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 technology]

[0001] A semiconductor laser is identified. Summary of the Invention [Problem to be solved by the invention]

[0002] An object of this disclosure is to identify semiconductor lasers that can be operated efficiently. [Means for solving the problem]

[0003] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser comprises a carrier. The carrier can be a so-called submount. The carrier can be a three-dimensional body, for example, having the shape of a cylinder, a disk, or a cube. 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 top surface, of the carrier. The carrier can comprise a semiconductor material.

[0004] The carrier may include a driver capable of controlling the semiconductor laser, or it may represent an electronically passive component and serve only as an packaging level.

[0005] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser is comprised of an edge-emitting laser diode arranged on a carrier, having an active region for generating laser radiation and a facet with an emission exit region. The edge-emitting laser diode is designed, for example, to emit laser radiation 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 comprise a different semiconductor material, for example, based on the III-V semiconductor material system. The laser diode can be disposed on the top surface of the carrier. The laser diode can be connected to the carrier via electrical contacts, allowing the laser diode to be controlled via the carrier. For example, the laser diode has electrical contacts on the side facing the top surface of the carrier, which are electrically connected to the carrier. Alternatively, the laser diode can be electrically connected to the carrier via bonding wires. The laser diode can also be mechanically attached to the carrier on the top surface.

[0007] The facets are oriented laterally, preferably perpendicular to the main extension plane of the active region. Furthermore, the facets are oriented laterally, preferably perpendicular 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 therefore limited to the facet.

[0008] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser comprises 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. Alternatively, the optical element can completely cover the radiation exit area.

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

[0010] In particular, the connecting member is arranged between the optical element and the facet in such a way that the radiation exit region is as enclosed as possible. This means, for example, that the connecting member is arranged around the radiation exit region. Alternatively, the connecting member can completely cover the facet and encapsulate it. Encapsulating the radiation exit region can mean that the radiation exit region is hermetically encapsulated with respect to the environment of the semiconductor laser. The encapsulation of the radiation exit region protects the radiation exit region 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 connecting member is at most 1×10 -3 g / m 2 / day, preferably at most 3 × 10 -4 g / m 2 / day.

[0011] The connecting member may also include an inorganic material such as glass or metal, a plastic such as silicone, a silicone derivative, a silazane, a siloxane, a polysiloxane, a polysilazane, or a silicone hybrid material, or an epoxy or polymer of carbon-containing structural units.

[0012] According to at least one embodiment of the semiconductor laser of the present invention, the semiconductor laser comprises a molding that at least partially covers the laser diode and the optical element. The molding may be an encapsulant. The molding is designed to protect the laser diode from environmental influences. The molding can be constructed by injection molding, the so-called Dam & Fill process, or a spraying method. For example, the molding comprises 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 transparent to the laser radiation emitted by the laser diode during operation. This means that the laser radiation generated during operation can at least partially pass through the optical element. At the radiation inlet side of the optical element facing the radiation outlet region, at least a portion of the laser radiation emitted by the laser diode can enter the optical element. At the radiation outlet side of the optical element, at least a portion of the laser radiation can exit the optical element. The optical element can comprise sapphire, diamond, SiC, or an organosilicon compound. In particular, the optical element exhibits low absorption of the laser radiation emitted by the laser diode during operation. 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 a main propagation direction parallel to the main extension plane of the carrier, for example. The main propagation direction can also be the beam direction of the laser radiation. The laser radiation emitted by 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 the laser radiation through the optical element, the main propagation direction of the laser radiation is changed. For example, the main propagation direction of the laser radiation emitted by the laser diode is transverse or perpendicular to the main extension plane of the carrier.

[0015] For this purpose, the optical element can have the shape of a segment of a sphere or an ellipsoid, for example the optical element has the shape of a quarter sphere, i.e. 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 comprises a carrier, an edge-emitting laser diode arranged on the carrier and comprising a facet having an active region for generating laser radiation and a radiation exit region, an optical element covering the facet, a connecting member arranged between the optical element and the facet, and a molding at least partially covering the laser diode and the optical element, wherein the optical element is at least partially transparent to the laser radiation emitted by the laser diode during operation, and the optical element is designed to change the main propagation direction of the laser radiation incident on the optical element during operation.

