Edge emitting semiconductor laser and method for producing an edge emitting semiconductor laser

Abstract

The invention relates to an edge emitting semiconductor laser. The edge emitting semiconductor laser comprises a first semiconductor layer having a first conductivity type, a second semiconductor layer having a second conductivity type, and an active region arranged between the first semiconductor layer and the second semiconductor layer and designed to generate electromagnetic radiation. The edge emitting semiconductor laser further comprises a contact layer for electrically contacting the first semiconductor layer, and a grating structure having a plurality of structures which are arranged at a distance from one another. The contact layer is arranged on the side of the first semiconductor layer facing away from the active region, and the grating structure is arranged between the first semiconductor layer and the contact layer. The invention furthermore relates to a method for producing an edge emitting semiconductor laser.

Description

[0001] 2024PF00797 10 . September 2025

[0002] P2024 , 0728 WO N

[0003] - 1 -

[0004] Description

[0005] Edge-emitting semiconductor laser and method for manufacturing an edge-emitting semiconductor laser

[0006] An edge-emitting semiconductor laser and a method for manufacturing an edge-emitting semiconductor laser are described.

[0007] One problem to be solved is to specify an edge-emitting semiconductor laser that can be operated with particular efficiency. Another problem to be solved is to specify a method by which an edge-emitting semiconductor laser that can be operated with particular efficiency can be manufactured.

[0008] According to at least one embodiment, the edge-emitting semiconductor laser comprises a first semiconductor layer. The edge-emitting semiconductor laser will also be referred to as a semiconductor laser in the following. The first semiconductor layer exhibits a first conductivity type. The fact that the first semiconductor layer exhibits a first conductivity type can mean that the first semiconductor layer is n-type or p-type, for example, that it is doped accordingly.

[0009] The first semiconductor layer is based, for example, on a II-IV compound semiconductor material. For instance, the first semiconductor layer may have or be made of gallium nitride (GaN), gallium arsenide (GaAs), AlInGaN, AlInGaP, and / or AlInGaAs. The first semiconductor layer may, in particular, be p-doped. For example, the 2024PF00797 (September 10, 2025)

[0010] P2024 , 0728 WO N

[0011] 2. The first semiconductor layer contains p-doping materials and / or is p-conducting.

[0012] The first semiconductor layer can be thin. This can mean that the thickness of the first semiconductor layer is, for example, a maximum of 50 pm, a maximum of 20 pm, a maximum of 5 pm, or a maximum of 2 pm.

[0013] According to at least one embodiment, the edge-emitting semiconductor laser has a second semiconductor layer. This second semiconductor layer has a second conductivity type. The second semiconductor layer can be based on a II-IV compound semiconductor material. For example, the second semiconductor layer may have or be made of gallium nitride (GaN), gallium arsenide (GaAs), AlInGaN, AlInGaP, and / or AlInGaAs.

[0014] The second conductivity type can be different from the first conductivity type. In other words, the doping of the second semiconductor layer can be the opposite of that of the first semiconductor layer. For example, the second semiconductor layer might be n-doped. The first semiconductor layer might contain n dopants and / or be n-conducting. Alternatively, it is also possible for the first semiconductor layer to be n-doped and the second semiconductor layer to be p-doped.

[0015] According to at least one embodiment, the semiconductor laser has an active region. The active region is located between the first and second semiconductor layers. The active region can be used to generate electromagnetic radiation, in particular 2024PF00797 10 September 2025

[0016] P2024 , 0728 WO N

[0017] 3

[0018] Laser radiation must be set up. The electromagnetic radiation can be in the visible, UV, and / or IR range of the electromagnetic spectrum. For example, the active region may have a pn junction and / or a quantum well structure.

[0019] The semiconductor laser can have a semiconductor layer sequence. This sequence may include, for example, the first semiconductor layer, the second semiconductor layer, and the active region, or be formed from these layers. In other words, the first semiconductor layer, the second semiconductor layer, and / or the active region can be layers of the semiconductor laser's layer sequence. The layers of the semiconductor layer sequence can be at least partially epitaxially grown.

[0020] The layers can have a thickness. This thickness can be, for example, the extent along a stacking direction of the semiconductor layer sequence. The layers are arranged sequentially along the stacking direction. A principal extent direction, or principal extent plane, of the semiconductor laser, for example, runs perpendicular to the stacking direction.

[0021] It is also possible that the first semiconductor layer and / or the second semiconductor layer is a first or second semiconductor layer sequence, respectively. In other words, the first semiconductor layer and / or the second semiconductor layer could, for example, comprise at least two layers. 2024PF00797 September 10, 2025

[0022] P2024 , 0728 WO N

[0023] - 4 -

[0024] According to at least one embodiment, the semiconductor laser has a contact layer for electrically contacting the first semiconductor layer. The contact layer is configured, for example, to induce current in the first semiconductor layer. For instance, the contact layer is located on the side of the first semiconductor layer facing away from the active region. It is possible that the contact layer is in direct contact with the first semiconductor layer, at least partially or exclusively in certain areas, i.e., for example, that it borders directly on the first semiconductor layer in certain areas.

