A Y-shaped high-power single-mode semiconductor laser and a preparation method thereof

Abstract

The present invention relates to a Y-shaped high-power single-mode semiconductor laser and a preparation method thereof, which includes a substrate, a transition layer, an N confinement layer, an N waveguide layer, a quantum well active layer, a P waveguide layer, and a P confinement layer that are sequentially connected together from bottom to top. A convex shoulder is provided on the surface of the P confinement layer, and a ridge waveguide is provided between the shoulders. The ridge waveguide gradually divides into two identical branches backward to form a Y-shaped structure, which can simultaneously achieve gain and beam combination at the ridge waveguide junction, enhancing the overall gain efficiency of the device and increasing the laser power. At the same time, there is a deep groove structure between the two symmetric arms of the Y-shaped waveguide to isolate the optical interference between the two symmetric branch waveguides. The width of the ridge waveguide near the light-emitting surface of the laser is widened and presents a conical shape. The conical structure is used to expand the optical field of the laser, reduce the energy density of the light-emitting surface, and reduce the probability of damage. Moreover, this structure will further enhance the gain pressure of the fundamental mode, realizing the efficient and stable output of single-mode light by the laser under high-power conditions.

Description

Technical Field

[0001] The present invention relates to a Y-shaped high-power single-mode semiconductor laser and a preparation method thereof, belonging to the technical field of semiconductor lasers. Background Art

[0002] Semiconductor variable-emission lasers, especially semiconductor lasers with fundamental transverse mode lasing, are widely used in fields such as laser indication, laser processing, and optical communication due to their advantages of simple processing technology, high beam quality, concentrated energy, high conversion efficiency, and easy coupling. Due to the material physical properties of semiconductor lasers themselves, the refractive index of the material decreases at high temperatures, causing the optical field confinement factor of semiconductor lasers to decrease. In application scenarios requiring high output power, it is necessary to increase the injection current, and the excessive gain in the laser causes the fundamental mode and high-order modes to oscillate simultaneously, resulting in deterioration of the beam quality. Therefore, fundamental-mode high-power semiconductor lasers have become the main direction of research and development of existing semiconductor lasers.

[0003] Currently, the problem of improving the beam quality faced by high-power edge-emitting lasers is mainly solved by means of device wide-ridge waveguide structure design, secondary epitaxial growth of materials, integration of additional confinement materials or suppression filtering structures in the device, etc. The ridge waveguide of the edge-emitting laser is formed by etching, and it is not easy to set a mode filtering structure or material inside or beside the waveguide structure. Currently, most solutions are to adjust the optical mode distribution of the laser by changing the semiconductor material parameters on the ridge waveguide or the shape and position of the metal electrode, changing the refractive index distribution conditions of the laser cross-section. Since metal materials generally have light absorption, a leaky waveguide can also be set to increase the loss difference between modes, and reduce the high-order modes during laser resonance by suppressing the oscillation threshold, and increase the fundamental mode purity to achieve high-quality fundamental mode Gaussian spot output. In addition, the filtering layer material or microstructure set inside the laser material can also effectively achieve mode filtering, but it greatly improves the requirements for the device processing environment and the process complexity, and is not applicable in industrial production pursuing efficiency.

[0004] Chinese patent document CN109491012A discloses a tunable optical control terahertz beam splitter based on a photonic crystal. Part of the dielectric columns are removed horizontally in the middle of the planar photonic crystal to form an input waveguide, and two waveguide arms and the input waveguide form a Y shape; the silicon dielectric columns on both sides of one of the waveguide arms close to the middle node of the Y shape are replaced with optically controlled point defect dielectric columns. This beam splitter is a passive optical device beam splitter, and the overall device forms a waveguide based on manufacturing defects on the photonic crystal. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a Y-shaped high-power single-mode semiconductor laser, in which a conventional ridge waveguide is gradually divided into two identical branch ridge waveguides after guiding, and the overall structure is Y-shaped. The symmetric branches on the rear side of the Y-shaped waveguide are called the symmetric arms of the Y-shaped waveguide. The light in the Y-shaped structure can achieve gain oscillation. The length of the optical oscillation loop is significantly longer than that of the conventional ridge waveguide semiconductor laser, and simultaneous gain can be achieved. Beam combination is performed at the ridge waveguide junction to enhance the overall gain efficiency of the device and improve the laser power.