[0017] The semiconductor laser described herein is based on the idea that it can be operated under normal atmospheric conditions without additional hermetic sealing. This means that the sealing and protection of the facet, especially the radiation exit area, is achieved by the connecting member together with the optical elements. Furthermore, the laser diode is encapsulated by a molding. This means that the semiconductor laser does not require a hermetically sealed housing. The optical elements and molding arranged on the facet already protect the laser diode and facet from environmental influences. Therefore, it is not necessary to place 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 facets, the facets are protected against particle deposition from the laser diode's environment. Particle deposition or accumulation on the facets, especially in the radiation exit area, can interact with the emitted laser radiation and cause heating in the facet area. This can lead to the destruction of the laser diode. Deposits on the facets can be decomposed and burned, especially by short-wave radiation. Such changes in the facet area can reduce the decoupling efficiency of the semiconductor laser and, for example, damage the facet coating due to light absorption in the deposits, which can result in overheating. Therefore, sealing the facets with connecting members proves particularly advantageous. Furthermore, semiconductor lasers can be manufactured more cost-effectively and can be installed with reduced installation space requirements.

[0019] The use of optical elements can reduce the beam divergence of the laser radiation emitted by the laser diode. Otherwise, the electric field strength of the divergent beam can act like optical tweezers to attract contaminants that may be near the facet and deposit them on the facet. Thus, reducing the beam divergence directly translates into reducing the deposits.

[0020] Furthermore, the use of optical elements allows for an increased interface with the atmosphere, which reduces the potential deposition per unit area, and also reduces the energy density at this interface compared to the energy density at the direct facet.

[0021] Optical elements also offer the possibility to shape and redirect the laser radiation emerging from the laser diode. In this way, edge-emitting laser diodes can be used in surface-emitting semiconductor lasers.

[0022] The optical element may comprise a material with high thermal conductivity, allowing heat to be dissipated through the optical element, thereby preventing the facet from overheating.

[0023] Because the semiconductor laser already constitutes an optical element, the downstream optics can be made smaller and simpler. Overall, the integration of optics, logic, and sensor technology near the semiconductor laser is simplified due to the reduced installation space.

[0024] Advantageously, the semiconductor lasers can be fabricated in composites that can be separated into individual semiconductor lasers later in the manufacturing process.

[0025] According to at least one embodiment of the semiconductor laser of the present invention, the molding completely covers the laser diode on at least one side. The molding can completely cover the laser diode on the side opposite the carrier. It is also possible for the molding to completely cover the laser diode on the side facing laterally or perpendicularly to the main extension plane of the carrier. In particular, the molding can completely cover the laser diode on at least one side so that the molding encapsulates the laser diode. The molding can serve to protect the laser diode from environmental influences from the semiconductor laser's environment. Due to the molding and other elements surrounding the laser diode, such as the carrier, the laser diode is not in direct contact with the semiconductor laser's environment. The molding can at least partially be in direct contact with the laser diode. In this way, the molding can be molded directly onto the laser diode. Furthermore, the use of the molding eliminates the need for a surrounding housing with a cavity for accommodating the laser diode to protect the laser diode from environmental influences from the semiconductor laser's environment.

[0026] According to at least one embodiment of the semiconductor laser of the present invention, the main emission direction of the laser diode is transverse or perpendicular 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 radiation emitted by the laser diode during operation. Furthermore, the main emission direction of the semiconductor laser corresponds to the main propagation direction of the laser radiation emitted by the semiconductor laser during operation. This means that the main propagation direction of the laser radiation emitted by the semiconductor laser during operation is changed by passing the laser radiation through an optical element transverse or perpendicular to the main propagation direction of the semiconductor laser. For example, the main emission direction of the semiconductor laser extends opposite to the carrier. In this way, edge-emitting laser diodes can be advantageously used in surface-emitting semiconductor lasers.

