Semiconductor laser and control method thereof

Abstract

The invention relates to the technical field of lasers, in particular to a semiconductor laser and a control method thereof.The semiconductor laser comprises an epitaxial structure, the top surface of the epitaxial structure is provided with a waveguide structure, the waveguide structure comprises a main waveguide and N coupling waveguides, and the main waveguide and the coupling waveguides are arranged at intervals; wherein the main waveguide supports N transverse modes, the N coupling waveguides are in one-to-one correspondence with the N transverse modes, and the propagation constant of the base transverse mode of each coupling waveguide is matched with the propagation constant of the corresponding transverse mode of the main waveguide; current is injected into the main waveguide, at least one coupling waveguide is selected from the N coupling waveguides to inject current, the remaining coupling waveguides are set to be in a suspended state, and the coupling waveguide for current injection is selected from the N coupling waveguides, so that specific transverse mode selective output is achieved. According to the invention, transverse mode switching of the semiconductor laser is at least facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of lasers, and in particular relates to a semiconductor laser and a control method thereof. Background Art

[0002] Semiconductor lasers play an irreplaceable and important role in key fields such as autonomous driving, laser displays, and optical communications. Currently, mature edge-emitting semiconductor lasers mainly rely on ridge waveguide structures to achieve transverse mode confinement.

[0003] However, the existing structural design and mode control methods cannot achieve mode switching, which to some extent limits its application scope. Summary of the Invention

[0004] In view of this, the present invention aims to provide a semiconductor laser and a control method thereof, which at least facilitates the semiconductor laser to achieve transverse mode switching.

[0005] To achieve the above object, the technical solution created by the present invention is implemented as follows: The present invention provides, on one hand, a semiconductor laser, comprising: an epitaxial structure, wherein the top surface of the epitaxial structure has a waveguide structure, and the waveguide structure includes a main waveguide and N coupled waveguides, and the main waveguide and the coupled waveguides are arranged at intervals; wherein the main waveguide supports N transverse modes, the N coupled waveguides correspond one-to-one to the N transverse modes, the propagation constant of the fundamental transverse mode of each coupled waveguide matches the propagation constant of the corresponding transverse mode of the main waveguide, and N is an integer greater than 1; the main waveguide injects current, at least one coupled waveguide is selected from the N coupled waveguides for current injection, and the remaining coupled waveguides are set to a suspended state, the fundamental transverse mode of the coupled waveguide in the suspended state is coupled with the corresponding transverse mode of the main waveguide, so that the semiconductor laser outputs laser light in an uncoupled transverse mode, and selective output of a specific transverse mode is achieved by selecting the coupled waveguide for current injection from the N coupled waveguides.

[0006] Furthermore, the main waveguide extends along a first direction, and the N coupling waveguides are distributed on two opposite sides of the main waveguide in a second direction.

[0007] Furthermore, one side of the main waveguide has a plurality of coupled waveguides, and the plurality of coupled waveguides located on one side of the main waveguide are arranged in sequence along the first direction.

[0008] Furthermore, for the multiple coupling waveguides located on the same side of the main waveguide, along the second direction, the spacing between each coupling waveguide and the main waveguide is different, and / or the size of each coupling waveguide in the second direction is different.

[0009] Furthermore, a plurality of coupling waveguides located on one side of the main waveguide are arranged at intervals along the first direction, and the orthographic projections of all coupling waveguides on the top surface of the epitaxial structure are circular, and the main waveguide is a straight waveguide extending along the first direction.

[0010] Furthermore, multiple coupling waveguides located on one side of the main waveguide are connected in sequence along the first direction, and the orthographic projections of all coupling waveguides on the top surface of the epitaxial structure are rectangular, and the main waveguide is a straight waveguide extending along the first direction.

[0011] Furthermore, the top electrodes of the multiple coupled waveguides connected in sequence are independent of each other.

[0012] Furthermore, current is injected into the main waveguide, and one coupling waveguide is selected from the N coupling waveguides to inject current and the remaining coupling waveguides are set to a suspended state. The fundamental transverse mode of the coupling waveguide in the suspended state is coupled with the corresponding transverse mode of the main waveguide, so that the semiconductor laser outputs a single transverse mode laser. By selecting the coupling waveguide for current injection from the N coupling waveguides, selective output of a specific single transverse mode is achieved.

