthogonally to the main extension plane of the carrier. In particular, the molded body can completely cover the laser diode on at least one side such that the molded body encapsulates the laser diode. The molded body can serve to protect the laser diode from the influence of the environment from the environment of the semiconductor laser. Due to other elements surrounding the laser diode such as the molded body and the carrier, the laser diode does not come into direct contact with the environment of the semiconductor laser. The molded body can at least partially come into direct contact with the laser diode. Thus, the molded body can be directly molded onto the laser diode. Also, by using the molded body, a surrounding housing having a cavity for accommodating the laser diode becomes unnecessary in order to protect the laser diode from the influence of the environment from the environment of the semiconductor laser.

[0026] According to at least one embodiment of the semiconductor laser of the present invention, the main emission direction of the laser diode is lateral or orthogonal to the main emission direction of the semiconductor laser. The main emission direction of the laser diode corresponds to the main propagation direction of the laser emission emitted by the laser diode during operation. Also, the main emission direction of the semiconductor laser corresponds to the main propagation direction of the laser emission emitted by the semiconductor laser during operation. This means that by passing the main propagation direction of the laser emission emitted by the semiconductor laser diode during operation through an optical element in a lateral or orthogonal direction with respect to the main propagation direction of the semiconductor laser, the main propagation direction of the laser emission emitted by the semiconductor laser during operation is changed. For example, the main emission direction of the semiconductor laser extends in a direction opposite to the carrier. Thus, the edge-emitting laser diode can advantageously be used for surface-emitting semiconductor lasers.

[0027] Furthermore, it is possible that the main emission direction of the semiconductor laser is parallel to a lateral direction parallel to the main extension plane of the carrier and not parallel to the main emission direction of the laser diode. Thus, the emission of the laser can be coupled outside the lateral direction of the semiconductor laser.

[0028] In order to change the main propagation direction of the laser emission, the optical element may have a diffractive optical structure. For example, the diffractive optical element is disposed on the emission inlet side and / or the emission outlet side of the optical element. Also, the diffractive optical element may be designed according to the shape of the laser emission.

[0029] According to at least one embodiment of the semiconductor laser of the present invention, the carrier is at least partially surrounded laterally by a shaped body, the lateral direction being parallel to the main extension plane of the carrier. This can mean that the side surfaces of the carrier in a direction lateral or orthogonal to the main extension plane of the carrier are at least partially covered by the shaped body. The shaped body may be in direct contact with the carrier in part. Also, the carrier may be completely surrounded by the shaped body in the lateral direction. In this way, the carrier and the laser diode can be encapsulated by the shaped body and protected from environmental influences from the environment of the semiconductor laser.

[0030] According to at least one embodiment of the semiconductor laser of the present invention, the shaped body is formed by a casting and / or injection molding process. These processes include all manufacturing processes in which a molding compound is introduced into a predetermined mold and in particular cured thereafter. In particular, the term casting process includes casting, injection molding, transfer molding, and compression molding. Thus, the shaped body can be molded onto the laser diode. The shaped body can have a molding compound. The shaped body formed by the casting and / or injection molding process can hermetically seal the laser diode against environmental influences.

[0031] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser has a radiation exit surface that is open from the shaped body. The radiation exit surface can be arranged on the side opposite to the carrier of the semiconductor laser. The radiation exit surface may have a main extension plane parallel to the main extension plane of the carrier. Also, the radiation exit surface may be curved or may not be planar. The radiation exit surface of the semiconductor laser may be the radiation exit surface of an optical element. Alternatively, the radiation exit surface of the semiconductor laser may be the radiation exit surface of a component of the semiconductor laser downstream of the optical element. Thus, the shaped body does not need to be transparent to the laser radiation emitted from the semiconductor laser.

[0032] According to at least one embodiment of the semiconductor laser of the present invention, the optical element completely covers the facet. This means that the side surface of the optical element facing the facet is at least the same size as the surface of the facet. The optical element completely covers the facet in the lateral direction. The optical element and the facet are connected to each other via a connecting member. Thereby, the optical element encloses the facet against the influence of the environment from the environment of the semiconductor laser.

[0033] According to at least one embodiment of the semiconductor laser of the present invention, an antireflection layer is applied on the optical element on the side facing the radiation exit region. The optical element may have a radiation entrance side facing the radiation exit region. The radiation entrance side of the optical element can have a reflectivity of 0.5% or more or 0.1% or more with respect to the laser radiation emitted by the laser diode. Thereby, the feedback of the reflected laser radiation to the laser diode can be prevented or reduced. Furthermore, the efficiency of the semiconductor laser can be improved.