[0027] Furthermore, the main radiation direction of the semiconductor laser can be parallel to the lateral direction parallel to the main extension plane of the carrier, but not parallel to the main radiation direction of the laser diode, so that the laser radiation can be coupled out laterally from the semiconductor laser.

[0028] To change the main propagation direction of the laser radiation, the optical element may have a diffractive optical structure, for example, the diffractive optical element is arranged on the radiation entrance side and / or on the radiation exit side of the optical element, and the diffractive optical element may be designed to match the shape of the laser radiation.

[0029] According to at least one embodiment of the semiconductor laser of the present invention, the carrier is at least partially laterally surrounded by the molding, with the lateral direction being parallel to the main extension plane of the carrier. This can mean that the side surfaces of the carrier that are transverse or perpendicular to the main extension plane of the carrier are at least partially covered by the molding. The molding may be in partial direct contact with the carrier. Alternatively, the carrier may be completely surrounded by the molding in the lateral direction. In this way, the carrier and the laser diode are encapsulated by the molding and can be 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 molded 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 mold and subsequently cured. In particular, the term casting process includes casting, injection molding, transfer molding, and compression molding. Thus, the molded body can be molded into a laser diode. The molded body can comprise a molding compound. The molded body formed by a 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 an emission exit surface that is open from the molding. The emission exit surface can be arranged on the side of the semiconductor laser opposite the carrier. The emission exit surface can have a main extension surface that is parallel to a main extension surface of the carrier. The emission exit surface can also be curved or non-planar. The emission exit surface of the semiconductor laser can be the emission exit surface of an optical element. Alternatively, the emission exit surface of the semiconductor laser can be the emission exit surface of a component of the semiconductor laser downstream of the optical element. Therefore, the molding does not need to be transparent to the laser radiation emitted by 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 of the optical element facing the facet is at least as large 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 element. In this way, the optical element seals the facet against environmental influences from the semiconductor laser's environment.

[0033] According to at least one embodiment of the semiconductor laser of the present invention, an anti-reflection layer is applied to the optical element on the side facing the radiation exit area. The optical element may have a radiation entrance side facing the radiation exit area. The radiation entrance side of the optical element may have a reflectivity of 0.5% or more, or 0.1% or more, for the laser radiation emitted by the laser diode. This can prevent or reduce feedback of reflected laser radiation back into the laser diode. 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 to which an anti-reflection layer is further applied. Laser radiation incident on the optical element can be deflected within the optical element so that the laser radiation leaves the optical element at 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% for the laser radiation emitted by the laser diode. Therefore, losses in 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 to support the decomposition reaction on the radiation exit side. The photocatalytic layer is configured to remove and / or decompose deposits on the radiation exit side upon laser irradiation. In this way, the photocatalytic layer influences 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. If the photocatalytic layer contains a metal, it preferably has a thickness of 10 nm or less, 5 nm or less, or 3 nm or less so that the laser radiation can pass through the photocatalytic layer without significant loss. In this way, applying a photocatalytic layer to the radiation exit side of the optical element can reduce or prevent the accumulation of undesired materials.

[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. It is also possible that the optical element is designed to change other parameters of the laser radiation, such as the beam divergence. 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 mirror layer constructed from a metal mirror layer, a dielectric mirror layer, or a combination of a metal mirror and a dielectric mirror. One or more mirror layers may be arranged on the surface of the optical element. Furthermore, the optical element may have one or more masks for shaping the laser radiation. The use of an optical element designed to shape the laser radiation allows for more compact and simpler downstream optics.

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

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

[0039] By using a laser diode and two more laser diodes, mixed light can be generated, and because the laser can emit in three different colors, e.g., 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 arranged downstream of three optical elements: a laser diode and two additional laser diodes. The beam combiner is designed to mix the laser radiation emitted by the laser diode and the two additional laser diodes to generate mixed light. For example, the beam combiner has an input side through which the laser radiation exiting the optical elements enters the beam combiner during operation. The beam combiner may also have an output side through which the mixed light exits the beam combiner. For example, the beam combiner is connected to the optical elements by a connecting member, e.g., silicone. The output surface of the beam combiner can form the output surface of the semiconductor laser. Advantageously, in this way, the semiconductor laser can emit mixed light, e.g., white mixed light.