[0013] Furthermore, N is 4, the four coupling waveguides are the first coupling waveguide, the second coupling waveguide, the third coupling waveguide and the fourth coupling waveguide, and the four transverse modes supported by the main waveguide are the fundamental transverse mode, the first-order transverse mode, the second-order transverse mode and the third-order transverse mode, wherein the propagation constant of the fundamental transverse mode of the first coupling waveguide matches the propagation constant of the fundamental transverse mode of the main waveguide, the propagation constant of the fundamental transverse mode of the second coupling waveguide matches the propagation constant of the first-order transverse mode of the main waveguide, the propagation constant of the fundamental transverse mode of the third coupling waveguide matches the propagation constant of the second-order transverse mode of the main waveguide, and the propagation constant of the fundamental transverse mode of the fourth coupling waveguide matches the propagation constant of the third-order transverse mode of the main waveguide. The first coupling waveguide, the second coupling waveguide and the third coupling waveguide are located on the first side of the main waveguide, and the fourth coupling waveguide is located on the second side of the coupling waveguide.

[0014] Another aspect of the present invention provides a control method for a semiconductor laser, comprising: providing any of the semiconductor lasers described above, the semiconductor laser comprising an epitaxial structure, the top surface of the epitaxial structure comprising a waveguide structure, the waveguide structure comprising a main waveguide and N coupled waveguides, wherein the main waveguide supports N transverse modes, the N coupled waveguides correspond one-to-one to the N transverse modes, the fundamental transverse mode propagation constant of each coupled waveguide matches the transverse mode propagation constant of the corresponding main waveguide, and N is an integer greater than 1; injecting current into the main waveguide, selecting at least one coupled waveguide among the N coupled waveguides to inject current and leaving the remaining coupled waveguides in a suspended state, the fundamental transverse mode of the coupled waveguides in the suspended state coupled with the transverse mode corresponding to the main waveguide, so that the semiconductor laser outputs laser light in an uncoupled transverse mode, and selective output of a specific transverse mode is achieved by selecting the coupled waveguide to which the current is injected among the N coupled waveguides.

[0015] Compared with the prior art, the invention can achieve the following beneficial effects: in the semiconductor laser provided by the present invention, the waveguide structure includes a main waveguide and a coupling waveguide, and the fundamental transverse mode of the coupling waveguide matches the propagation constant of the transverse mode of the corresponding main waveguide, and the main waveguide always injects current. When a coupling waveguide injects current, the mode effective refractive index of the coupling waveguide changes and cannot match the propagation constant of the transverse mode of the corresponding main waveguide, while the coupling waveguide without current injection matches the propagation constant of the corresponding transverse mode of the main waveguide, so that the corresponding transverse mode of the main waveguide is coupled. In this way, by selectively injecting current into the coupling waveguide, the selection of a specific transverse mode of the main waveguide and the switching of the transverse mode can be achieved; in addition, the preparation method of the semiconductor laser is simple, low-cost, and conducive to large-scale production; and when the main waveguide is relatively wide, specific single transverse mode lasing and switching of multiple single transverse modes can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings: Figure 1 A schematic structural diagram of a semiconductor laser according to an embodiment of the present invention; Figure 2 A top view of a semiconductor laser according to an embodiment of the present invention is created; Figure 3 A top view of a semiconductor laser according to another embodiment of the present invention; Figure 4 A top view of a semiconductor laser according to another embodiment of the present invention is provided. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0018] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0019] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0020] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0021] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0022] refer to Figures 1 to 4 The present invention provides a semiconductor laser, comprising: an epitaxial structure, wherein the top surface of the epitaxial structure has a waveguide structure, and the waveguide structure includes a main waveguide 111 and N coupling waveguides 110, and the main waveguide 111 and the coupling waveguides 110 are arranged at intervals; wherein the main waveguide 111 supports N transverse modes, and the N coupling waveguides 110 correspond one-to-one to the N transverse modes, and the propagation constant of the fundamental transverse mode of each coupling waveguide 110 matches the propagation constant of the corresponding transverse mode of the main waveguide 111, and N is an integer greater than 1; the main waveguide 111 is injected with current, and at least one coupling waveguide 110 is selected from the N coupling waveguides 110 to be injected with current and the remaining coupling waveguides 110 are set to a suspended state, and the fundamental transverse mode of the suspended coupling waveguide 110 is coupled with the corresponding transverse mode of the main waveguide 111, so that the semiconductor laser outputs laser light in an uncoupled transverse mode, and selective output of a specific transverse mode is achieved by selecting the coupling waveguide 110 to be injected with current among the N coupling waveguides 110.