[0006] The present invention also provides a preparation method for the above-mentioned Y-shaped high-power single-mode semiconductor laser.

[0007] The technical solution of the present invention is as follows:

[0008] A Y-shaped high-power single-mode semiconductor laser includes a substrate, a transition layer, an N confinement layer, an N waveguide layer, a quantum well active layer, a P waveguide layer, and a P confinement layer that are sequentially connected together from bottom to top. The surface of the P confinement layer is symmetrically provided with raised shoulders, and a ridge waveguide is provided between the shoulders. The ridge waveguide is gradually divided into two branch ridge waveguides from the light output side to the other side, and the overall structure is Y-shaped. The symmetric branches on the other side of the ridge waveguide are the symmetric arms of the Y-shaped waveguide, which can achieve gain simultaneously. Beam combination is performed at the ridge waveguide junction to enhance the overall gain efficiency of the device and improve the laser power. At the same time, a deep groove is provided between the two Y-shaped waveguide symmetric arms to isolate the optical interference between the two symmetric branch waveguides. The width of the ridge waveguide on the light output side of the laser is widened and tapered. This tapered structure is used to expand the optical field of the laser, reduce the energy density of the light output surface, and reduce the probability of damage to the laser cavity surface. A groove is formed between the shoulder and the ridge waveguide, and insulating layers are provided in the groove and on the upper side of the shoulder. An ohmic contact layer is provided on the top of the ridge waveguide, and a P-side metal layer is provided above the insulating layer and the ohmic contact layer.

[0009] Preferably, the cross-section of the ridge waveguide is rectangular or trapezoidal, and the ridge waveguide and the shoulders are integrally formed from the P confinement layer.

[0010] Preferably, the width of the ridge waveguide is 2 μm - 5 μm; the height of the ridge waveguide is the same as the depth of the groove, which is 0.1 μm - 5 μm.

[0011] Preferably, the quantum well active layer is a layered structure formed by sequentially stacking GaInP, AlGaInP, and GaInP, and the thickness of the quantum well active layer is 1 nm - 40 nm.

[0012] Preferably, the insulating layer covers the top and side of the shoulder, and the insulating layer on the shoulder is integrally in a shape like the Chinese character "ji".

[0013] Preferably, the length of the deep groove is 1 / 3 of the length of the laser, the width is 10 μm, and the depth of the deep groove penetrates through the P confinement layer, the P waveguide layer, the quantum well active layer, the N waveguide layer, the N confinement layer, and reaches the substrate.

[0014] Preferably, the tapered ridge waveguide on the laser output surface side is widened to 30 um, and the length of the tapered region is 15 um.

[0015] Preferably, the Y-type high-power single-mode semiconductor laser includes one of the following solutions:

[0016] Ⅰ. The P-side metal layer is at least two of Ti, Pt, Au, Ge, Ni, Cr, Sn;

[0017] Ⅱ. The substrate material is at least one of GaAs, InP, Si;

[0018] Ⅲ. The N confinement layer material is at least one of GaAs, GaInP, AlInP, AlGaInP, AlGaAs, AlGaAsP, InGaAsP;

[0019] Ⅳ. The N waveguide layer material is at least one of GaAs, GaInP, AlInP, AlGaInP, AlGaAs, AlGaAsP, InGaAsP;

[0020] Ⅴ. The P waveguide layer material is at least one of GaAs, GaInP, AlInP, AlGaInP, AlGaAs, AlGaAsP, InGaAsP;

[0021] Ⅵ. The P confinement layer material is at least one of GaAs, GaInP, AlInP, AlGaInP, AlGaAs, AlGaAsP, InGaAsP;

[0022] Ⅶ. The insulating layer material is at least one of SiO2, Si3N4, AlN;

[0023] Ⅷ. The ohmic contact layer material is a C highly doped GaAs material, and the C doping concentration is 1e18.