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

[0042] The semiconductor lasers described herein are explained in more detail below in conjunction with exemplary embodiments and corresponding figures. [Brief explanation of the drawings]

[0043] [Figure 1] FIG. 1 is a schematic cross-sectional view through a semiconductor laser according to an exemplary embodiment. [Figure 2] FIG. 2 is a top view of a semiconductor laser according to an exemplary embodiment. [Figure 3] FIG. 3 is a schematic cross-sectional view through a semiconductor laser according to an exemplary embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view through a semiconductor laser according to an exemplary embodiment. [Figure 5A] FIG. 5A is a diagram of a semiconductor laser according to an example embodiment. [Figure 5B] FIG. 5B is a diagram of a semiconductor laser according to an example embodiment. [Figure 5C] FIG. 5C is a diagram of a semiconductor laser according to an example embodiment. [Figure 6] FIG. 6 is a diagram illustrating the energy distribution of laser radiation emerging at the radiation exit side of a semiconductor laser according to an exemplary embodiment.

[0044] In the figures, identical, similar or equivalent elements are provided with the same reference numerals. The figures and the proportions of the elements therein are not to be considered as true to scale relative to one another. Rather, the size of individual elements may be increased for easier representation and / or understanding. DETAILED DESCRIPTION OF THE INVENTION

[0045] FIG. 1 shows a semiconductor laser 20 according to an exemplary embodiment. The semiconductor laser 20 comprises a carrier 21 having an elongated 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 with a radiation exit region 24. During operation, the laser radiation generated by the laser diode 22 has a main propagation direction parallel to the main extension plane of the carrier 21. The semiconductor laser 20 further comprises an optical element 25. The optical element 25 completely covers the facet 23 and the radiation exit region 24. The optical element 25 is disposed adjacent to the laser diode 22 in the lateral direction x, which is parallel to the main extension plane 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. The other flat outer surface of the quarter sphere faces away from the carrier 21.

[0046] A connecting element 26 is arranged between the optical element 25 and the facet 23. The optical element 25 is mechanically connected to the facet 23 via the connecting element 26. The optical element 25 is partially transparent 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. Furthermore, the optical element 25 has a radiation outlet side 36 facing away from the carrier 21. The optical element 25 is thus 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 perpendicular to the main radiation direction of the semiconductor laser 20. Furthermore, the main propagation direction of the laser radiation emitting at the radiation outlet side 36 is perpendicular to the main radiation direction of the laser diode 22.

[0047] The semiconductor laser 20 also has a molding 27 that at least partially covers the laser diode 22 and the optical element 25. The molding 27 surrounds the laser diode 22, the carrier 21, and the optical element 25 in the lateral direction x. The molding 27 thus completely covers the laser diode 22 with its side surfaces 39, which extend transversely or perpendicularly to the main extension plane of the carrier 21. A top surface 37 of the laser diode 22 facing away from the carrier 21 is open from the molding 27. A radiation exit side 36 of the optical element 25 facing away from the carrier 21 is also open from the molding 27. The radiation exit side 36 has a planar, i.e., non-curved, shape. The molding 27 is formed by a casting and / or injection molding process.

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

[0049] 2 is a top view of a semiconductor laser 20 according to another exemplary embodiment. The molding 27 is not shown in this view. Electrical contacts 38 are disposed on the substrate 32. The electrical contacts 38 are electrically connected to the laser diode 22 and the carrier 21 via bonding wires 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. To this end, the optical element 25 may include a diffractive element. Additionally, a mirror layer 40 is applied to the curved outer surface of the optical element 25. The mirror layer 40 may be metallic or dielectric, or a combination of both.

[0051] An anti-reflective layer may also be applied to the radiation entrance side 35 of the optical element 25. An anti-reflective layer may also be applied to the radiation exit side 36 of the optical element 25. A photocatalytic layer may also be applied to the radiation exit side 36 of the optical element 25 to assist the decomposition reaction at the radiation exit side 36.