[0034] According to at least one embodiment of the semiconductor laser of the present invention, the optical element has a radiation exit side on which an antireflection layer is further applied. The laser radiation incident on the optical element can be deflected within the optical element so that the laser radiation leaves the optical element on the radiation exit side. The radiation exit side of the optical element can have a reflectivity of at most 0.5% or at most 0.1% with respect to the laser radiation emitted by the laser diode. Therefore, the loss of the semiconductor laser can be minimized, and the efficiency of the semiconductor laser can be improved.

[0035] According to at least one embodiment of the semiconductor laser of the present invention, a photocatalytic layer is applied to the radiation exit side of the optical element in order to assist the decomposition reaction on the radiation exit side. The photocatalytic layer is configured to remove and / or decompose deposits on the radiation exit side by laser irradiation. In this way, the photocatalytic layer affects the reaction equilibrium between the removal of deposits and cleaning by decomposition. The photocatalytic layer is particularly formed of a metal oxide such as titanium dioxide or zirconium oxide. Alternatively, the photocatalytic layer contains platinum, palladium or rhodium. When the photocatalytic layer contains a metal, preferably, it has a thickness of 10 nm or less, or 5 nm or less, or 3 nm or less so that laser radiation can pass through the photocatalytic layer without significant loss. By applying the photocatalytic layer to the radiation exit side of the optical element in this way, the accumulation of undesirable materials can be reduced or prevented.

[0036] According to at least one embodiment of the semiconductor laser of the present invention, the optical element is designed to shape the laser radiation incident on the optical element during operation. This may mean that the optical element is designed to change the main propagation direction of the laser radiation. Also, the optical element may be designed to change other parameters of the laser radiation, such as the beam divergence. In order to shape the incident laser radiation, the optical element can have at least one diffractive optical element. In particular, the optical element can have at least one metal mirror layer or dielectric mirror layer, or a mirror layer constructed from a combination of a metal mirror and a dielectric mirror. One or more mirror layers may be disposed on the surface of the optical element. Further, the optical element may have one or more masks for shaping the laser radiation. By using an optical element designed to shape the laser radiation, the downstream optical system can be made smaller and simpler.

[0037] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser consists of two additional edge-emitting laser diodes each disposed on a carrier. The laser diode and the two additional laser diodes can be arranged side by side in the lateral direction. Each of the additional laser diodes is disposed on a carrier. Each of the additional laser diodes can have the same structure as the laser diode. Each optical element can cover a facet of one additional laser diode. The laser diode and the two additional laser diodes can be designed to generate laser emissions in different wavelength ranges during operation. This can mean that the laser diode is designed to generate laser emissions in a first wavelength range. One of the additional laser diodes can be designed to generate laser emissions in a second wavelength range, and the other of the additional laser diodes can be designed to generate laser emissions in a third wavelength range.

[0038] For example, the first wavelength range can be in the red range of the electromagnetic spectrum, for example, in the range between 600 nm and 780 nm. The second wavelength range can be in the green range of the electromagnetic spectrum, for example, in the range between 490 nm and 570 nm. The third wavelength range can be in the blue range of the electromagnetic spectrum, for example, in the range between 430 nm and 490 nm.

[0039] By using the laser diode and the two additional laser diodes, mixed light can be generated. Also, since laser emissions are possible in three different colors, for example, red, green, and blue, the semiconductor laser requires only a small installation space.

[0040] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser includes a beam combiner. The beam combiner is disposed downstream of three optical elements including a laser diode and two additional laser diodes. The beam combiner is designed to mix the laser emissions emitted by the laser diode and the two additional laser diodes to generate mixed light. For example, the beam combiner has a radiation inlet side where the laser emission exiting the optical element during operation enters the beam combiner. The beam combiner may also have a radiation outlet side where the mixed light exits the beam combiner. For example, the beam combiner is connected to the optical element by a connecting member, such as silicone. The radiation exit surface of the beam combiner can form the radiation exit surface of the semiconductor laser. Advantageously, in this way, the semiconductor laser can emit mixed light, such as white mixed light.

