Double-absorption-loss type high-power single-mode semiconductor laser and preparation method thereof

Abstract

The invention discloses a double-absorption loss type high-power single-mode semiconductor laser and a preparation method thereof, and the laser comprises a main oscillation waveguide, a left super-accompanying waveguide, a right super-accompanying waveguide, a conical gain waveguide and an absorption waveguide which are disposed on a same epitaxial structure, and the left super-accompanying waveguide and the right super-accompanying waveguide are located at the left and right sides of the main oscillation waveguide respectively. A super-symmetric waveguide is formed together; the conical gain waveguide is located at the front end of the super-symmetric waveguide; the absorption waveguide is located at the front end of the conical gain waveguide; wherein the left super-accompanying waveguide and the right super-accompanying waveguide are used for losing a high-order transverse mode in multi-transverse-mode laser generated by the main oscillation waveguide; and the absorption waveguide is used for losing the residual high-order transverse mode in the conical gain waveguide. On the basis, high-power and high-beam-quality single-mode laser output can be obtained.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor lasers, and in particular to a double-absorption loss type high-power single-mode semiconductor laser and a preparation method thereof. Background Art

[0002] With the development of semiconductor laser technology, the application of lasers covers the fields of optical pumping, laser medical cosmetology, optical communication, etc. Among them, in order to solve the problem that edge-emitting semiconductor lasers are difficult to balance power and beam quality, researchers have proposed the structure of a tapered laser. The tapered laser includes a main oscillator waveguide and a tapered gain waveguide. The main oscillator waveguide provides fundamental mode seed light, and the tapered gain waveguide provides power amplification.

[0003] However, as the gain of the tapered laser increases, high-order transverse modes will appear in the main oscillator waveguide, and other high-order transverse modes will appear in the tapered gain waveguide, causing mode confusion in the laser. At present, the high-order transverse modes are mainly filtered by deeply etching the leakage groove structure on both sides of the main oscillator waveguide, but this may cause light leakage in the laser, poor stability, and high process difficulty. Summary of the invention

[0004] In view of the shortcomings of the existing problems, the present invention provides a double-absorption loss type high-power single-mode semiconductor laser and a preparation method thereof.

[0005] The present invention discloses a double-absorption loss type high-power single-mode semiconductor laser, comprising: a main oscillation waveguide, a left super-slave waveguide, a right super-slave waveguide, a tapered gain waveguide and an absorption waveguide arranged on the same epitaxial structure, wherein the left super-slave waveguide and the right super-slave waveguide are respectively located on the left and right sides of the main oscillation waveguide to form a supersymmetric waveguide together; the tapered gain waveguide is located at the front end of the supersymmetric waveguide, and the absorption waveguide is located at the front end of the tapered gain waveguide; wherein,

[0006] The main oscillator waveguide provides a seed laser, and the high-order transverse mode modes in the multi-transverse mode laser generated by the main oscillator waveguide are actively lost for the first time through the left super-slave waveguide and the right super-slave waveguide to form a fundamental transverse mode laser, so as to reduce the lateral divergence angle of the laser beam; the tapered gain waveguide is used to realize laser power amplification output; the absorption waveguide is used to lose the residual high-order transverse mode in the tapered gain waveguide for the second time, so as to finally obtain a high-power and high-beam quality fundamental transverse mode laser.

[0007] As a further improvement of the present invention, the epitaxial structure includes a substrate, an N-face confinement layer, an N-face waveguide layer, an active region, a P-face waveguide layer, a P-face confinement layer and a P-face ohmic contact layer arranged in sequence from bottom to top, an N-face electrode is formed on the lower surface of the substrate, and an insulating layer and a P-face electrode are formed in sequence on the upper surface of the P-face ohmic contact layer; wherein the main oscillation waveguide, the left super-slave waveguide and the right super-slave waveguide are vertically etched to the P-face waveguide layer, and the tapered gain waveguide is vertically etched to the P-face confinement layer.

[0008] As a further improvement of the present invention, the insulating layer includes one of silicon dioxide and silicon nitride, the P-side electrode includes one or more of gold, platinum, and titanium, and the N-side electrode includes one or more of germanium, niobium, and gold.