[0025] The contact layer contains, for example, at least one transparent conductive oxide (TCO), or consists of one or more TCOs. For example, the contact layer contains or is composed of indium tin oxide (ITO).

[0026] The thickness of the contact layer is, for example, at least 5 nm, at least 10 nm, or at least 200 nm. The thickness of the contact layer can be at least approximately 200 nm. It is possible for the thickness of the contact layer to be at most 2 pm. For example, the thickness of the contact layer is in a range from 10 nm inclusive to 500 nm inclusive, particularly in a range from 100 nm inclusive to 250 nm inclusive. The thickness of the contact layer can, for example, be 200 nm. The thickness of the contact layer is an extension of the contact layer in a direction perpendicular or at least approximately perpendicular to the principal extension plane of the edge-emitting semiconductor laser. The contact layer can be 2024PF00797 10 September 2025

[0027] P2024 , 0728 WO N

[0028] 5. exhibit a low contact resistance to a semiconductor. For example, the contact resistance is a maximum of 10. -5 Ohm / cm 2 , for example a maximum of 10 -4 Ohm / cm 2 or in particular, a maximum of 1000 -2 Ohm / cm 2 .

[0029] According to at least one embodiment, the semiconductor laser has a lattice structure with a plurality of structures. The structures can be spaced apart from one another. The lattice structure can be an interference grating or an interference filter, for example, a one-dimensional interference grating, or be formed from one. The structures can have a principal direction of extension. For example, the structures are strip-shaped in plan view. The spaced-apart structures of the lattice structure can be parallel or at least approximately parallel to each other. This can mean that the principal directions of extension of the structures are parallel to each other. In other words, the structures have a common principal direction of extension.

[0030] The lattice structure or structures can consist of a metal, a dielectric material, a semiconductor material, and / or an organic material. It is also possible for the lattice structure or structures to consist of at least one of these materials. For example, all structures may be formed from or contain the same material.

[0031] According to at least one embodiment of the semiconductor laser, the lattice structure between the first semiconductor layer is 2024PF00797 10 September 2025

[0032] P2024 , 0728 WO N

[0033] - 6 - and the contact layer. Alternatively or additionally, it is also possible that the lattice structure is arranged between the semiconductor layer sequence of the semiconductor laser and the contact layer. The lattice structure can be adjacent to the semiconductor layer sequence, the first semiconductor layer, and / or the contact layer, in particular directly adjacent to it. For example, the lattice structure is arranged directly between the first semiconductor layer and the contact layer. The lattice structure can thus be arranged, for example, within an optical resonator of the edge-emitting semiconductor laser.

[0034] In at least one embodiment, the edge-emitting semiconductor laser comprises a first semiconductor layer exhibiting a first conductivity type, a second semiconductor layer exhibiting a second conductivity type, an active region located between the first and second semiconductor layers and configured to generate electromagnetic radiation, a contact layer for electrically connecting the first semiconductor layer, and a lattice structure with a plurality of spaced-apart structures. The contact layer may be located on the side of the first semiconductor layer facing away from the active region. The lattice structure is, for example, located between the first semiconductor layer and the contact layer.

[0035] The edge-emitting semiconductor laser is, for example, a DFB laser (Distributed Feedback Laser), i.e., a laser with distributed feedback. This can mean that the semiconductor laser is configured to use the grating structure to 2024PF00797 10 September 2025

[0036] P2024 , 0728 WO N

[0037] - 7 -

[0038] to select the wavelength at which the main emission of the semiconductor laser takes place.

[0039] It is possible that the semiconductor laser, through coupling to the lattice structure, for example by optical coupling, emits electromagnetic radiation spectrally monomode on a single optical mode. The side mode suppression of the semiconductor laser can be at least 30 dB, for example at least 40 dB or at least 50 dB.

[0040] If such a lattice structure is arranged, for example, directly between the first semiconductor layer and an electrical contact, in particular a non-transparent electrical contact, such as a metallization, the efficiency of the semiconductor laser may be reduced by absorption at the electrical contact.

[0041] One principle of semiconductor lasers is to improve the overlap between the electromagnetic radiation of the semiconductor laser's optical field and the grating structure. This overlap of the optical field and the grating structure, for example, improves the coupling of the semiconductor laser's optical field to the grating structure. Simultaneously, the contact layer, particularly the transparent contact layer, can minimize or even reduce the absorption of electromagnetic radiation.