[0023] It should be noted that matching the propagation constant of the fundamental transverse mode of the coupled waveguide with the propagation constant of the corresponding transverse mode of the main waveguide means that the difference between the propagation constants thereof is not greater than 0.1.

[0024] In some embodiments, the epitaxial structure includes an N-type electrode layer 101, a substrate layer 102, an N-type cap layer 103, an N-type waveguide layer 104, an active layer 105, a P-type waveguide layer 106, a P-type cap layer 107 and a P-type electrode layer 109 arranged in sequence from bottom to top. The waveguide structure is composed of a portion of the P-type cap layer 107, and the P-type electrode layer 109 is located on the top surface of the waveguide structure.

[0025] The material composition, thickness, and doping concentration of each layer in the epitaxial structure of the semiconductor laser provided by the present invention can be similar to the designs of mature, widely used epitaxial structures of edge-emitting semiconductor lasers. For example, the corresponding material system can be selected based on the emission wavelength. For example, if the emission wavelength is within the range of 600nm to 1200nm, a gallium arsenide material system can be used; if the emission wavelength is within the range of 1300nm to 1700nm, an indium phosphide material system can be used.

[0026] The specific structure of the semiconductor laser provided by the present invention is described in detail below using a gallium arsenide material system as an example.

[0027] In some embodiments, the epitaxial structure includes: a substrate layer 102 made of N-type GaAs; an N-type cap layer 103 made of AlGaAs, wherein the Al content of the N-type cap layer 103 may be in the range of 0.2 to 0.6, the thickness of the N-type cap layer 103 may be in the range of 0.1 μm to 3 μm, and the dopant of the N-type cap layer 103 may be Si, and the doping concentration of Si may be 1E17 / cm 3 ~1E19 / cm 3 The N-type waveguide layer 104 is made of AlGaAs, the Al content in the N-type waveguide layer 104 may be in the range of 0.05 to 0.7, the thickness of the N-type waveguide layer 104 may be in the range of 0.1 μm to 10 μm, the dopant of the N-type waveguide layer 104 may be Si, and the doping concentration of Si may be 1E16 / cm 3 ~8E18 / cm 3The active layer 105 may be a barrier layer / quantum well layer / barrier layer structure, the barrier layer may be made of AlGaAs, the quantum well layer may be made of InGaAs, the In content of the quantum well layer may be in the range of 0-0.5, the Al content of the barrier layer may be in the range of 0-0.5, the thickness of the barrier layer may be in the range of 1nm-200nm, and the thickness of the quantum well layer may be in the range of 1nm-20nm; the emission wavelength of the semiconductor laser may be in the range of 700nm-1200nm; the P-type waveguide layer 106 may be made of AlGaAs, the Al content of the P-type waveguide layer 106 may be in the range of 0.05-0.7, the thickness of the P-type waveguide layer 106 may be in the range of 0.1μm-10μm, the dopant of the P-type waveguide layer 106 may be C, and the doping concentration of C may be 1E16 / cm 3 ~8E18 / cm 3 The material of the P-type cap layer 107 is AlGaAs, the Al content in the P-type cap layer 107 is in the range of 0.4 to 0.6, the thickness of the P-type cap layer 107 can be in the range of 0.1 μm to 3 μm, the dopant of the P-type cap layer 107 can be C, and the doping concentration of C can be 1E17 / cm 3 ~1E19 / cm 3 the thickness of the P-type electrode layer 109 may be between 200 nm and 500 nm, and the material of the P-type electrode layer 109 may include at least one of titanium, platinum, gold, nickel, and germanium; the thickness of the N-type electrode layer 101 is the same as the thickness of the P-type electrode layer 109, and the material of the N-type electrode layer 101 is the same as the material of the P-type electrode layer 109.