[0009] As a further improvement of the present invention, the lateral dimension of the main oscillator waveguide is greater than the lateral single-mode cutoff condition There are three transverse mode modes: fundamental transverse mode TE0, first-order transverse mode TE1, and second-order transverse mode TE2;

[0010] Where w is the width of the main oscillator waveguide, λ is the wavelength of free space light, and n eff The equivalent refractive index of the main oscillation waveguide, n L is the equivalent refractive index after etching on both sides of the main oscillation waveguide, the propagation constant of the fundamental transverse mode TE0 existing in the main oscillation waveguide is β0, the propagation constant of the first-order transverse mode TE1 is β1, and the propagation constant of the second-order transverse mode TE2 is β2;

[0011] Furthermore, the width of the master oscillation waveguide is 4-6 μm.

[0012] As a further improvement of the present invention, the longitudinal dimension of the main oscillator waveguide is determined by the longitudinal single-mode cutoff condition. get;

[0013] Wherein, d is the etching depth (longitudinal dimension) of the main oscillation waveguide, λ is the wavelength of free space light, n1 is the equivalent refractive index of the P-plane confinement layer, and n2 is the equivalent refractive index of the P-plane waveguide layer;

[0014] Furthermore, the etching depth of the main oscillation waveguide is 1 to 1.2 μm.

[0015] As a further improvement of the present invention, the lateral dimensions w1 and w2 of the left super-companion waveguide and the right super-companion waveguide are determined by finite element method calculation;

[0016] Among them, the propagation constant β0 of the fundamental transverse mode TE0 of the left super companion waveguide with a width of w1 is equal to the propagation constant β1 of the first-order transverse mode in the main oscillation waveguide, and the propagation constant β1 of the first-order transverse mode TE1 of the right super companion waveguide with a width of w2 is equal to the propagation constant β2 of the second-order transverse mode in the main oscillation waveguide;

[0017] Furthermore, the width w1 of the left super-slave waveguide is 2.1 μm, and the width w2 of the right super-slave waveguide is 2.6 μm.

[0018] As a further improvement of the present invention, the longitudinal dimensions of the left super-companion waveguide and the right super-companion waveguide are determined by the longitudinal single-mode cutoff condition. get;

[0019] Wherein, d1 is the etching depth of the left super-slave waveguide or the right super-slave waveguide, λ is the wavelength of the free-space light, n1 is the equivalent refractive index of the P-plane confinement layer, and n2 is the equivalent refractive index of the P-plane waveguide layer;

[0020] Furthermore, the etching depth of the left super-slave waveguide or the right super-slave waveguide is 1 to 1.2 μm.

[0021] As a further improvement of the present invention, the cone angle of the tapered gain waveguide should be less than or equal to the fundamental mode diffraction angle, and the fundamental mode diffraction angle is given by θ=λ[2tan -1 (b / (1-b)) 1 / 2 ] / n eff-n wget;

[0022] Where w is the width of the main oscillation waveguide, n eff-n is the equivalent refractive index when the width of the main oscillation waveguide approaches infinity, n eff is the equivalent refractive index of the main oscillation waveguide, n3 is the bulk refractive index of the P-plane waveguide layer;

[0023] Furthermore, the tapered gain waveguide has a taper angle of 3.8-4.2° and an etching depth of 0.5-1 μm.

[0024] As a further improvement of the present invention, the dimensions of the absorption waveguide are: 100-150 μm in length, 10-20 μm in width, and a non-injection region of 2-5 μm is left in the middle;

[0025] Furthermore, the absorption waveguide is selected to be H + Ion implantation, the implantation energy is 320keV, the implantation dose is 8×10 14 / cm -2 .

[0026] Also disclosed is a method for preparing a double-absorption loss type high-power single-mode semiconductor laser, comprising:

[0027] Selecting a substrate;

[0028] The epitaxial growth is performed by using a metal organic compound vapor deposition technology, and an N-side limiting layer, an N-side waveguide layer, an active region, a P-side waveguide layer, a P-side limiting layer and a P-side ohmic contact layer are sequentially grown from bottom to top on the surface of the substrate to form an epitaxial structure;

[0029] Using ultraviolet exposure technology and inductively coupled plasma dry etching technology, the main oscillation waveguide, left super companion waveguide and right super companion waveguide are deeply etched on the epitaxial structure;