[0042] The edge-emitting semiconductor laser can exhibit improved wavelength stability across current and temperature. The wavelength can also be better controlled, for example, via a wafer with a multitude of semiconductor lasers. 2024PF00797 10 September 2025

[0043] P2024 , 0728 WO N

[0044] - 8 - and thereby differences in wavelength between the semiconductor lasers or different wafers are avoided or at least reduced. The edge-emitting semiconductor laser can also exhibit an improved, i.e., smaller, spectral width and an improved, i.e., longer, coherence length.

[0045] According to at least one embodiment, the semiconductor laser is a DFB laser, and the grating structure is configured to select a wavelength of the main emission of the semiconductor laser. For example, the grating structure is configured for refractive index coupling, absorption coupling, and / or current path modulation. In particular, the grating structure is configured for refractive index coupling, absorption coupling, and / or current path modulation of the electromagnetic radiation of the optical field. That the grating structure is configured for current path modulation can, in particular, mean that the grating structure is configured for gain coupling or gain modulation via current path modulation.

[0046] The grating structure can be configured to modulate the refractive index (n), absorptivity (alpha), and / or gain of the semiconductor laser. The refractive index can be the effective refractive index of the semiconductor laser. The grating structure is configured, for example, to select a specific wavelength, such as a longitudinal wavelength. The main emission of the semiconductor laser can then occur at this wavelength. 2024PF00797 September 10, 2025

[0047] P2024 , 0728 WO N

[0048] 9

[0049] According to at least one embodiment of the semiconductor laser, the contact layer is transparent. The contact layer has, for example, a transparency of at least 50%, at least 70%, at least 80%, or at least 90%. The contact layer can exhibit this transparency, in particular, for a specific wavelength or wavelength range of the electromagnetic radiation generated by the active region.

[0050] According to at least one embodiment, the lattice structure incorporates a metal. In particular, the structures of the lattice structure can contain a metal or be formed from at least one metal. The refractive index, electrical conductivity, and / or absorptivity of the lattice structure can differ from the electrical conductivity, refractive index, and / or absorptivity of the first semiconductor layer, the second semiconductor layer, the active region, and / or the contact layer.

[0051] For example, the metal exhibits absorption and / or reflection in a wavelength range in which the semiconductor laser emits.

[0052] Depending on the overlap of the light mode with the metal and the absorption and / or reflection, an overall absorption / reflection of the light can result. This can, for example, lead to a coupling factor of the light field to the grating structure, especially a DFB grating structure. The stronger this coupling, the better the single-mode selection and side-mode suppression can typically be. For example, with strong coupling of the light field to the grating structure, the 2024PF00797 10 September 2025

[0053] P2024 , 0728 WO N

[0054] - 10 -

[0055] Absorption may be very high, which can lead to a poorer electro-optical performance of the semiconductor laser.

[0056] For example, the metal contains chromium, titanium, gold and / or germanium, or consists of at least one of these materials.

[0057] According to at least one embodiment, the lattice structure comprises a semiconductor material. For example, the lattice structure comprises a II-IV semiconductor material. The lattice structure, for example, the material of the lattice structure, can have a refractive index that differs from the refractive index of the semiconductor layer sequence of the edge-emitting semiconductor laser. Alternatively or additionally, the electrical conductivity and / or absorptivity of the lattice structure, for example, the semiconductor material of the lattice structure, can differ from that of the semiconductor layer sequence, from the layers of the semiconductor layer sequence, and / or from that of the contact layer.

[0058] The light field can couple to the grating structure via reflection and / or absorption, for example, and emit dominantly on a selected mode via the grating period.

[0059] For example, the lattice structure contains silicon and / or carbon.

[0060] According to at least one embodiment, the lattice structure incorporates a dielectric material. In particular, the structures of the lattice structure can incorporate or be formed from the dielectric material. 2024PF00797 10 September 2025

[0061] P2024 , 0728 WO N

[0062] - 11 - Dielectric material, for example, exhibits only low electrical conductivity. The electrical conductivity of the dielectric material is particularly lower than the electrical conductivity of the contact layer and / or the first semiconductor layer. This can mean that fewer charge carriers penetrate the first semiconductor layer through regions where a lattice structure is arranged than in the spaces between adjacent structures. The lattice structure can then be configured for current path modulation. Coupling of the light field to the lattice structure can then be achieved, for example, via charge carrier modulation or varied pumping of the active region.

[0063] For example, the dielectric material is silicon nitride, SiN, silicon oxide, SiO2, aluminum oxide, A1O, and / or MgF, or the dielectric material may, for example, contain at least one of these materials.

[0064] According to at least one embodiment, the lattice structure incorporates an organic material. This organic material may exhibit absorption and / or reflection, particularly in a wavelength range where the semiconductor laser emits. For example, it is possible that the organic material exhibits absorption in the visible and / or IR wavelength range.