[0024] Preferably, the Y-type high-power single-mode semiconductor laser includes one of the following solutions:

[0025] Ⅰ. The thickness of the P-side metal layer is 0.2 um - 2 um;

[0026] Ⅱ. The thickness of the N confinement layer is 1 um - 3 um;

[0027] Ⅲ. The thickness of the N waveguide layer is 90 nm - 120 nm;

[0028] Ⅳ. The thickness of the P waveguide layer is 90 nm - 120 nm;

[0029] Ⅴ. The thickness of the P confinement layer is 1 um - 3 um;

[0030] Ⅵ. The thickness of the ohmic contact layer is 140 nm;

[0031] Ⅶ. The thickness of the insulating layer is 50 nm - 100 μm;

[0032] A preparation method of a Y-type high-power single-mode semiconductor laser, comprising the following steps:

[0033] (1) Prepare a substrate. The laser substrate is a GaAs crystal with a crystal orientation of (100) and a substrate thickness of 500 μm;

[0034] (2) Use MOCVD equipment on the substrate to grow a transition layer, an N confinement layer, an N waveguide layer, a quantum well active layer, and a P waveguide layer in sequence from bottom to top;

[0035] (3) Grow a P confinement layer above the P waveguide layer. The P confinement layer is divided into two layers, both made of AlGaInP. A GaInP barrier layer is grown between the two layers. The GaInP barrier layer is located 200 nm above the interface position between the P confinement layer and the P waveguide layer. An AlGaInP barrier layer with a thickness of 60 nm is grown on the top of the upper P confinement layer;

[0036] (4) An ohmic contact layer is grown on the AlGaInP barrier layer;

[0037] (5) After the above epitaxial wafer growth is completed, first spin-coat photoresist on the surface of the ohmic contact layer, perform ultraviolet lithography, development, etching, and photoresist removal, and etch away the ohmic contact layer except for the position above the ridge waveguide according to a preset pattern; Spin-coat photoresist again, perform ultraviolet lithography, development, etching, and photoresist removal, and etch out the ridge waveguide, grooves, deep grooves, and shoulder structures according to a preset structural pattern;

[0038] (7) Grow an insulating layer on the wafer with the above-prepared structure using PECVD technology;

[0039] (8) After the growth of the insulating layer is completed, spin-coat photoresist on its surface, perform ultraviolet lithography, development, etching, and photoresist removal, etch away the insulating layer on the upper side of the ridge waveguide, and leave windows exposing the grooves, ridge waveguide, and ohmic contact layer;

[0040] (9) Spin-coat photoresist on the surface, perform ultraviolet lithography and development, retain part of the photoresist according to a preset structural pattern, deposit a P-side metal layer on the surface using electron beam evaporation coating technology, and then use the lift-off technology to strip off the photoresist at the boundary and the redundant part of the P-side metal layer;

[0041] (10) Thinning and polishing are performed on the side of the substrate away from the P-side metal. First, thin the thickness of the substrate 1 to 100 - 120 μm, and then deposit an N-side metal on the thinned and polished side;

[0042] (11) Cleave, coat, and package the wafer to fabricate a semiconductor laser.

[0043] The beneficial effects of the present invention are as follows:

[0044] 1. In the present invention, the conventional ridge waveguide is gradually divided into two identical branched ridge waveguides after being guided, and the overall structure is a Y-shaped structure. The symmetric branches on the rear side of the Y-shaped waveguide are called the symmetric arms of the Y-shaped waveguide. Light within the Y-shaped structure can achieve gain oscillation. The length of the optical oscillation loop is significantly longer than that of the conventional ridge waveguide semiconductor laser, and simultaneous gain can be achieved. Beam combination is performed at the ridge waveguide junction to enhance the overall gain efficiency of the device and increase the laser power. At the same time, there is a deep groove structure between the two symmetric arms of the Y-shaped waveguide to isolate the optical interference between the two symmetric branched waveguides.