[0041] According to at least one embodiment of the semiconductor laser of the present invention, a conversion element designed to convert the wavelength of the radiation emitted by the laser diode during operation follows the optical element. In particular, the conversion element can be designed to convert at least a part of the wavelength of the radiation emitted by the laser diode during operation. By converting the wavelength of the radiation emitted from the laser diode during operation, for example, white mixed light with a high color rendering index can be generated.

[0042] Hereinafter, the semiconductor laser described herein will be described in more detail in conjunction with exemplary embodiments and corresponding figures.

Brief Description of the Drawings

[0043]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 5C

Figure 6

[0044] In the figures, the same, similar or equivalent elements are denoted by the same reference numerals. The ratios of the figures and the elements in the figures are not considered to be true scales with respect to each other. Rather, the sizes of the individual elements may be enlarged in order to enhance the ease of representation and / or the ease of understanding. DETAILED DESCRIPTION OF THE INVENTION

[0045] FIG. 1 shows a semiconductor laser 20 according to an exemplary embodiment. The semiconductor laser 20 consists of a carrier 21 having an extending main surface. An edge-emitting laser diode 22 is disposed on the carrier 21. The laser diode 22 has an active region for generating laser radiation and a facet 23 having an emission exit region 24. The laser radiation generated by the laser diode 22 during operation has a main propagation direction parallel to the main extension surface of the carrier 21. The semiconductor laser 20 further constitutes an optical element 25. The optical element 25 completely covers the facet 23 and the emission exit region 24. The optical element 25 is disposed adjacent to the laser diode 22 in the transverse direction x, and the transverse direction x is parallel to the main extension surface of the carrier 21. The optical element 25 has the shape of a quarter sphere. One of the flat outer surfaces of the quarter sphere faces the facet 23. Another surface of the flat outer surface of the quarter sphere faces away from the carrier 21.

[0046] A connecting member 26 is disposed between the optical element 25 and the facet 23. The optical element 25 is mechanically connected to the facet 23 via the connecting member 26. The optical element 25 is partially transmissive to the laser radiation emitted by the laser diode 22 during operation. The optical element 25 has a radiation inlet side 35 assigned to the facet 23. Further, the optical element 25 has a radiation outlet side 36 facing away from the carrier 21. Thus, the optical element 25 is configured to change the main propagation direction of the laser radiation incident on the optical element 25 during operation. This means that the main propagation direction of the laser diode 22 is orthogonal to the main radiation direction of the semiconductor laser 20. Also, the main propagation direction of the laser radiation emitted at the radiation outlet side 36 is orthogonal to the main radiation direction of the laser diode 22.

[0047] Also, the semiconductor laser 20 has a molded body 27 that at least partially covers the laser diode 22 and the optical element 25. The molded body 27 surrounds the laser diode 22, the carrier 21, and the optical element 25 in the lateral direction x. Thereby, the molded body 27 completely covers the laser diode 22 at the side surface 39. The side surface 39 of the laser diode 22 extends in a lateral or orthogonal direction with respect to the main extension surface of the carrier 21. The upper surface 37 of the laser diode 22 on the side opposite to the carrier 21 is open from the molded body 27. The radiation outlet side 36 of the optical element 25 on the side opposite to the carrier 21 is also open from the molded body 27. The radiation outlet side 36 has a planar shape, that is, a non-curved shape. The molded body 27 is formed by a casting and / or injection molding process.

[0048] The carrier 21 and the molded body 27 are disposed on a substrate 32. Here, the molded body 27 is in direct contact with the substrate 32. The substrate 32 contains a semiconductor material such as aluminum nitride. The substrate 32 is disposed on a connection carrier 31. An electrical contact 38 is disposed between the substrate 32 and the connection carrier 31. The laser diode 22 can be controlled via the electrical contact 38. The connection carrier 31 may be a printed circuit board.

[0049] Figure 2 is a top view of the semiconductor laser 20 according to another exemplary embodiment. The molded body 27 is not shown in this figure. The electrical contact 38 is disposed on the substrate 32. The electrical contact 38 is electrically connected to the laser diode 22 and the carrier 21 via the bonding wire 33. An optional ESD (electrostatic discharge) element 34 is also disposed on the carrier 21.

[0050] The optical element 25 is designed to shape the laser radiation incident on the optical element 25 during operation. For this purpose, the optical element 25 can have a diffraction element. Further, a mirror layer 40 is applied to the curved outer surface of the optical element 25. The mirror layer 40 may be a metal or a dielectric, or a combination of both.