[0065] According to at least one embodiment of the semiconductor laser, the lattice structure partially overlaps with the optical field of the semiconductor laser. For example, the thin first semiconductor layer allows the lattice structure to be positioned closer to the optical field of the edge-emitting semiconductor laser 2024PF00797 (September 10, 2025).

[0066] P2024 , 0728 WO N

[0067] - 12 - can be arranged. Alternatively or additionally, the semiconductor layer sequence of the edge-emitting semiconductor laser, in particular the epitaxial semiconductor layer sequence, can be designed such that the optical field, also referred to as the light field, can be guided, or is guided, at a smaller distance to a top surface of the semiconductor laser. This is achieved, for example, by adjusting the semiconductor materials and / or the layer thicknesses of the first semiconductor layer, the second semiconductor layer, and / or the active region. However, it is also possible to introduce further layers into the edge-emitting semiconductor laser or to adjust these layers in order to guide the optical field closer to the top surface of the semiconductor laser.

[0068] The top side of the semiconductor laser can be, in particular, the side of the edge-emitting semiconductor laser where the first semiconductor layer and / or the waveguide is located. In other words, the top side of the semiconductor laser is, for example, located on the side of the semiconductor laser facing away from the substrate.

[0069] For example, the grating structure is completely or partially enclosed by the optical field. The grating structure is thus, for instance, arranged within the optical resonator of the edge-emitting semiconductor laser, in particular an oscillating edge-emitting semiconductor laser. This allows the modulation of the electromagnetic radiation by means of the grating structure to be carried out, for example, in a region of the laser where a higher light intensity of the optical field is desired. (2024PF00797 10 September 2025)

[0070] P2024 , 0728 WO N

[0071] - 13 -

[0072] The field is present, for example, on the top side of the semiconductor laser.

[0073] Due to the overlap of the optical field with the grating structure, the electromagnetic radiation emitted by the edge-emitting semiconductor laser can be efficiently influenced, controlled and / or adjusted by the grating structure.

[0074] According to at least one embodiment, the semiconductor laser has a bridge waveguide. The grating structure is arranged, for example, in the region of the bridge waveguide on the first semiconductor layer. It is possible that the grating structure is arranged exclusively in the region of the bridge waveguide on the first semiconductor layer. Alternatively, the grating structure can extend beyond the bridge waveguide, for example, in a lateral direction. The grating structure can have an extent that corresponds at least approximately to the extent of the bridge waveguide. Alternatively or additionally, it is possible that the grating structure extends over at least 50%, at least 70%, for example, at least 80%, or at least 90% of the bridge waveguide along the main direction of extension of the bridge waveguide.

[0075] According to at least one embodiment, the structures have a principal extension direction that is perpendicular to a principal extension direction of the bridge waveguide. For example, the structures follow one another along the principal extension direction of the bridge waveguide. An extension of the structures along their principal extension direction, for example, a length of the structures, can correspond to an extension of the bridge waveguide in 2024PF00797 10 September 2025

[0076] P2024 , 0728 WO N

[0077] 14. A direction perpendicular to the principal direction of extension of the bridge waveguide, for example, a width of the bridge waveguide, corresponds at least approximately. For example, the structures then terminate flush with the bridge waveguide. However, it is also possible that the length of the structures, or at least of one structure, is less than or greater than the width of the bridge waveguide. For example, the length of the structures lies in a range of 20% to 180% inclusive, for example, in a range of 60% to 140% inclusive, or for example, in a range of 80% to 120% inclusive of the width of the bridge waveguide.

[0078] According to at least one embodiment, the spaces between the structures are filled with the material of the contact layer.

[0079] According to at least one implementation, the lattice structure has a lattice period. The lattice period can be determined from the formula g = — result, where g of the

[0080] Lattice period, X of a wavelength, in particular a vacuum wavelength, of the semiconductor laser and n e ff corresponds to an effective refractive index of a guided light mode. It is also possible that the grating period is an integer multiple of g = — — exhibits or amounts to .

[0081] According to at least one embodiment of the edge-emitting semiconductor laser, the lattice structure has at least two lattice periods. These two lattice periods can be different from each other. This could mean that the lattice structure consists of at least two lattice structures with 2024PF00797 10 September 2025

[0082] P2024 , 0728 WO N

[0083] - 15 - each is formed in a lattice period. The at least two lattice structures or lattice periods of the lattice structure can be arranged next to each other, nested within each other and / or on one or more segments of the semiconductor laser.