[0030] Using ultraviolet exposure technology and inductively coupled plasma dry etching technology, a tapered gain waveguide is shallowly etched on the epitaxial structure;

[0031] Using ion implantation technology, H is implanted into the epitaxial structure. + ions, forming an absorption waveguide;

[0032] Using plasma enhanced vapor chemical deposition technology, an insulating layer is deposited on the epitaxial structure;

[0033] Using photolithography technology, the P-surface electrode windows of the main oscillator waveguide and the tapered gain waveguide are etched;

[0034] The magnetron sputtering technology is used to sputter the P-side electrode on the epitaxial structure;

[0035] Thinning and polishing substrates;

[0036] sputtering an N-side electrode on the back side of the substrate using a magnetron sputtering technique;

[0037] The formed double-absorption loss type high-power single-mode semiconductor laser is cleaved, wire-bonded and packaged.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The present invention designs a left super-slave waveguide and a right super-slave waveguide on both sides of the main oscillation waveguide, which can effectively consume the high-order modes in the multi-transverse mode laser generated by the main oscillation waveguide, generate fundamental transverse mode laser output, and greatly reduce the lateral divergence angle of the light beam; the tapered gain waveguide amplifies the power output of the fundamental transverse mode laser, and the absorption waveguide further consumes the residual high-order transverse modes existing in the tapered gain waveguide, thereby obtaining a single-mode laser output with high power and high beam quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the three-dimensional structure of the double-absorption loss type high-power single-mode semiconductor laser disclosed in the present invention;

[0041] Figure 2 It is a schematic diagram of the epitaxial structure of the double-absorption loss type high-power single-mode semiconductor laser disclosed in the present invention;

[0042] Figure 3 This is a light field mode diagram of the supersymmetric waveguide in the double-absorption loss type high-power single-mode semiconductor laser disclosed in the present invention.

[0043] In the figure:

[0044] 1. Left super companion waveguide; 2. Right super companion waveguide; 3. Main oscillation waveguide; 4. Conical gain waveguide; 5. Absorption waveguide; 6. N-side electrode; 7. Substrate; 8. N-side confinement layer; 9. N-side waveguide layer; 10. Active region; 11. P-side waveguide layer; 12. P-side confinement layer; 13. P-side ohmic contact layer; 14. Insulation layer; 15. P-side electrode. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0047] like Figure 1 As shown, the present invention provides a double-absorption loss type high-power single-mode semiconductor laser, comprising: a main oscillation waveguide 3, a left super-slave waveguide 1, a right super-slave waveguide 2, a tapered gain waveguide 4 and an absorption waveguide 5 which are sequentially arranged on the same epitaxial structure; the left super-slave waveguide 1 and the right super-slave waveguide 2 are respectively located on the left and right sides of the main oscillation waveguide 3, and together form a supersymmetric waveguide; the tapered gain waveguide 4 is located at the front end of the supersymmetric waveguide, and the absorption waveguide 5 is located at the front end of the tapered gain waveguide 4.

[0048] like Figure 2 As shown, the epitaxial structure of the present invention includes a GaAs substrate 7, an N-face confinement layer 8, an N-face waveguide layer 9, an active region 10, a P-face waveguide layer 11, a P-face confinement layer 12 and a P-face ohmic contact layer 13 arranged in sequence from bottom to top, an N-face electrode 6 is formed on the back of the substrate 7, and an insulating layer 14 and a P-face electrode 15 are formed in sequence on the front of the P-face ohmic contact layer; wherein the main oscillation waveguide 3, the left super companion waveguide 1 and the right super companion waveguide 2 are vertically etched to the P-face waveguide layer 11, and the tapered gain waveguide 4 is vertically etched to the P-face confinement layer 12. Further, the insulating layer 14 of the present invention includes but is not limited to one of silicon dioxide and silicon nitride; the P-face electrode 15 is but is not limited to one or more of gold, platinum and titanium; and the N-face electrode 6 is but is not limited to one or more of germanium, niobium and gold.