[0051] Also, an antireflection layer may be applied to the radiation inlet side 35 of the optical element 25. Further, an antireflection layer may be applied to the radiation outlet side 36 of the optical element 25. Also, a photocatalytic layer may be applied to the radiation outlet side 36 of the optical element 25 to assist in the decomposition reaction at the radiation outlet side 36.

[0052] Figure 3 is a schematic cross-sectional view through the semiconductor laser 20 according to another exemplary embodiment. In contrast to the exemplary embodiment of FIG. 1, the molded body 27 covers the laser diode 22 at the upper surface 37 opposite to the carrier 21. Thus, the laser diode 22 is completely encapsulated and protected from environmental influences from the environment of the semiconductor laser 20. No additional housing or cavity in which the laser diode 22 is disposed is required. A through connection portion 41 is disposed in the substrate 32. The through connection portion 41 is filled with a conductive material. The through connection portion 41 extends from the side of the substrate 32 opposite to the carrier 21 towards the carrier 21. An electrical contact 38 is disposed on the side of the substrate 32 opposite to the carrier 21, through which the carrier 21 is electrically connected to the connection carrier 31. The connection carrier 31 is not shown.

[0053] Furthermore, behind the optical element 25, a conversion element 30 for converting the wavelength of the radiation emitted during the operation of the laser diode 22 is provided. The conversion element 30 has a radiation inlet side 35 facing the radiation outlet side 36 of the optical element 25. Also, the conversion element 30 has a radiation outlet side 36 on the upper surface 37 opposite to the substrate 32 of the semiconductor laser 20. In this way, the main propagation direction of the laser radiation emitted from the optical element 25 does not change significantly by passing through the conversion element 30. Also, the conversion element 30 can have a cylindrical shape. Furthermore, the conversion element 30 can have a matrix material in which conversion particles are incorporated. In the lateral direction x, the conversion element 30 is completely surrounded by the molded body 27.

[0054] FIG. 4 is a schematic cross-sectional view through the semiconductor laser 20 according to another exemplary embodiment. Only the laser diode 22, the carrier 21, and the optical element 25 are shown. Other components of the semiconductor laser 20 are not shown. The optical element 25 shows the beam path of the laser radiation emitted during operation by the laser diode 22. It is shown that the main propagation direction of the laser radiation exiting the facet 23 of the laser diode 22 is parallel to the main extension plane of the carrier 21. It is shown that the laser radiation is shaped and deflected by the optical element 25 such that the main propagation direction of the laser radiation emitted from the optical element 25 is orthogonal to the main extension plane of the carrier 21.

[0055] FIG. 5A is a top view of a semiconductor laser 20 according to another exemplary embodiment. The semiconductor laser 20 includes a laser diode 22 and two additional edge-emitting laser diodes 28. Each of the additional laser diodes 28 is disposed on a carrier 21. Further, one optical element 25 covers each facet 23 of the additional laser diodes 28. The laser diode 22 and the additional laser diodes 28 are designed to emit laser radiation of different colors during operation. For example, the laser diode 22 can be designed to emit red laser radiation during operation. One of the additional laser diodes 28 can be designed to emit blue laser radiation during operation. The other of the additional laser diodes 28 can be designed to emit green laser radiation during operation.

[0056] The three optical elements 25 are followed by a beam combiner 29. The beam combiner 29 is for mixing the laser radiation emitted from the laser diode 22 and the additional laser diodes 28 to generate mixed light. For this purpose, the beam combiner 29 has a radiation inlet side 35 facing the radiation outlet side 36 of the optical element 25. Further, the beam combiner 29 has a radiation outlet side 36 from which the mixed light exits the beam combiner 29. The beam combiner 29 may be connected to the optical element 25 via a connecting member such as silicone.

[0057] Furthermore, the semiconductor laser 20 includes three monitoring diodes 42. Each of the monitoring diodes 42 is assigned to one of the laser diodes 22, 28. The monitoring diodes 42 are disposed on the side opposite to the facet 23 of the laser diodes 22, 28. The monitoring diodes 42 are arranged to detect the laser radiation emitted on the side opposite to the facet 23. Thus, the intensity of the laser radiation emitted by the laser diodes 22, 28 can be roughly determined. This is advantageous, for example, when the semiconductor laser 20 is used for applications used by humans. It is possible to avoid an intensity that is too high and harmful to the eyes.