[0028] In some embodiments, the semiconductor laser further includes an insulating layer 108, a P-type electrode layer 109 penetrates the insulating layer 108 and contacts the corresponding main waveguide 111 or the coupling waveguide 110, the material of the insulating layer 108 may include at least one of SiO2 and Si3N4, and the thickness of the insulating layer 108 may be in the range of 50nm to 100nm.

[0029] It should be noted that the width of the main waveguide 111 satisfies the requirement that the main waveguide 111 supports N transverse modes. The semiconductor laser provided by the present invention is described in detail below by taking N as 4 as an example.

[0030] In some examples, N is 4, and the width of the main waveguide 111 satisfies that the main waveguide 111 supports four transverse modes, namely a fundamental transverse mode, a first-order transverse mode, a second-order transverse mode, and a third-order transverse mode. The width and height of the coupling waveguide 110 satisfy a condition that the propagation constant of the fundamental transverse mode of the coupling waveguide 110 matches the propagation constant of the corresponding transverse mode of the main waveguide 111.

[0031] In some embodiments, the main waveguide 111 extends along a first direction X, and the N coupling waveguides 110 are distributed on opposite sides of the main waveguide 111 in a second direction Y.

[0032] In some embodiments, a main waveguide 111 has multiple coupling waveguides 110 on one side, and the multiple coupling waveguides 110 on one side of the main waveguide 111 are arranged sequentially along the first direction X. This helps avoid the multiple coupling waveguides 110 on one side of the main waveguide 111 from occupying too much space, thereby improving the integration level.

[0033] In some embodiments, for the multiple coupling waveguides 110 located on the same side of the main waveguide 111, the spacing between each coupling waveguide 110 and the main waveguide 111 along the second direction Y is different, and / or the size of each coupling waveguide 110 in the second direction Y is different.

[0034] In some embodiments, reference Figure 3 , multiple coupling waveguides 110 located on one side of the main waveguide 111 are arranged at intervals along the first direction X, and the orthographic projections of all the coupling waveguides 110 on the top surface of the epitaxial structure are circular, and the main waveguide 111 is a straight waveguide extending along the first direction X. For example, N is 4, and the four coupling waveguides 110 are respectively the first coupling waveguide 121, the second coupling waveguide 122, the third coupling waveguide 123 and the fourth coupling waveguide 124. The first coupling waveguide 121, the second coupling waveguide 122, the third coupling waveguide 123 and the fourth coupling waveguide 124 all adopt a micro-ring structure. The radius, height and distance between the first coupling waveguide 121 and the main waveguide 111 meet the conditions that the propagation constant of the fundamental transverse mode of the first coupling waveguide 121 matches the propagation constant of the fundamental transverse mode of the main waveguide 111. The radius, height and distance between the second coupling waveguide 122 and the main waveguide 111 meet the conditions that the propagation constant of the fundamental transverse mode of the first coupling waveguide 121 matches the propagation constant of the fundamental transverse mode of the main waveguide 111. The distance between the coupling waveguides 110 and the main waveguide 111 satisfies the condition that the propagation constant of the fundamental transverse mode of the second coupling waveguide 122 matches the propagation constant of the first-order transverse mode of the main waveguide 111. The radius, height, and distance between the third coupling waveguide 123 and the main waveguide 111 satisfy the condition that the propagation constant of the fundamental transverse mode of the third coupling waveguide 123 matches the propagation constant of the second-order transverse mode of the main waveguide 111. The radius, height, and distance between the fourth coupling waveguide 124 and the main waveguide 111 satisfy the condition that the propagation constant of the fundamental transverse mode of the fourth coupling waveguide 124 matches the propagation constant of the third-order transverse mode of the main waveguide 111. The distance between the coupling waveguide 110 and the main waveguide 111 and the height setting of the waveguide structure can be obtained through numerical simulation to ensure that the propagation constant of the corresponding transverse mode of the main waveguide 111 matches the propagation constant of the fundamental transverse mode of the corresponding coupling waveguide 110.

[0035] In some embodiments, multiple coupling waveguides 110 located on one side of the main waveguide 111 are connected in sequence along the first direction X, and the orthographic projections of all coupling waveguides 110 on the top surface of the epitaxial structure are rectangular, and the main waveguide 111 is a straight waveguide extending along the first direction X.