[0049] The present invention designs a left super-slave waveguide 1 and a right super-slave waveguide 2 on both sides of a main oscillator waveguide 3, which can effectively consume the high-order modes in the multi-transverse mode laser generated by the main oscillator waveguide 3, generate a fundamental transverse mode laser output, and greatly reduce the lateral divergence angle of the light beam; the tapered gain waveguide 4 amplifies the power output of the fundamental transverse mode laser, and the absorption waveguide 5 further consumes the residual high-order transverse modes existing in the tapered gain waveguide 4, thereby obtaining a single-mode laser output with high power and high beam quality.

[0050] like Figure 3 As shown, the modes except the fundamental transverse mode in the main oscillation waveguide 3 of the present invention correspond to the modes in the super companion waveguide respectively; wherein, the propagation constant β1 of the first-order transverse mode in the main oscillation waveguide 3 is equal to the propagation constant β0 of the fundamental transverse mode TE0 of the left super companion waveguide 1 with a width of w1, and the propagation constant β2 of the second-order transverse mode in the main oscillation waveguide 3 is equal to the propagation constant β1 of the first-order transverse mode TE1 of the right super companion waveguide 2 with a width of w2; therefore, when the main oscillation waveguide 3 is amplified, the high-order transverse modes will be lost by the super companion waveguide, while the fundamental transverse mode loss in the main oscillation waveguide 3 is not as good as the high-order transverse mode, and occupies a dominant position in the laser mode.

[0051] Specific:

[0052] The lateral dimension of the master oscillator waveguide 3 of the present invention is greater than the lateral single-mode cutoff condition There are three transverse mode modes: fundamental transverse mode TE0, first-order transverse mode TE1, and second-order transverse mode TE2; where w is the width of the main oscillation waveguide, λ is the wavelength of free space light, and n eff The equivalent refractive index of the main oscillation waveguide, n L For the equivalent refractive index after etching on both sides of the main oscillation waveguide, the propagation constant of the fundamental transverse mode TE0 in the main oscillation waveguide is β0, the propagation constant of the first-order transverse mode TE1 is β1, and the propagation constant of the second-order transverse mode TE2 is β2; further, the width of the main oscillation waveguide 3 is 4 to 6 μm.

[0053] The longitudinal dimension of the master oscillator waveguide of the present invention is determined by the longitudinal single-mode cutoff condition Obtained; where d is the etching depth (longitudinal dimension) of the main oscillator waveguide, λ is the wavelength of free space light, n1 is the equivalent refractive index of the P-plane confinement layer, and n2 is the equivalent refractive index of the P-plane waveguide layer; further, the etching depth of the main oscillator waveguide 3 is 1 to 1.2 μm. .

[0054] The lateral dimensions w1 and w2 of the left super-slave waveguide 1 and the right super-slave waveguide 2 of the present invention are determined by finite element method calculation; wherein, the fundamental transverse mode TE0 propagation constant β0 of the left super-slave waveguide 1 with a width of w1 is equal to the propagation constant β1 of the first-order transverse mode in the main oscillation waveguide 3, and the first-order transverse mode TE1 propagation constant β1 of the right super-slave waveguide 2 with a width of w2 is equal to the propagation constant β2 of the second-order transverse mode in the main oscillation waveguide 3; further, the width w1 of the left super-slave waveguide 1 is 2.1μm, and the width w2 of the right super-slave waveguide 2 is 2.6μm.

[0055] The longitudinal dimensions of the left super companion waveguide 1 and the right super companion waveguide 2 of the present invention are determined by the longitudinal single-mode cutoff condition. Obtained; wherein, d1 is the etching depth of the left super-slave waveguide 1 or the right super-slave waveguide 2, λ is the wavelength of free space light, n1 is the equivalent refractive index of the P-plane confinement layer, and n2 is the equivalent refractive index of the P-plane waveguide layer; further, the etching depth of the left super-slave waveguide or the right super-slave waveguide is 1 to 1.2 μm.

[0056] The cone angle of the tapered gain waveguide 4 of the present invention should be less than or equal to the fundamental mode diffraction angle, and the fundamental mode diffraction angle is given by θ=λ[2tan -1 (b / (1-b)) 1 / 2 ] / n eff-n w is obtained; where w is the width of the main oscillation waveguide, n eff-n is the equivalent refractive index when the width of the main oscillation waveguide approaches infinity, n eff is the equivalent refractive index of the main oscillation waveguide, n3 is the bulk refractive index of the P-plane waveguide layer; further, the cone angle of the tapered gain waveguide is 3.8-4.2°, and the etching depth is 0.5-1 μm.