[0058] On the side opposite to the facets 23 of the laser diode 22 and the further laser diode 28, an additional heat sink having high thermal conductivity and capable of dissipating heat from the laser diode 22 and the further laser diode 28 can be arranged. The heat sink is not shown.

[0059] FIG. 5B is a cross-sectional view through the semiconductor laser 20 along line AA of FIG. 5A. The laser diodes 22 and two further laser diodes 28 are arranged adjacent to each other in the lateral direction x. The optical element 25 has the shape of a quarter sphere. The beam combiner 29 covers the three optical elements 25. The molded body 27 completely surrounds the laser diode 22, the further laser diode 28, the carrier 21, and the beam combiner 29 in the lateral direction x. The side opposite to the substrate 32 of the beam combiner 29 is open from the molded body 27.

[0060] The beam combiner 29 has a radiation exit surface 43. The radiation exit surface 43 of the beam combiner 29 is arranged adjacent to the laser diode 22 and the two further laser diodes 28 in the lateral direction x. The radiation exit surface 43 of the beam combiner 29 is smaller than the lateral extension of the beam combiner 29. Since the beam combiner 29 is open from the molded body 27 on the side opposite to the substrate 32, the radiation exit surface 43 of the beam combiner 29 forms the radiation exit surface 43 of the semiconductor laser 20. The semiconductor laser 20 is configured to emit mixed light, particularly white mixed light, through the radiation exit surface 43.

[0061] FIG. 5C is a cross-sectional view through the semiconductor laser 20 along line BB of FIG. 5A. The further laser diode 28 having the carrier 21 and the optical element 25 has the structure of the laser diode 22 shown in FIGS. 1 and 2. The monitoring diode 42 is arranged on the side opposite to the facet 23. The further laser diode 28, the optical element 25, the carrier 21, the beam combiner 29, and the monitoring diode 42 are completely surrounded by the molded body 27 in the lateral direction x.

[0062] A through-connection portion 41 extends from the upper surface 37 of the molded body 27 on the side opposite to the substrate 32 through the molded body 27 toward the substrate 32. The connection carrier 31 is not shown. The through-connection portion 41 further penetrates the substrate 32 from the side facing the molded body 27 and extends to the lower side 44 of the substrate 32 on the side opposite to the molded body 27. The through-connection portion 41 contains a conductive material. The electrical contact 38 is disposed on the upper surface 37 of the molded body 27, and the contact is electrically connected to the through-connection portion 41. Through the through-connection portion 41, the electrical contact 38 disposed on the upper surface 37 of the molded body 27 is electrically connected to the electrical contact 38 disposed on the lower side 44 of the substrate 32. Further, the through-connection portion 41 is electrically connected to the carrier 21 via the substrate 32, and thus to the laser diodes 22, 28. If a number of electrical contacts 38 are required, for example, to contact the laser diodes 22, 28 and the monitoring diode 42, it is advantageous to dispose the electrical contacts 38 on both the upper surface 37 of the molded body 27 and the lower side 44 of the substrate 32. However, it is also possible to dispose the electrical contacts 38 only on the upper surface 37 of the molded body 27 or only on the lower side 44 of the substrate 32.

[0063] FIG. 6 is a diagram showing the energy distribution of the laser radiation emitted from the radiation exit side 36 of the semiconductor laser 20 according to an exemplary embodiment. On the x-axis, the lateral extension in the lateral direction x is plotted in millimeters. On the y-axis, a further lateral extension orthogonal to the lateral direction x is plotted in millimeters. The colored z component indicates the intensity of the laser radiation emitted by the semiconductor laser 20 at the radiation exit side 36. The intensity of the laser radiation is highest at the center of the radiation exit surface 43. The semiconductor laser 20 is the exemplary embodiment shown in FIG. 4.

[0064] This patent application claims the priority of German Patent Application No. 102018117518.3, the disclosure of which is incorporated herein by reference.

[0065] The present invention is not limited to exemplary embodiments by way of detailed description based on detailed description. Rather, the present invention includes such features and any combination thereof, even if the novel features or combinations of features themselves are not explicitly described in the claims or exemplary embodiments, and in particular includes any combination of the features described in the claims.