[0084] It is possible that the segments of the semiconductor laser with different lattice periods are not electrically connected to each other, and in particular, not directly electrically connected. This can mean that the segments of the semiconductor laser with different lattice periods are assigned to electrically separated segments of the electrical contact and / or the contact layer. "Assigned" in this context can particularly mean that a segment of the semiconductor laser with a different lattice period is electrically conductively connected to a segment of the electrical contact and / or the contact layer.

[0085] Alternatively or additionally, the active region can be cut to define and / or form the segments with different lattice periods, for example by etching. It is also possible that the entire epitaxial structure, i.e., for example, the semiconductor layer sequence or the epitaxially grown semiconductor layer sequence, is cut to separate the segments.

[0086] It is also possible that the lattice structures with their different lattice periods are arranged in different waveguides or laser ridges of the semiconductor laser. For example, the semiconductor laser then has at least two waveguides, which are arranged laterally next to each other. 2024PF00797 September 10, 2025

[0087] P2024 , 0728 WO N

[0088] - 16 -

[0089] The lattice structure can, for example, be a combined lattice. The fact that the lattice structure has at least two lattice periods can mean that the semiconductor laser has at least two wavelengths, in particular at least two vacuum wavelengths. Each lattice period can, for example, be assigned to a wavelength of the edge-emitting semiconductor laser.

[0090] Furthermore, a method for fabricating an edge-emitting semiconductor laser is described. The edge-emitting semiconductor laser described herein is preferably fabricable using a method for fabricating an edge-emitting semiconductor laser described herein. In other words, all features of the method for fabricating an edge-emitting semiconductor laser described herein are also applicable to the edge-emitting semiconductor laser described herein, and vice versa.

[0091] According to at least one embodiment of the method for fabricating an edge-emitting semiconductor laser, the method comprises providing a sequence of semiconductor layers comprising a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, and an active region. The active region may be arranged between the first and second semiconductor layers. For example, the active region is configured to generate electromagnetic radiation.

[0092] According to at least one embodiment, the method comprises the application of a lattice structure with a plurality of structures onto the semiconductor layer sequence. The structures 2024PF00797 10 September 2025

[0093] P2024 , 0728 WO N

[0094] - 17 - can be arranged at intervals from one another. For example, the structures are applied to the semiconductor layer sequence at intervals from one another. Alternatively or additionally, the structures can be created at intervals from one another on the semiconductor layer sequence. For example, the material of the lattice structure can be applied to the entire surface of the first semiconductor layer, for example, only in the area of ​​the waveguide. Subsequently, the material of the lattice structure can be removed in certain areas, for example, in the spaces between the layers, for example, to form the spaces and structures.

[0095] According to at least one embodiment, the method includes the application of a contact layer for electrical contacting the first semiconductor layer onto the lattice structure.

[0096] According to at least one embodiment of the method, a bridge waveguide is formed before the lattice structure is applied. The lattice structure can then be applied to the first semiconductor layer in the region of the bridge waveguide.

[0097] According to at least one embodiment of the method for manufacturing an edge-emitting semiconductor laser, a metallization is applied to the contact layer to form an electrical contact.

[0098] The edge-emitting semiconductor laser and the method for fabricating an edge-emitting semiconductor laser described herein are explained in more detail below, along with exemplary applications and the corresponding figures. 2024PF00797 10 September 2025

[0099] P2024 , 0728 WO N

[0100] 18

[0101] Figure 1 shows a sectional view of an edge-emitting semiconductor laser according to an exemplary embodiment.

[0102] Figure 2 shows a top view of a lattice structure according to an exemplary embodiment.

[0103] Figures 3 and 4 show cross-sectional views of edge-emitting semiconductor lasers according to comparative examples.

[0104] Identical, similar, or similarly functioning elements are marked with the same reference symbols in the figures. The figures and the relative sizes of the elements depicted within them are not to be considered to scale. Rather, individual elements, particularly layer thicknesses, may be exaggerated for clarity and / or better understanding.

[0105] Figure 1 shows a sectional view of an edge-emitting semiconductor laser 10 according to an exemplary embodiment. The edge-emitting semiconductor laser 10 comprises a first semiconductor layer 1, a second semiconductor layer 3, and an active region 2. The first semiconductor layer 1 can have a first conductivity type. The second semiconductor layer 3 can have a second conductivity type. The active region 2 is arranged between the first semiconductor layer 1 and the second semiconductor layer 3. For example, the active region 2 is configured to generate electromagnetic radiation. The first semiconductor layer 1, the active region 2, and the second semiconductor layer 3 are 2024PF00797 10. September 2025

[0106] P2024 , 0728 WO N

[0107] 19, for example, are arranged consecutively along a stacking direction. The stacking direction can be parallel or at least approximately parallel to a vertical direction z. The vertical direction z is perpendicular to lateral directions x, y.