[0036] In some embodiments, the top electrodes of the multiple coupled waveguides 110 connected in sequence are independent of each other, and the top electrodes are P-type electrodes.

[0037] In some embodiments, current is injected into the main waveguide 111, and one coupling waveguide 110 is selected from the N coupling waveguides 110 to inject current, and the remaining coupling waveguides 110 are set to a suspended state. The fundamental transverse mode of the coupling waveguide 110 in the suspended state is coupled with the corresponding transverse mode of the main waveguide 111, so that the semiconductor laser outputs a single transverse mode laser. By selecting the coupling waveguide 110 for current injection from the N coupling waveguides 110, selective output of a specific single transverse mode is achieved. In some usage scenarios, a wider main waveguide is required, but a wider main waveguide often leads to simultaneous lasing of multiple transverse modes, and multiple transverse modes may oscillate together, causing multiple modes to overlap and the beam quality to be greatly reduced. Therefore, in some usage scenarios, a semiconductor laser may be required to output a single transverse mode laser. It should be noted that the light field of the fundamental transverse mode appears as a single light spot, the light field of the first-order transverse mode appears as two symmetrical light spots, and the light field of the second-order transverse mode appears as three light spots, and so on. For a semiconductor laser operating in a specific single transverse mode, the light spot it emits is a regular single light spot or multiple Gaussian light spots. This unique light spot characteristic is of great value in studying the light field characteristics of the device and emerging applications. Therefore, a coupling waveguide 110 can be selected from the N coupling waveguides 110 for current injection to achieve selective output of a specific single transverse mode. By switching the current-injected coupling waveguide 110, switching of multiple single transverse modes can be achieved.

[0038] In some embodiments, reference Figure 2, N is 4, the four coupling waveguides 110 are respectively the first coupling waveguide 121, the second coupling waveguide 122, the third coupling waveguide 123 and the fourth coupling waveguide 124, the four transverse modes supported by the main waveguide 111 are respectively the fundamental transverse mode, the first-order transverse mode, the second-order transverse mode and the third-order transverse mode, wherein the propagation constant of the fundamental transverse mode of the first coupling waveguide 121 matches the propagation constant of the fundamental transverse mode of the main waveguide 111, and the propagation constant of the fundamental transverse mode of the second coupling waveguide 122 matches the propagation constant of the fundamental transverse mode of the main waveguide 1 11, the propagation constant of the fundamental transverse mode of the third coupling waveguide 123 matches the propagation constant of the second-order transverse mode of the main waveguide 111, and the propagation constant of the fundamental transverse mode of the fourth coupling waveguide 124 matches the propagation constant of the third-order transverse mode of the main waveguide 111. The first coupling waveguide 121, the second coupling waveguide 122 and the third coupling waveguide 123 are located on a first side of the main waveguide 111, and the fourth coupling waveguide 124 is located on a second side of the coupling waveguide 110.

[0039] Specifically, the distance between the main waveguide 111 and the first coupling waveguide 121 may be d1, the distance between the main waveguide 111 and the second coupling waveguide 122 may be d2, the distance between the main waveguide 111 and the third coupling waveguide 123 may be d3, and the distance between the main waveguide 111 and the fourth coupling waveguide 124 may be d4. In some examples, referring to Figure 4 , d1, d2, d3 and d4 may all be the same; in other examples, d1, d2, d3 and d4 may all be different, or some of d1, d2, d3 and d4 may be the same and the other may be different.

[0040] In some embodiments, the main waveguide 111 is applied with a forward voltage from the P-type electrode as the laser output end. If the main waveguide 111 is required to output a fundamental transverse mode, the first coupling waveguide 121 is applied with a forward voltage from the P-type electrode, and the second coupling waveguide 122, the third coupling waveguide 123 and the fourth coupling waveguide 124 are all grounded from the P-type electrode or suspended. If the main waveguide 111 is required to output a first-order transverse mode, the second coupling waveguide 122 is applied with a forward voltage from the P-type electrode, and the first coupling waveguide 121, the third coupling waveguide 123 and the fourth coupling waveguide 124 are all grounded from the P-type electrode. 24 are all grounded from the P-type electrode or suspended; if the main waveguide 111 is required to output the second-order transverse mode, the third coupling waveguide 123 applies a forward voltage from the P-type electrode, and the first coupling waveguide 121, the second coupling waveguide 122 and the fourth coupling waveguide 124 are all grounded from the P-type electrode or suspended; if the main waveguide 111 is required to output the third-order transverse mode, the fourth coupling waveguide 124 applies a forward voltage from the P-type electrode, and the first coupling waveguide 121, the second coupling waveguide 122 and the third coupling waveguide 123 are all grounded from the P-type electrode or suspended.