Explanation of Signs

[0066] 20 Semiconductor laser 21 Carrier 22 Laser diode 23 Facet 24 Radiation exit region 25 Optical element 26 Connection member 27 Formed body 28 Further laser diode 29 Beam combiner 30 Conversion element 31 Connection carrier 32 Substrate 33 Bonding wire 34 ESD element 35 Radiation inlet side 36 Radiation exit side 37 Upper surface 38 Electrical contact 39 Side surface 40 Mirror layer 41 Through connection part 42 Monitoring diode 43 Radiation exit surface 44 Lower side x Lateral direction

Claims

1. - Career (21) and an edge-emitting laser diode (22) arranged on said carrier (21) and having a facet (23) with an active area for generating laser radiation and a radiation exit area (24); an optical element (25) covering said facet (23); a connecting member (26) arranged between said optical element (25) and said facet (23), said facet (23) being free from said connecting member (26) in said radiation exit area (24); a molding (27) at least partially covering said laser diode (22) and said optical element (25); Equipped with - said optical element (25) is at least partially transparent to the laser radiation emitted by said laser diode (22) during operation; - said optical element (25) is configured to change the main propagation direction of the laser radiation incident on said optical element (25) during operation; A semiconductor laser (20).

2. 2. The semiconductor laser (20) according to claim 1, wherein the connecting member (26) is arranged around the radiation exit area (24) and encapsulates the radiation exit area (24) together with the optical element (25).

3. The water vapor transmission rate through the connecting member (26) is at most 1×10 －３ g / m ２ 3. The semiconductor laser (20) according to claim 1 or 2, wherein the laser power is 100 watts / day.

4. The semiconductor laser (20) of claim 1 , wherein the connecting member (26) comprises an inorganic material.

5. The semiconductor laser (20) of any one of claims 1 to 4, wherein the connecting member (26) comprises a plastic.

6. The semiconductor laser (20) of any one of claims 1 to 5, wherein the connecting member (26) comprises an epoxy or a polymer of carbon-containing structural units.

7. The semiconductor laser (20) according to any one of the preceding claims, wherein the molding (27) completely covers the laser diode (22) at least on one side.

8. The semiconductor laser (20) according to any one of claims 1 to 7, wherein a main emission direction of the laser diode (22) is transverse or perpendicular to the main emission direction of the semiconductor laser (20).

9. 9. The semiconductor laser (20) according to claim 1, wherein the carrier (21) is at least partially surrounded by the molding (27) in a lateral direction (x), the lateral direction (x) being parallel to a main extension plane of the carrier (21).

10. 10. The semiconductor laser (20) according to claim 1, having a radiation exit face (43) open from the shaped body (27).

11. The semiconductor laser (20) according to any one of the preceding claims, wherein the optical element (25) completely covers the facet (23).

12. The semiconductor laser (20) according to any one of the preceding claims, wherein an anti-reflection layer is applied to the side of the optical element (25) facing the radiation exit area (24).

13. 13. The semiconductor laser (20) according to any one of the preceding claims, wherein the optical element (25) has a radiation exit side (36) to which an antireflection layer is further applied.

14. The semiconductor laser (20) according to any one of the preceding claims, wherein the optical element (25) is designed to shape the laser radiation incident on the optical element (25) during operation.

15. The semiconductor laser (20) according to any one of the preceding claims, comprising two further edge-emitting laser diodes (28), each arranged on a carrier (21).

16. A beam combiner (29), the beam combiner (29) is designed to mix the laser radiation emitted by the laser diode (22) and the two further laser diodes (28); 16. The semiconductor laser (20) according to claim 15, wherein the radiation exit face of the beam combiner (29) forms a radiation exit face of the semiconductor laser (20).

17. 17. The semiconductor laser (20) according to claim 16, wherein the molding (27) completely covers the laser diode (22), the two further laser diodes (28), the carrier (21) and the beam combiner (29) in the lateral direction (x).

18. 18. The semiconductor laser (20) according to claim 16 or 17, wherein the semiconductor laser (20) comprises three optical elements assigned to the laser diode (22) and to the two further laser diodes (28), and the beam combiner (29) is arranged downstream of the optical elements.

19. 17. The semiconductor laser (20) according to any one of claims 11 to 16, wherein the laser diode (22) and the two further laser diodes (28) are designed to generate laser radiation in different wavelength ranges during operation.

20. 20. The semiconductor laser (20) according to any one of the preceding claims, wherein the optical element (25) is followed by a conversion element (30) designed to convert the wavelength of the radiation emitted by the laser diode (22) during operation.

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