[0045] 2. The width of the ridge waveguide near the light output surface of the present invention is widened and tapered. This tapered structure is used to expand the optical field of the laser, reduce the energy density at the light output surface, and reduce the probability of damage. Moreover, through the transmission of the output light in the wide waveguide region, the gain pressure of the fundamental mode will be further enhanced, which is beneficial for the laser to achieve single-mode spot output at high power. Description of the Drawings

[0046] Figure 1 It is a schematic structural diagram of the Y-shaped high-power single-mode semiconductor laser in the embodiment of the present invention. For ease of observation, the ohmic contact layer, P-side metal layer, and insulating layer of the laser are removed in the figure;

[0047] Figure 2 It is a cross-sectional view of the Y-shaped high-power single-mode semiconductor laser in the embodiment of the present invention at the wide waveguide;

[0048] Figure 3 It is a cross-sectional view of the Y-shaped high-power single-mode semiconductor laser in the embodiment of the present invention at the symmetric arm of the Y-shaped waveguide;

[0049] Figure 4 It is the transmission situation of the fundamental mode optical field within the ridge waveguide structure of the Y-shaped high-power single-mode semiconductor laser;

[0050] Figure 5 It is a schematic structural diagram of the conventional ridge waveguide semiconductor laser;

[0051] Figure 6 It is a cross-sectional view of the conventional ridge waveguide semiconductor laser;

[0052] Figure 7 It is the transmission situation of the fundamental mode optical field within the ridge waveguide structure of the conventional ridge waveguide semiconductor laser;

[0053] Figure 8Comparison of near-field optical intensity distributions between a Y-shaped high-power single-mode semiconductor laser and a conventional ridge waveguide semiconductor laser;

[0054] In the figure: 1, transition layer; 2, N confinement layer; 3, N waveguide layer; 4, quantum well active layer; 5, P waveguide layer; 6, P confinement layer; 7, ridge waveguide; 8, ohmic contact layer; 9, P-side metal layer; 10, groove; 11, shoulder; 12, insulating layer; 13, deep groove; 14, symmetric arms of the Y-shaped waveguide; 15, wide waveguide region; 16, substrate. Specific embodiments

[0055] The present invention will be further described below through examples in conjunction with the accompanying drawings, but is not limited thereto.

[0056] Example 1:

[0057] A Y-shaped high-power single-mode semiconductor laser includes a substrate 16, a transition layer 1, an N confinement layer 2, an N waveguide layer 3, a quantum well active layer 4, a P waveguide layer 5, and a P confinement layer 6 that are sequentially connected together from bottom to top. Raised shoulders 11 are symmetrically arranged on the surface of the P confinement layer. A ridge waveguide 7 is arranged between the shoulders 11. The ridge waveguide 7 is gradually divided into two branch ridge waveguides from the light-emitting side to the other side, and the overall is a Y-shaped structure. The symmetric branches on the other side of the ridge waveguide are the symmetric arms 14 of the Y-shaped waveguide, which can achieve gain simultaneously, and beam combination is performed at the ridge waveguide junction to enhance the overall gain efficiency of the device and increase the power of the laser. At the same time, a deep groove 13 is arranged between the two symmetric arms 14 of the Y-shaped waveguide to isolate the optical interference between the two symmetric branch waveguides. The length of the deep groove 13 is 1 / 3 of the length of the laser, the width is 10 μm, and the depth of the deep groove penetrates through the P confinement layer, the P waveguide layer, the quantum well active layer, the N waveguide layer, the N confinement layer, and reaches the substrate. The width of the ridge waveguide on the light-emitting side of the laser is widened to 30 μm, presenting a cone shape, and the length of the cone region is 15 μm. This cone structure is used to expand the optical field of the laser, reduce the energy density of the light-emitting surface, and reduce the probability of damage to the cavity surface of the laser. A groove 10 is formed between the shoulder and the ridge waveguide. Insulating layers 12 are arranged in the groove 10 and on the upper side of the shoulder. An ohmic contact layer 8 is arranged on the top of the ridge waveguide, and a P-side metal layer 9 is arranged above the insulating layer 12 and the ohmic contact layer 8 to facilitate the formation of a conductive contact area between the P-side metal layer 9 and the ohmic contact layer 8.