[0057] The size of the absorption waveguide 5 of the present invention is: length 100-150 μm, width 10-20 μm, and a non-injection area of ​​2-5 μm is reserved in the middle; further, the absorption waveguide is selected as H + Ion implantation, the implantation energy is 320keV, the implantation dose is 8×10 14 / cm -2 .

[0058] The present invention provides a method for preparing a double-absorption loss type high-power single-mode semiconductor laser, comprising:

[0059] Step 1, selecting a substrate 7;

[0060] Step 2: epitaxial growth is performed using metal organic compound vapor deposition technology to sequentially grow an N-face confinement layer 8, an N-face waveguide layer 9, an active region 10, a P-face waveguide layer 11, a P-face confinement layer 12 and a P-face ohmic contact layer 13 on the surface of a substrate 7 from bottom to top to form an epitaxial structure;

[0061] Step 3, using ultraviolet exposure technology and inductively coupled plasma dry etching technology to deeply etch the main oscillation waveguide 3, the left super companion waveguide 1 and the right super companion waveguide 2 on the epitaxial structure;

[0062] Step 4: using ultraviolet exposure technology and inductively coupled plasma dry etching technology to shallowly etch the tapered gain waveguide 4 on the epitaxial structure;

[0063] Step 5: Using ion implantation technology, H+ ions are implanted into the epitaxial structure to form an absorption waveguide 5;

[0064] Step 6: using plasma enhanced vapor chemical deposition technology to deposit an insulating layer 14 on the epitaxial structure;

[0065] Step 7: using photolithography technology to etch the P-side electrode windows of the main oscillator waveguide 3 and the tapered gain waveguide 4;

[0066] Step 8: sputtering the P-side electrode 15 on the epitaxial structure using magnetron sputtering technology;

[0067] Step 9, thinning and polishing the substrate 7;

[0068] Step 10: sputtering an N-side electrode 6 on the back side of the substrate 7 using magnetron sputtering technology;

[0069] Step 11: cleave, wire bond and package the formed double-absorption loss-type high-power single-mode semiconductor laser.

[0070] Example:

[0071] Taking a double-absorption loss type high-power single-mode semiconductor laser with an operating wavelength of 808nm as an example, the preparation method thereof includes:

[0072] S1. Select a GaAs substrate 7 with a thickness of 300 μm to 600 μm.

[0073] S2. Epitaxial growth is performed on the GaAs substrate 7 using metal organic compound vapor deposition technology. The epitaxial layers from bottom to top are: the N-side restriction layer 8 is Al 0.52～0.55 Ga 0.48～0.45 As, doping Si concentration is 1.0×10 19 ~1.5×10 19 / cm -3 , with a thickness of 1.0μm to 1.5μm; the N-type waveguide layer 9 is Al 0.35～0.55 Ga 0.65～0.45 As, doping Si concentration is 1.0×10 17 ~1.0×10 18 / cm -3, with a thickness of 0.4μm to 0.6μm; in the active region 10, the quantum well is GaAs, with a thickness of 0.004μm, and the quantum barrier layer is Al 0.15 Ga 0.85 As, thickness is 0.006μm; P-side waveguide layer 11 is Al 0.35～0.55 Ga 0.65～0.45 As, doping concentration of Be is 1.0×10 17 ~1.0×10 18 / cm -3 , with a thickness of 0.4μm to 0.6μm; the P-side limiting layer 12 is Al 0.52～0.55 Ga 0.48～0.45 As, doping concentration of Be is 1.0×10 19 ~1.5×10 19 / cm -3 , with a thickness of 1.0 μm to 1.5 μm; the P-side ohmic contact layer 13 is GaAs, with a Be doping concentration of 1.0×10 19 / cm -3 , thickness is 0.15μm~0.2μm.

[0074] S3. Use ultraviolet exposure technology and inductively coupled plasma dry etching technology to deeply etch the main oscillation waveguide 3, the left super companion waveguide 1 and the right super companion waveguide 2, with an etching depth of 1 to 1.2 μm.