[0108] The edge-emitting semiconductor laser 10 further comprises a contact layer 7 for electrically contacting the first semiconductor layer 1. The contact layer 7 is arranged on the side of the first semiconductor layer 1 facing away from the active region 2. The contact layer 7 can be directly adjacent to the first semiconductor layer 1. The contact layer 7 can be transparent or translucent. For example, the contact layer 7 is transparent, translucent, and / or transmits the electromagnetic radiation generated by the active region 2. The contact layer 7 has, for example, at least one transparent, electrically conductive oxide (TCO), or consists of one or more TCOs. For example, the contact layer has or consists at least approximately of ITO.

[0109] The edge-emitting semiconductor laser 10 also has a lattice structure 8. The lattice structure 8 can comprise a plurality of structures 12. The structures 12 can be spaced apart from one another. The lattice structure 8 can be located, at least partially, between the first semiconductor layer 1 and the contact layer 7. For example, the lattice structure 8 comprises a metal, a semiconductor material, a dielectric material, and / or an organic material. This can mean, in particular, that the structures 12 of the lattice structure 8 comprise a metal, a 2024PF00797 10. September 2025

[0110] P2024 , 0728 WO N

[0111] - 20 -

[0112] Semiconductor material, a dielectric material and / or an organic material, or consisting of or consisting of .

[0113] The lattice structure 8 can have at least one gap 11, which is arranged, for example, between adjacent structures 12. In particular, the lattice structure 8 comprises a plurality of gaps 11. The contact layer 7 can be arranged in the gaps 11. For example, in the region of the gaps 11, the contact layer 7 borders directly on the first semiconductor layer 1.

[0114] The edge-emitting semiconductor laser 10 further comprises a support 4. The support 4 is, for example, located on the side of the semiconductor layer sequence facing away from the lattice structure 8 and / or the contact layer 7. In other words, the support 4 can be located on the side of the second semiconductor layer 3 facing away from the active region 2. The support 4 can, for example, be a growth substrate. This can mean that the second semiconductor layer 3, the active region 2, and / or the first semiconductor layer 1 were epitaxially grown onto the support 4. However, it is also possible that the support 4 is different from the growth substrate. For example, the support 4 may be GaN, sapphire, Si, GaAs, CuW (copper-wool ram), and / or Mo (molybdenum), or may consist of at least one of these materials.

[0115] The edge-emitting semiconductor laser 10 shown here has an electrical contact 5. The electrical contact 5 is located on the side of the first semiconductor layer 1 facing away from the active region 2. In particular, the electrical contact 5 can be located on the side of the first semiconductor layer 1 2024PF00797 10. September 2025

[0116] P2024 , 0728 WO N

[0117] - 21 - be arranged on the opposite side of the contact layer 7. The electrical contact 5 can be configured for electrical contacting the first semiconductor layer 1.

[0118] That the semiconductor laser 10 is an edge-emitting semiconductor laser 10 can mean that the semiconductor laser 10 emits electromagnetic radiation parallel or perpendicular to the lateral direction x, y. For example, the edge-emitting semiconductor laser 10 includes a facet that extends perpendicular or perpendicular to a principal extension plane of the edge-emitting semiconductor laser 10. The electromagnetic radiation generated by the active region 2 can be coupled out of the semiconductor laser 10 at the facet.

[0119] The edge-emitting semiconductor laser 10, for example, includes a ridge waveguide 9. The ridge waveguide 9 can also be referred to as a laser ridge, ridge structure, or waveguide structure. The ridge waveguide 9 can be a region on the side of the edge-emitting semiconductor laser 10 where the first semiconductor layer 1 is located, and where the first semiconductor layer 1 has a greater thickness than in regions outside the ridge waveguide 9.

[0120] The lattice structure 8 can be arranged, in particular, in the region of the waveguide 9 on the first semiconductor layer 1. It is also possible that the lattice structure 8 is integrated into the waveguide 9.

[0121] The edge-emitting semiconductor laser 10 has an optical field 6. The grating structure 8 can partially overlap with the optical field 6 of the semiconductor laser 10. 2024PF00797 10. September 2025

[0122] P2024 , 0728 WO N

[0123] - 22 -

[0124] In conjunction with Figure 1, a method for fabricating an edge-emitting semiconductor laser 10 is also described. First, the semiconductor layer sequence, comprising the first semiconductor layer 1 of a first conductivity type, the second semiconductor layer 3 of a second conductivity type, and the active region 2, is provided. For example, the second semiconductor layer 3 is epitaxially grown onto a growth substrate, such as the support 4. Subsequently, the active region 2 and the first semiconductor layer 1 are epitaxially grown onto the second semiconductor layer 3 and / or onto the support 4. The lattice structure 8 with the plurality of structures 12 can then be deposited onto the semiconductor layer sequence. For example, the contact layer 7 for electrical contacting the first semiconductor layer 1 is then deposited onto the lattice structure 8.