[0041] In some embodiments, the manufacturing method of the semiconductor laser includes: step 1, designing and etching a first photolithography layout for a waveguide structure and a second photolithography layout for a P-type electrode; step 2, on a substrate layer 102, sequentially preparing an N-type cap layer 103, an N-type waveguide layer 104, an active layer 105, a P-type waveguide layer 106, and a P-type cap layer 107 by epitaxial growth to obtain an initial epitaxial structure; step 3, performing a patterning process on the surface of the initial epitaxial structure using the first photolithography layout to prepare a waveguide structure; step 4, forming a substrate containing a waveguide An insulating layer 108 is grown on the top surface of the structure using PECVD equipment; in step five, the insulating layer 108 is etched using a second photolithography pattern to form a current injection window; in step six, a P-type electrode layer is grown in the current injection window using a metal film evaporation device; in step seven, the substrate layer 102 is thinned, polished, and cleaned, and an N-type electrode layer 101 is sputtered on the bottom surface of the substrate layer 102, and an annealing process is performed to form an ohmic contact; in step eight, the bar strips are cleaved, an anti-reflection film is coated on the backlight surface, and the bar strips are cleaved into chips.

[0042] Another aspect of the present invention provides a control method for a semiconductor laser, comprising: providing any of the semiconductor lasers described above, the semiconductor laser comprising an epitaxial structure, the top surface of the epitaxial structure comprising a waveguide structure, the waveguide structure comprising a main waveguide 111 and N coupling waveguides 110, wherein the main waveguide 111 supports N transverse modes, the N coupling waveguides 110 correspond one-to-one to the N transverse modes, the fundamental transverse mode propagation constant of each coupling waveguide 110 matches the propagation constant of the corresponding transverse mode of the main waveguide 111, and N is an integer greater than 1; injecting current into the main waveguide 111, selecting at least one coupling waveguide 110 among the N coupling waveguides 110 to inject current and leaving the remaining coupling waveguides 110 in a suspended state, the fundamental transverse mode of the suspended coupling waveguide 110 being coupled to the corresponding transverse mode of the main waveguide 111, so that the semiconductor laser outputs laser light in an uncoupled transverse mode, and selective output of a specific transverse mode is achieved by selecting the coupling waveguide 110 to which the current is injected among the N coupling waveguides 110.

[0043] In some embodiments, current is injected into the main waveguide 111, and one coupling waveguide 110 is selected from the N coupling waveguides 110 to inject current, and the remaining coupling waveguides 110 are set to a suspended state. The fundamental transverse mode of the coupling waveguide 110 in the suspended state is coupled with the corresponding transverse mode of the main waveguide 111, so that the semiconductor laser outputs a single transverse mode laser. By selecting the coupling waveguide 110 for current injection from the N coupling waveguides 110, selective output of a specific single transverse mode is achieved.

[0044] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present disclosure can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in the present disclosure can be achieved. This is not limited herein.

[0045] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A semiconductor laser, characterized in that include: An epitaxial structure, wherein a top surface of the epitaxial structure has a waveguide structure, and the waveguide structure includes a main waveguide and N coupled waveguides, and the main waveguide and the coupled waveguides are arranged at intervals; The main waveguide supports N transverse modes, the N coupled waveguides correspond one-to-one to the N transverse modes, the propagation constant of the fundamental transverse mode of each coupled waveguide matches the propagation constant of the corresponding transverse mode of the main waveguide, and N is an integer greater than 1; The main waveguide injects current, at least one coupling waveguide is selected from the N coupling waveguides to inject current and the remaining coupling waveguides are set to a suspended state, the fundamental transverse mode of the coupling waveguide in the suspended state is coupled with the corresponding transverse mode of the main waveguide, so that the semiconductor laser outputs laser light in an uncoupled transverse mode, and by selecting the coupling waveguide for current injection from the N coupling waveguides, selective output of a specific transverse mode is achieved.