[0075] S4. Using ultraviolet exposure technology and inductively coupled plasma dry etching technology, shallowly etch the tapered gain waveguide 4, with an etching depth of 0.5 to 1 μm.

[0076] S5, using ion implantation technology, inject H + ions, the implantation energy is 320keV, and the implantation dose is 8×10 14 / cm -2 , forming an absorption waveguide 5.

[0077] S6. Using plasma enhanced vapor chemical deposition technology, deposit an insulating layer 14 with a thickness of 0.13 μm.

[0078] S7. Use photolithography technology to etch the P-surface electrode windows of the main oscillation waveguide 3 and the tapered gain waveguide 4, with an etching depth of 0.13 μm.

[0079] S8. Use magnetron sputtering technology to sputter the P-side electrode 15 on the epitaxial layer, and sputter Ti, Pt, and Au in sequence, with thicknesses of 30nm, 50nm, and 300nm, respectively.

[0080] S9, thinning and polishing the substrate 7, and the remaining substrate thickness is 100 μm to 150 μm.

[0081] S10, sputtering an N-side electrode 6 on the back side of the substrate 7 by magnetron sputtering technology, sputtering Ge, Ni, and Au in sequence, with thicknesses of 100 nm, 10 nm, and 150 nm, respectively. ;

[0082] S11. Cleavage, wire bonding and packaging of double-absorption loss type high-power single-mode semiconductor lasers.

[0083] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A double-absorption loss type high-power single-mode semiconductor laser, characterized in that: include: A main oscillation waveguide, a left super-slave waveguide, a right super-slave waveguide, a tapered gain waveguide and an absorption waveguide are arranged on the same epitaxial structure, wherein the left super-slave waveguide and the right super-slave waveguide are respectively located on the left and right sides of the main oscillation waveguide to form a supersymmetric waveguide together; the tapered gain waveguide is located at the front end of the supersymmetric waveguide, and the absorption waveguide is located at the front end of the tapered gain waveguide; wherein the left super-slave waveguide and the right super-slave waveguide are used to lose the high-order transverse mode modes in the multi-transverse mode laser generated by the main oscillation waveguide; and the absorption waveguide is used to lose the residual high-order transverse mode in the tapered gain waveguide.

2. The double-absorption loss type high-power single-mode semiconductor laser according to claim 1, characterized in that: The epitaxial structure includes a substrate, an N-face confinement layer, an N-face waveguide layer, an active region, a P-face waveguide layer, a P-face confinement layer and a P-face ohmic contact layer which are arranged in sequence from bottom to top; an N-face electrode is formed on the lower surface of the substrate, and an insulating layer and a P-face electrode are formed in sequence on the upper surface of the P-face ohmic contact layer; wherein the main oscillation waveguide, the left super-slave waveguide and the right super-slave waveguide are vertically etched to the P-face waveguide layer, and the tapered gain waveguide is vertically etched to the P-face confinement layer.

3. The double-absorption loss type high-power single-mode semiconductor laser according to claim 2, characterized in that: The insulating layer includes one of silicon dioxide and silicon nitride, the P-side electrode includes one or more of gold, platinum and titanium, and the N-side electrode includes one or more of germanium, niobium and gold.

4. The double-absorption loss type high-power single-mode semiconductor laser according to any one of claims 1 to 3, characterized in that: The lateral dimension of the main oscillator waveguide is greater than the lateral single-mode cutoff condition There are three transverse mode modes: fundamental transverse mode TE0, first-order transverse mode TE1, and second-order transverse mode TE2; Where w is the width of the main oscillator waveguide, λ is the wavelength of free space light, and n eff The equivalent refractive index of the main oscillation waveguide, n L is the equivalent refractive index after etching on both sides of the main oscillation waveguide, the propagation constant of the fundamental transverse mode TE0 existing in the main oscillation waveguide is β0, the propagation constant of the first-order transverse mode TE1 is β1, and the propagation constant of the second-order transverse mode TE2 is β2; Furthermore, the width of the master oscillation waveguide is 4-6 μm.

5. The double-absorption loss type high-power single-mode semiconductor laser according to any one of claims 1 to 3, characterized in that: The longitudinal dimension of the master oscillator waveguide is determined by the longitudinal single-mode cutoff condition get; Where d is the etching depth of the main oscillation waveguide, λ is the wavelength of free space light, n1 is the equivalent refractive index of the P-plane confinement layer, and n2 is the equivalent refractive index of the P-plane waveguide layer; Furthermore, the etching depth of the main oscillation waveguide is 1 to 1.2 μm.