[0125] For example, a bridge waveguide 9 was formed before the application of the grid structure 8. The grid structure 8 can then be applied to the first semiconductor layer 1, particularly in the region of the bridge waveguide 9.

[0126] After the application of the contact layer 7, for example the electrical contact 5 is applied to the contact layer 7 or created on the contact layer 7.

[0127] Figure 2 shows a top view of a lattice structure 8, for example, of a web waveguide 9 with lattice structure 8 according to an exemplary embodiment. The lattice structure 8 has a lattice period g, in particular a constant lattice period g. For example, see 2024PF00797 10. September 2025

[0128] P2024 , 0728 WO N

[0129] - 23 - Here, g denotes the lattice period, X a wavelength of the semiconductor laser, and n eff is an effective refractive index of a guided light mode. The grating period g can be the first-order grating period. The grating period g corresponds, for example, to a distance between adjacent structures 12 of the grating structure 8 along a principal direction of extension of the web waveguide 9. The principal direction of extension of the web waveguide is perpendicular or at least approximately perpendicular to the stacking direction.

[0130] It is also possible that the following holds true for the lattice period g:

[0131] Here, x can take on integer values. For example, x is greater than or equal to 1. In other words, the lattice period can be an integer multiple of the first-order lattice period. Thus, for example, it is possible that the lattice structure 8 has a lattice period g or integer multiples of g, where .

[0132] Alternatively or additionally, it is possible that the lattice structure 8 has at least one lattice period g. In other words, the lattice structure 8 can have multiple lattice periods g or a combination of lattice periods g.

[0133] The structures 12 each exhibit a

[0134] Main extension direction on . The main extension direction of a structure 12 or structures 12 is perpendicular or at least approximately perpendicular to the 2024PF00797 10 September 2025

[0135] P2024 , 0728 WO N

[0136] - 24 -

[0137] Main direction of extension of the waveguide 9. The structures 12 can be oriented parallel to each other. There is a gap 11 between each adjacent structure 12.

[0138] The spaces 11 can be filled with the material of the contact layer 7, not shown. For example, the spaces 11 are completely filled with the material of the contact layer 7.

[0139] Figure 3 shows a sectional view of an edge-emitting semiconductor laser 10 according to a comparative example. The edge-emitting semiconductor laser 10 shown here has a first semiconductor layer 1, an active region 2, and a second semiconductor layer 3. The second semiconductor layer 3, the active region 2, and the first semiconductor layer 1 are, for example, epitaxially grown on a support 4. The edge-emitting semiconductor laser 10 includes a waveguide 9. An electrical contact 5 is arranged on the side of the first semiconductor layer 1 facing away from the support 4, in particular in the region of the waveguide 9.

[0140] In comparison to the edge-emitting semiconductor laser 10 shown in Figure 1, the edge-emitting semiconductor laser 10 shown in Figure 3 does not include a lattice structure 8 and a contact layer 7. Furthermore, the semiconductor laser 10 is not shaped such that the optical field is guided close to the top surface of the semiconductor laser 10.

[0141] Figure 4 shows a sectional view of an edge-emitting semiconductor laser 10 according to a comparative example. The semiconductor laser shown in Figure 4 is 2024PF00797 10. September 2025

[0142] P2024 , 0728 WO N

[0143] 25

[0144] 10 differs from the one shown in Figure 3

[0145] The semiconductor laser 10 is characterized by a contact layer 7 arranged between the electrical contact 5 and the first semiconductor layer 1. The contact layer 7 extends the optical field 6 further towards the top of the semiconductor laser 10.

[0146] This patent application claims priority from German patent application 10 2024 126 995 . 2 , the disclosure content of which is hereby incorporated by reference.

[0147] The invention is not limited to the description provided by the exemplary embodiments. Rather, the invention encompasses every new feature as well as every combination of features, which in particular includes every combination of features in the patent claims, even if that feature or combination itself is not explicitly specified in the patent claims or exemplary embodiments.

[0148] 2024PF00797 10 . September 2025

[0149] P2024 , 0728 WO N

[0150] 26

[0151] Reference character list

[0152] 1 first semiconductor layer

[0153] 2 active area 3 second semiconductor layer

[0154] 4 carriers

[0155] 5 electrical contacts

[0156] 6 optical field

[0157] 7 Contact layer 8 Lattice structure

[0158] 9 Bridge waveguides

[0159] 10 semiconductor lasers

[0160] 11 space

[0161] 12 Structure g Lattice period x, y lateral direction z vertical direction

Claims

2024PF00797 September 10, 2025 P2024, 0728 WO N - 27 - Patent claims 1. Edge-emitting semiconductor laser (10) , comprising - a first semiconductor layer (1) having a first conductivity type, - a second semiconductor layer (3) which has a second conductivity type, - an active region (2) which is arranged between the first semiconductor layer and the second semiconductor layer and is configured to generate electromagnetic radiation, - a contact layer (7) for electrical contacting the first semiconductor layer (1) , and - a lattice structure (8) with a plurality of structures (12) which are spaced apart from each other, wherein - the contact layer (7) is arranged on the side of the first semiconductor layer (1) facing away from the active area (2), and - the lattice structure (8) is arranged between the first semiconductor layer (1) and the contact layer (7).