[0058] The insulating layer covers the top and side of the shoulder. The insulating layer on the shoulder is integrally in a shape like the Chinese character 'ji'. The material of the insulating layer is SiO2, and its thickness is 100 nm.

[0059] The substrate 16 is made of GaAs material. The N confinement layer 2 is made of AlInP material, and the thickness of the N-type confinement layer 2 is 1.05 um, with the dopant being Si. The N waveguide layer 3 is made of AlGaInP material, and the thickness of the N waveguide layer is 0.1 um. The quantum well active layer 4 is a layered structure formed by sequentially stacking GaInP, AlGaInP, and GaInP, with a thickness of 15 nm. The P waveguide layer 5 is made of AlGaInP material, and the thickness of the P waveguide layer 5 is 100 nm. The P confinement layer 6 is made of AlInP material, and the thickness of the P confinement layer 6 is 1.2 um. The dopant in the P confinement layer 6 is Mg, and its doping concentration is 1E20 / cm 3 . The thickness of the P-side metal layer is 0.7 um, and the material of the P-side metal layer is an alloy formed by Ti and Pt. The material of the ohmic contact layer is highly doped GaAs material with C, the C doping concentration is 1e18, and the thickness of the ohmic contact layer is 140 nm.

[0060] Reference Figure 1 And Figure 5 , where the Figure 1 is the laser structure of the present invention. And Figure 5 Compared with the conventional ridge waveguide semiconductor laser shown in

[0061] , the characteristics of the laser in this embodiment are as follows: As the ridge waveguide 7 extends towards the rear of the laser, it divides into two symmetric branches, called the Y-shaped waveguide symmetric arms 14. There is a deep groove 13 between the Y-shaped waveguide symmetric arms 14, and the internal space of the deep groove 13 is filled with an insulating layer 12.

[0062] The materials, dimensions, dopants, etc. of the various structural layers shown in this embodiment include but are not limited to the above descriptions. Those skilled in the art can select or adjust according to the actual requirements. This embodiment is mainly to more clearly and comprehensively display the structure of the above semiconductor laser.

[0063] In this embodiment, the ridge waveguide 7 gradually branches into two identical branch ridge waveguides backward to form the symmetric arms 14 of the Y-shaped waveguide. The overall region can achieve gain. According to the general laws and common sense of lasers, the length of the gain region is proportional to the output light power. The ridge waveguide 7 and the symmetric arms 14 of the Y-shaped waveguide have common gain and are combined at the junction point, which can effectively enhance the overall gain efficiency of the device and increase the laser power. At the same time, there is a deep groove structure between the two symmetric arms 14 of the Y-shaped waveguide to isolate the optical interference between the two symmetric branch waveguides. The width of the ridge waveguide 7 near the light output surface of the laser gradually widens to form a wide waveguide region 15. The wide waveguide region 15 is conical. The wide waveguide region 15 is used to expand the laser optical field, reduce the energy density at the light output surface, and reduce the damage probability when achieving high-power output.

[0064] Embodiment 2:

[0065] A method for manufacturing the Y-shaped high-power single-mode semiconductor laser described in Embodiment 1, and the specific process is as follows:

[0066] (1) The laser substrate 16 is a GaAs crystal with a crystal orientation of (100) and a substrate thickness of 500 μm;

[0067] (2) A transition layer is grown on the substrate using an MOCVD device. The material of the transition layer is Si-doped GaAs with a thickness of 200 nm;

[0068] (3) An N confinement layer 2 is grown on the transition layer using an MOCVD device. The material of the N confinement layer 2 is Si-doped AlInP with a doping concentration of 1 - 4E18 / cm 3 ;

[0069] (4) An N waveguide layer 3 is grown on the N confinement layer 2 using an MOCVD device. The material is AlGaInP. The thickness of the N waveguide layer 3 is 0.1 μm. By adjusting the composition of Al, the AlGaInP shows a gradient distribution along the direction perpendicular to the growth plane, and the composition of Al is higher in the direction away from the GaAs substrate;