2. The semiconductor laser according to claim 1, wherein The main waveguide extends along a first direction, and the N coupling waveguides are distributed on opposite sides of the main waveguide in a second direction.

3. The semiconductor laser according to claim 2, wherein One side of the main waveguide has a plurality of coupled waveguides, and the plurality of coupled waveguides located on one side of the main waveguide are arranged in sequence along a first direction.

4. The semiconductor laser according to claim 3, wherein For the multiple coupling waveguides located on the same side of the main waveguide, along the second direction, the spacing between each coupling waveguide and the main waveguide is different, and / or the size of each coupling waveguide in the second direction is different.

5. The semiconductor laser according to claim 3, wherein A plurality of coupling waveguides located on one side of the main waveguide are arranged at intervals along the first direction, and the orthographic projections of all coupling waveguides on the top surface of the epitaxial structure are circular. The main waveguide is a straight waveguide extending along the first direction.

6. The semiconductor laser according to claim 3, wherein A plurality of coupling waveguides located on one side of the main waveguide are connected in sequence along a first direction, and the orthographic projections of all coupling waveguides on the top surface of the epitaxial structure are rectangular. The main waveguide is a straight waveguide extending along the first direction.

7. The semiconductor laser according to claim 6, characterized in that The top electrodes of the multiple coupled waveguides connected in sequence are independent of each other.

8. The semiconductor laser according to claim 1, wherein The main waveguide injects current, and a coupling waveguide is selected from the N coupling waveguides to inject current and the remaining coupling waveguides are set to a suspended state. The fundamental transverse mode of the coupling waveguide in the suspended state is coupled with the corresponding transverse mode of the main waveguide, so that the semiconductor laser outputs a single transverse mode laser. By selecting the coupling waveguide for current injection from the N coupling waveguides, the selective output of a specific single transverse mode is achieved.

9. The semiconductor laser according to claim 1, wherein N is 4, the four coupling waveguides are respectively a first coupling waveguide, a second coupling waveguide, a third coupling waveguide and a fourth coupling waveguide, the four transverse modes supported by the main waveguide are respectively a fundamental transverse mode, a first-order transverse mode, a second-order transverse mode and a third-order transverse mode, wherein the propagation constant of the fundamental transverse mode of the first coupling waveguide matches the propagation constant of the fundamental transverse mode of the main waveguide, the propagation constant of the fundamental transverse mode of the second coupling waveguide matches the propagation constant of the first-order transverse mode of the main waveguide, the propagation constant of the fundamental transverse mode of the third coupling waveguide matches the propagation constant of the second-order transverse mode of the main waveguide, and the propagation constant of the fundamental transverse mode of the fourth coupling waveguide matches the propagation constant of the third-order transverse mode of the main waveguide, the first coupling waveguide, the second coupling waveguide and the third coupling waveguide are located on a first side of the main waveguide, and the fourth coupling waveguide is located on a second side of the coupling waveguide.

10. A method for controlling a semiconductor laser, characterized in that: include: A semiconductor laser according to any one of claims 1 to 9 is provided, the semiconductor laser comprising an epitaxial structure, the top surface of the epitaxial structure having a waveguide structure, the waveguide structure comprising a main waveguide and N coupled waveguides, wherein the main waveguide supports N transverse modes, the N coupled waveguides correspond one-to-one to the N transverse modes, a fundamental transverse mode propagation constant of each coupled waveguide matches a corresponding transverse mode propagation constant of the main waveguide, and N is an integer greater than 1; Current is injected into the main waveguide, and at least one coupling waveguide is selected from the N coupling waveguides to inject current and the remaining coupling waveguides are suspended. The fundamental transverse mode of the coupling waveguide in the suspended state is coupled with the corresponding transverse mode of the main waveguide, so that the semiconductor laser outputs laser light in an uncoupled transverse mode. By selecting the coupling waveguide for current injection from the N coupling waveguides, selective output of a specific transverse mode is achieved.

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