[0052] FIG. 3 is a schematic cross-sectional view through a semiconductor laser 20 according to another exemplary embodiment. In contrast to the exemplary embodiment of FIG. 1, the molding 27 covers the laser diode 22 on its top surface 37, facing away from the carrier 21. The laser diode 22 is thus completely encapsulated and protected from environmental influences from the environment of the semiconductor laser 20. No additional housing or cavity is required in which the laser diode 22 is disposed. A feedthrough 41 is arranged in the substrate 32. The feedthrough 41 is filled with an electrically conductive material. The feedthrough 41 extends from the side of the substrate 32 facing away from the carrier 21 toward the carrier 21. An electrical contact 38 is arranged on the side of the substrate 32 facing away from the carrier 21, via which the carrier 21 is electrically connected to the connection carrier 31. The connection carrier 31 is not shown.

[0053] Furthermore, a conversion element 30 is provided behind the optical element 25 for converting the wavelength of the radiation emitted by the laser diode 22 during operation. The conversion element 30 has a radiation inlet side 35 facing the radiation outlet side 36 of the optical element 25. The conversion element 30 also has a radiation outlet side 36 on the top surface 37 of the semiconductor laser 20, facing away from the substrate 32. In this way, the main propagation direction of the laser radiation exiting the optical element 25 does not change significantly when passing through the conversion element 30. Furthermore, 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 transverse direction x, the conversion element 30 is completely surrounded by the molding 27.

[0054] 4 is a schematic cross-sectional view through a 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 by the laser diode 22 during operation. The main propagation direction of the laser radiation exiting the facet 23 of the laser diode 22 is shown to be parallel to the main extension plane of the carrier 21. The optical element 25 is shown to shape and deflect the laser radiation such that the main propagation direction of the laser radiation exiting the optical element 25 is perpendicular to the main extension plane of the carrier 21.

[0055] 5A is a top view of a semiconductor laser 20 according to another exemplary embodiment. The semiconductor laser 20 comprises 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. Furthermore, an optical element 25 covers the facet 23 of each 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 intended to mix the laser radiation emitted by the laser diode 22 and the further laser diode 28 to generate mixed light. For this purpose, the beam combiner 29 has a radiation entrance side 35 facing a radiation exit side 36 of the optical elements 25. Furthermore, the beam combiner 29 has a radiation exit side 36 through which the mixed light leaves the beam combiner 29. The beam combiner 29 may be connected to the optical elements 25 via a connecting member such as silicone.

[0057] Furthermore, the semiconductor laser 20 has three monitor diodes 42. Each of the monitor diodes 42 is assigned to one of the laser diodes 22, 28. The monitor diodes 42 are arranged on the side of the laser diodes 22, 28 opposite the facet 23. The monitor diodes 42 are positioned to detect the laser radiation emitted on the side opposite the facet 23. This allows the intensity of the laser radiation emitted by the laser diodes 22, 28 to be approximately determined. This is advantageous, for example, when the semiconductor laser 20 is used in human applications. This avoids excessive intensities that are harmful to the eyes.

[0058] 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 on the side opposite to the facet 23 of the laser diode 22 and the further laser diode 28. The heat sink is not shown.

[0059] 5B is a cross-sectional view through the semiconductor laser 20 along the line AA in FIG. 5A. The laser diode 22 and two further laser diodes 28 are arranged next 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 molding body 27 completely surrounds the laser diode 22, the further laser diodes 28, the carrier 21, and the beam combiner 29 in the lateral direction x. The side of the beam combiner 29 opposite the substrate 32 is open from the molding body 27.

[0060] The beam combiner 29 has an emission exit surface 43. The emission 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 emission exit surface 43 of the beam combiner 29 is smaller than the lateral extension of the beam combiner 29. The beam combiner 29 is open from the molding 27 on the side facing away from the substrate 32, so that the emission exit surface 43 of the beam combiner 29 forms the emission exit surface 43 of the semiconductor laser 20. The semiconductor laser 20 is configured to emit mixed light, in particular white mixed light, via the emission exit surface 43.