[0070] (5) A quantum well active layer 4 is grown above the N waveguide layer 3;

[0071] (6) A P waveguide layer 5 is grown above the quantum well active layer 4. The material of the P waveguide layer 5 is AlGaInP with a thickness of 100 nm. The composition of Al in the material shows a gradient distribution along the direction perpendicular to the growth plane, and the composition of Al is higher in the direction away from the GaAs substrate;

[0072] (7) A P confinement layer 6 is grown above the P waveguide layer 5. The P confinement layer is divided into two layers, both made of AlGaInP, and a GaInP barrier layer is grown between the two layers. The GaInP barrier layer is located 200 nm above the interface between the P confinement layer and the P waveguide layer. An AlGaInP barrier layer with a thickness of 60 nm is grown on the top of the upper P confinement layer.

[0073] (8) An ohmic contact layer 8 is grown on the P confinement layer 6. The material of the ohmic contact layer is highly doped GaAs, and its thickness is 140 nm.

[0074] (9) After the above epitaxial wafer growth is completed, photoresist is spin-coated on the surface of the ohmic contact layer 8, and ultraviolet lithography, development, etching, and photoresist removal are carried out. The ohmic contact layer 8 except for the ridge waveguide is etched away according to the preset pattern.

[0075] (10) Spin-coat photoresist again, and carry out ultraviolet lithography, development, etching, and photoresist removal. Etch out the ridge waveguide 7, groove 10, and shoulder 11 structures according to the preset structure pattern.

[0076] (11) Spin-coat photoresist again and carry out the steps of ultraviolet lithography, development, etching, and photoresist removal. Etch out the deep groove 13, Y-shaped waveguide symmetric arms 14, and wide waveguide region 15 according to the preset structure pattern.

[0077] (12) The insulating layer 12 is grown on the wafer with the above-prepared structure by PECVD technology. The material of the insulating layer 12 is SiO2, and its thickness is 100 nm.

[0078] (13) After the growth of the insulating layer 12 is completed, photoresist is spin-coated on its surface, and ultraviolet lithography, development, etching, and photoresist removal steps are carried out. The insulating layer 12 above the ridge waveguide 7 is etched away, and the windows of the ohmic contact layer 8 above the ridge waveguide 7, Y-shaped waveguide symmetric arms 14, and wide waveguide region 15 are reserved.

[0079] (14) Spin-coat photoresist on the surface, carry out ultraviolet lithography and development, retain part of the photoresist according to the preset structure pattern, evaporate the P-side metal layer 9 on the surface by electron beam evaporation coating technology, then thin and polish the side of the substrate 16 away from the P-side metal, reduce the substrate thickness to 100 - 120 um, and evaporate the N-side metal on the thinned and polished side.

[0080] (15) Cleave, coat, and package the wafer to prepare a semiconductor laser.

[0081] Comparative Example 1

[0082] The comparative example provides a preparation method of a conventional ridge waveguide semiconductor laser, the specific process of which is the same as that described in Embodiment 2, except that lithography, development, and etching are carried out according to a preset structural pattern to form the ridge waveguide 7, groove 10, and shoulder 11 structures. There is no deep groove 13, Y-shaped waveguide symmetric arm 14, and wide waveguide region 15 in the comparative example. At the same time, after growing the insulating layer 12, in the comparative example, it is not necessary to precisely etch away the insulating layer 12 directly above the ridge waveguide 7, but to etch away the insulating layer 12 directly above the ridge waveguide 7, on both sides of the ridge waveguide 7, and in the groove 10.