6. The double-absorption loss type high-power single-mode semiconductor laser according to any one of claims 1 to 3, characterized in that: The lateral dimensions w1 and w2 of the left super-slave waveguide and the right super-slave waveguide are determined by finite element method calculation; Among them, the propagation constant β0 of the fundamental transverse mode TE0 of the left super companion waveguide with a width of w1 is equal to the propagation constant β1 of the first-order transverse mode in the main oscillation waveguide, and the propagation constant β1 of the first-order transverse mode TE1 of the right super companion waveguide with a width of w2 is equal to the propagation constant β2 of the second-order transverse mode in the main oscillation waveguide; Furthermore, the width w1 of the left super-slave waveguide is 2.1 μm, and the width w2 of the right super-slave waveguide is 2.6 μm.

7. The double-absorption loss type high-power single-mode semiconductor laser according to any one of claims 1 to 3, characterized in that: The longitudinal dimensions of the left super-companion waveguide and the right super-companion waveguide are determined by the longitudinal single-mode cutoff condition. get; Wherein, d1 is the etching depth of the left super-slave waveguide or the right super-slave waveguide, λ is the wavelength of the free-space light, n1 is the equivalent refractive index of the P-plane confinement layer, and n2 is the equivalent refractive index of the P-plane waveguide layer; Furthermore, the etching depth of the left super-slave waveguide or the right super-slave waveguide is 1 to 1.2 μm.

8. The double-absorption loss type high-power single-mode semiconductor laser according to any one of claims 1 to 3, characterized in that: The cone angle of the tapered gain waveguide should be less than or equal to the fundamental mode diffraction angle, and the fundamental mode diffraction angle is given by θ=λ[2tan -1 (b / (1-b)) 1 / 2 ] / n eff- wget; Where w is the width of the main oscillation waveguide, n eff-n is the equivalent refractive index when the width of the main oscillation waveguide approaches infinity, n eff is the equivalent refractive index of the main oscillation waveguide, n3 is the bulk refractive index of the P-plane waveguide layer; Furthermore, the tapered gain waveguide has a taper angle of 3.8-4.2° and an etching depth of 0.5-1 μm.

9. The double-absorption loss type high-power single-mode semiconductor laser according to any one of claims 1 to 3, characterized in that: The dimensions of the absorption waveguide are: length 100-150 μm, width 10-20 μm, and a non-injection area of ​​2-5 μm is left in the middle; Furthermore, the absorption waveguide is selected to be H + Ion implantation, the implantation energy is 320keV, the implantation dose is 8×10 14 / cm -2 .

10. A method for preparing a double-absorption loss type high-power single-mode semiconductor laser according to any one of claims 1 to 9, characterized in that: include: Selecting a substrate; The epitaxial growth is performed by using a metal organic compound vapor deposition technology, and an N-side limiting layer, an N-side waveguide layer, an active region, a P-side waveguide layer, a P-side limiting layer and a P-side ohmic contact layer are sequentially grown from bottom to top on the surface of the substrate to form an epitaxial structure; Using ultraviolet exposure technology and inductively coupled plasma dry etching technology, the main oscillation waveguide, left super companion waveguide and right super companion waveguide are deeply etched on the epitaxial structure; Using ultraviolet exposure technology and inductively coupled plasma dry etching technology, a tapered gain waveguide is shallowly etched on the epitaxial structure; Using ion implantation technology, H is implanted into the epitaxial structure. + ions, forming an absorption waveguide; Using plasma enhanced vapor chemical deposition technology, an insulating layer is deposited on the epitaxial structure; Using photolithography technology, the P-surface electrode windows of the main oscillator waveguide and the tapered gain waveguide are etched; The magnetron sputtering technology is used to sputter the P-side electrode on the epitaxial structure; Thinning and polishing substrate; sputtering an N-side electrode on the back side of the substrate using a magnetron sputtering technique; The formed double-absorption loss type high-power single-mode semiconductor laser is cleaved, wire-bonded and packaged.

Images