[0061] Figure 5C is a cross-section through the semiconductor laser 20 along the line BB in Figure 5A. The further laser diode 28 with the carrier 21 and the optical element 25 has the structure of the laser diode 22 shown in Figures 1 and 2. The monitoring diode 42 is arranged on the side opposite 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 molding 27 in the lateral direction x.

[0062] A through-connection 41 extends through the molded body 27 from an upper surface 37 of the molded body 27 opposite the substrate 32 towards the substrate 32. The connection carrier 31 is not shown. The through-connection 41 further extends through the substrate 32 from the side facing the molded body 27 to an underside 44 of the substrate 32 opposite the molded body 27. The through-connection 41 comprises an electrically conductive material. An electrical contact 38 is arranged on the upper surface 37 of the molded body 27 and is electrically connected to the through-connection 41. Via the through-connection 41, the electrical contact 38 arranged on the upper surface 37 of the molded body 27 is electrically connected to the electrical contact 38 arranged on the underside 44 of the substrate 32. Furthermore, the through-connection 41 is electrically connected via the substrate 32 to the carrier 21 and thus to the laser diodes 22, 28. If multiple electrical contacts 38 are required, for example, to contact the laser diodes 22, 28 and the monitor diode 42, it is advantageous to place the electrical contacts 38 on both the upper surface 37 of the molding 27 and the underside 44 of the substrate 32. However, it is also possible to place the electrical contacts 38 only on the upper surface 37 of the molding 27 or only on the underside 44 of the substrate 32.

[0063] 6 shows the energy distribution of the laser radiation emitting from the radiation exit side 36 of the semiconductor laser 20 according to an exemplary embodiment. On the x-axis, the lateral extension in millimeters in the lateral direction x is plotted. On the y-axis, the further lateral extension perpendicular to the lateral direction x is plotted in millimeters. The colored z-component indicates the intensity of the laser radiation emitting from 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 face 43. The semiconductor laser 20 is the exemplary embodiment shown in FIG. 4.

[0064] This patent application claims priority from German patent application 102018117518.3, the disclosure of which is incorporated herein by reference.

[0065] The present invention is not limited to the exemplary embodiments by the detailed description provided herein, but rather includes any feature and any combination thereof, and particularly any combination of features recited in the claims, even if the novel feature or combination of features itself is not explicitly recited in the claims or exemplary embodiments. [Explanation of symbols]

[0066] 20 Semiconductor laser 21 Career 22 Laser diode 23 Facets 24 Radiation exit area 25 Optical Elements 26 Connecting member 27 Molded body 28 More Laser Diodes 29 Beam Combiner 30 conversion element 31 Connecting Carriers 32 PCB 33 Bonding Wire 34 ESD elements 35 Radiation inlet side 36 Radiation outlet side 37 Top 38 Electrical Contacts 39 Side 40 mirror layer 41 Through-connection 42 Monitoring diode 43 Radiation exit surface 44 Lower side x horizontal 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 region for generating laser radiation and a radiation exit region (24); an optical element (25) covering said facet (23); a connecting member (26) arranged between the optical element (25) and the facet (23), the connecting member (26) being arranged around the radiation exit area (24) and the facet (23) not being covered by the connecting member (26) in the 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) 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 W / day.

4. The semiconductor laser (20) according to any one of claims 1 to 3, 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 plastic.

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

7. 7. The semiconductor laser (20) according to claim 1, wherein the molding (27) completely covers the laser diode (22) on at least one side.

8. 8. The semiconductor laser (20) according to any one of claims 1 to 7, wherein the 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 surface (43) that is not covered by the shaped body (27).

11. The semiconductor laser (20) according to any one of claims 1 to 10, wherein the optical element (25) completely covers the facet (23).

12. 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 anti-reflection layer is further applied.

14. 14. The semiconductor laser (20) according to any one of claims 1 to 13, wherein the optical element (25) is designed to shape the laser radiation incident on the optical element (25) during operation.

15. 15. The semiconductor laser (20) according to any one of claims 1 to 14, 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 the 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 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 claim 15 or 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 claims 1 to 19, 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.

Images