[0083] Performance test experiment

[0084] The performance of the Y-shaped high-power single-mode semiconductor laser prepared in Embodiment 2 above was tested, and the results of calculation and simulation using the actual device parameters are as Figure 4 , Figure 8 shown. Among them, Figure 4 is the transmission situation diagram of the fundamental mode optical field in the Y-shaped high-power single-mode semiconductor laser. It can be seen that light can achieve gain oscillation in the Y-shaped structure. Figure 7 is the transmission situation of the fundamental mode optical field in the ridge waveguide structure of the conventional ridge waveguide semiconductor laser. By comparing with the conventional ridge waveguide semiconductor laser prepared in Comparative Example 1 above, Figure 4 the length of the optical oscillation loop is significantly greater than Figure 7 , so the gain performance of the Y-shaped high-power single-mode semiconductor laser is significantly stronger than that of the conventional ridge waveguide semiconductor laser.

[0085] From the Figure 8 comparison, it can be seen that the light field distribution of the Y-shaped high-power single-mode semiconductor laser is significantly larger than that of the conventional ridge waveguide semiconductor laser. As is known from general knowledge, the smaller the near-field size of light, the higher the energy density at the same power, and the more likely it is to cause damage.

[0086] Comparing Figure 4 with Figure 7 it can be found that when light is combined at the junction of the ridge waveguide 7 and the Y-shaped waveguide symmetric arm, the structure has little influence on the coupled light, effectively reducing the transmission loss and improving the efficiency of the device. And through the transmission of the output light in the wide waveguide region 15, the gain pressure of the fundamental mode will be further enhanced, which is beneficial to the single-mode spot output of the laser at high power.

[0087] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A Y-type high-power single-mode semiconductor laser, characterized in that, It includes a substrate, a transition layer, an N confinement layer, an N waveguide layer, a quantum well active layer, a P waveguide layer, and a P confinement layer that are connected together in sequence from bottom to top. Raised shoulders are symmetrically arranged on the surface of the P confinement layer, and a ridge waveguide is arranged between the shoulders. The ridge waveguide is gradually divided into two branch ridge waveguides from the light-emitting side to the other side, and the overall structure is a Y-shaped structure. The symmetric branches on the other side of the ridge waveguide are Y-shaped waveguide symmetric arms. A deep groove is arranged between the two Y-shaped waveguide symmetric arms. The width of the ridge waveguide on the side of the laser light-emitting surface is widened, presenting a conical shape. A groove is formed between the shoulder and the ridge waveguide, and insulating layers are arranged in the groove and on the upper side of the shoulder. An ohmic contact layer is arranged on the top of the ridge waveguide, and a P-side metal layer is arranged above the insulating layer and the ohmic contact layer.

2. The Y-type high-power single-mode semiconductor laser according to claim 1, characterized in that, The cross-section of the ridge waveguide is rectangular or trapezoidal, and the ridge waveguide and the shoulder are integrally formed by the P confinement layer.

3. The Y-shaped high-power single-mode semiconductor laser according to claim 1, characterized in that, Among them, the width of the ridge waveguide is 2 μm - 5 μm, and the height of the ridge waveguide is the same as the depth of the groove, which is 0.1 μm - 5 μm.

4. The Y-shaped high-power single-mode semiconductor laser according to claim 1, wherein, The quantum well active layer is a layered structure formed by sequentially stacking GaInP, AlGaInP, and GaInP, and the thickness of the quantum well active layer is 1 nm - 40 nm.

5. The Y-shaped high-power single-mode semiconductor laser according to claim 4, characterized in that, The insulating layer covers the top and side of the shoulder, and the insulating layer on the shoulder is integrally in a shape like the Chinese character "ji".

6. The Y-shaped high-power single-mode semiconductor laser according to claim 1, wherein The length of the deep groove is 1 / 3 of the length of the laser, the width is 10 μm, and the depth of the deep groove penetrates through the P confinement layer, the P waveguide layer, the quantum well active layer, the N waveguide layer, the N confinement layer, and reaches the substrate.

7. The Y-type high-power single-mode semiconductor laser according to claim 1, characterized in that, The conical ridge waveguide on the side of the laser light-emitting surface is widened to 30 μm, and the length of the conical region is 15 μm.