2. Edge-emitting semiconductor laser (10) according to the preceding claim, wherein the semiconductor laser (10) is a DFB laser and the grating structure (8) is configured to select a wavelength of a main emission of the semiconductor laser (10).

3. Edge-emitting semiconductor laser (10) according to one of the preceding claims, wherein the contact layer (7) is transparent. 2024PF00797 September 10, 2025 P2024, 0728 WO N - 28 - 4. Edge-emitting semiconductor laser (10) according to one of the preceding claims, wherein the contact layer (7) comprises indium tin oxide (ITO).

5. Edge-emitting semiconductor laser (10) according to one of the preceding claims, wherein the grating structure (8) is configured for refractive index coupling, absorption coupling and / or gain modulation via current path modulation.

6. Edge-emitting semiconductor laser (10) according to one of the preceding claims, wherein the lattice structure (8) comprises a metal.

7. Edge-emitting semiconductor laser (10) according to one of the preceding claims, wherein the lattice structure (8) comprises a semiconductor material.

8. Edge-emitting semiconductor laser (10) according to one of the preceding claims, wherein the lattice structure (8) comprises a dielectric material.

9. Edge-emitting semiconductor laser (10) according to one of the preceding claims, wherein the lattice structure (8) comprises an organic material.

10. Edge-emitting semiconductor laser (10) according to one of the preceding claims, wherein the lattice structure (8) partially overlaps with an optical field (6) of the semiconductor laser (10).

11. Edge-emitting semiconductor laser (10) according to one of the preceding claims, wherein the semiconductor laser (10) has a 2024PF00797 September 10, 2025 P2024, 0728 WO N - 29 - has a bridge waveguide (9), and the grid structure (8) is arranged in the area of ​​the bridge waveguide (9) on the first semiconductor layer (1).

12. Edge-emitting semiconductor laser (10) according to the preceding claim, wherein the grid structure (8) is arranged exclusively in the region of the bridge waveguide (9) on the first semiconductor layer (1).

13. Edge-emitting semiconductor laser (10) according to one of claims 11 and 12, wherein the structures (12) have a principal extension direction which is perpendicular to a principal extension direction of the web waveguide (9).

14. Edge-emitting semiconductor laser (10) according to one of the preceding claims, wherein the spaces (11) between the structures (12) are filled with the material of the contact layer (7).

15. Edge-emitting semiconductor laser (10) according to one of the preceding claims, wherein the lattice structure (8) has a lattice period (g), and g = X / (n e ff*2) applies, where g is the lattice period, X is a wavelength of the semiconductor laser and n e ff corresponds to an effective refractive index of a guided light mode.

16. Edge-emitting semiconductor laser (10) according to one of claims 1 to 14, wherein the lattice structure (8) has a lattice period (g) and the lattice period (g) is an integer multiple of X / (n e ff*2) is, where X is a wavelength of the semiconductor laser and n e ff corresponds to an effective refractive index of a guided light mode. 2024PF00797 September 10, 2025 P2024, 0728 WO N - 30 - 17. Edge-emitting semiconductor laser (10) according to one of claims 15 or 16, wherein the lattice structure (8) has at least two lattice periods (g) or a nesting of at least two lattice periods (g).

18. Method for producing an edge-emitting semiconductor laser (10) , comprising: - Providing a sequence of semiconductor layers comprising a first semiconductor layer (1) of a first conductivity type, a second semiconductor layer (3) of a second conductivity type and an active region (2) , wherein the active region (2) is arranged between the first semiconductor layer (1) and the second semiconductor layer (3) and is configured to generate electromagnetic radiation, - Deposition of a lattice structure (8) with a plurality of structures (12) which are spaced apart from each other, onto the semiconductor layer sequence, and - Application of a contact layer (7) for electrical contacting the first semiconductor layer (1) onto the lattice structure (8) .

19. Method according to claim 18, wherein a lattice structure (8) is formed before the application of the lattice structure (8), and the lattice structure (8) is applied to the first semiconductor layer (1) in the area of ​​the lattice structure (9).

20. Method according to one of claims 18 to 19, wherein a metallization is applied to the contact layer (7) to form an electrical contact (5).

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