8. The Y-shaped high-power single-mode semiconductor laser according to claim 5, characterized in that, The Y-shaped high-power single-mode semiconductor laser includes one of the following schemes: Ⅰ. The P-side metal layer is at least two of Ti, Pt, Au, Ge, Ni, Cr, Sn; Ⅱ. The substrate material is at least one of GaAs, InP, Si; Ⅲ. The material of the N confinement layer is at least one of GaAs, GaInP, AlInP, AlGaInP, AlGaAs, AlGaAsP, InGaAsP; Ⅳ. The material of the N waveguide layer is at least one of GaAs, GaInP, AlInP, AlGaInP, AlGaAs, AlGaAsP, InGaAsP; Ⅴ. The material of the P waveguide layer is at least one of GaAs, GaInP, AlInP, AlGaInP, AlGaAs, AlGaAsP, InGaAsP; Ⅵ. The material of the P confinement layer is at least one of GaAs, GaInP, AlInP, AlGaInP, AlGaAs, AlGaAsP, InGaAsP; Ⅶ. The material of the insulating layer is at least one of SiO2, Si3N4, AlN; Ⅷ. The material of the ohmic contact layer is C highly doped GaAs material, and the C doping concentration is 1e18.

9. The Y-type high-power single-mode semiconductor laser according to claim 8, characterized in that, The Y-shaped high-power single-mode semiconductor laser includes one of the following schemes: Ⅰ. The thickness of the P-side metal layer is 0.2 μm - 2 μm; Ⅱ. The thickness of the N confinement layer is 1 μm - 3 μm; Ⅲ. The thickness of the N waveguide layer is 90 nm - 120 nm; Ⅳ. The thickness of the P waveguide layer is 90 nm - 120 nm; Ⅴ. The thickness of the P confinement layer is 1 um - 3 um; Ⅵ. The thickness of the ohmic contact layer is 140 nm; Ⅶ. The thickness of the insulating layer is 50 nm - 100 um.

10. A method for preparing a Y-shaped high-power single-mode semiconductor laser as described in claim 9, characterized in that, The steps are as follows: (1) Prepare a substrate. The laser substrate is a GaAs crystal with a crystal orientation of (100) and a substrate thickness of 500 um; (2) Use MOCVD equipment on the substrate to grow a transition layer, an N confinement layer, an N waveguide layer, a quantum well active layer, and a P waveguide layer from bottom to top in sequence; (3) Grow a P confinement layer above the P waveguide layer. The P confinement layer is divided into two layers, both of which are AlGaInP. A GaInP barrier layer is grown between the two layers. The GaInP barrier layer is located 200 nm above the interface position between the P confinement layer and the P waveguide layer. An AlGaInP barrier layer with a thickness of 60 nm is grown on the top of the upper P confinement layer; (4) An ohmic contact layer is grown on the AlGaInP barrier layer; (5) After the above epitaxial wafer growth is completed, first spin-coat photoresist on the surface of the ohmic contact layer, perform ultraviolet lithography, development, etching, and resist stripping, and etch away the ohmic contact layer except for the position above the ridge waveguide according to a preset pattern; Spin-coat photoresist again, perform ultraviolet lithography, development, etching, and resist stripping, and etch out the ridge waveguide, groove, deep groove, and shoulder structure according to a preset structural pattern; (7) Grow an insulating layer on the wafer with the above-prepared structure using PECVD technology; (8) After the growth of the insulating layer is completed, spin-coat photoresist on its surface, perform ultraviolet lithography, development, etching, and resist stripping, etch away the insulating layer on the upper side of the ridge waveguide, and leave a window exposing the groove, ridge waveguide, and ohmic contact layer; (9) Spin-coat photoresist on the surface, perform ultraviolet lithography and development, retain part of the photoresist according to a preset structural pattern, evaporate and deposit a P-side metal layer on the surface using electron beam evaporation coating technology, and then use the lift-off technology to strip away the photoresist at the boundary and the excess P-side metal layer in the region; (10) Thin and polish the side of the substrate away from the P-side metal. First, thin the thickness of the substrate 1 to 100 - 120 um, and then evaporate and deposit an N-side metal on the thinned and polished side; (11) Cleave, coat, and package the wafer to fabricate a semiconductor laser.

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