Semiconductor laser chip

Abstract

The utility model relates to the technical field of semiconductor photoelectric devices, in particular to a semiconductor laser chip, which comprises a substrate and an epitaxial layer, the section of the epitaxial layer along the laser emitting direction is a first end face, the section of the epitaxial layer opposite to the laser emitting direction is a second end face, the first end face is provided with an antireflection film layer, and the second end face is provided with a second antireflection film layer. The second end face is provided with a high-reflection film layer, and the reflectivity of the antireflection film layer is smaller than that of the high-reflection film layer; the refractive index of the epitaxial layer is greater than or equal to that of the antireflection film layer; the refractive index of the epitaxial layer is larger than or equal to that of the high-reflection film layer. According to the utility model, by designing the refractive index and the reflectivity of the antireflection film layer and the high-reflection film layer, the laser modulus of the optical waveguide layer is reduced, stimulated radiation is accelerated to exceed spontaneous radiation, the threshold current density of the laser is reduced, and the slope efficiency is improved; meanwhile, light field distribution of the optical waveguide is optimized, and light absorption loss and waveguide loss are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor optoelectronic devices, in particular to a semiconductor laser chip. Background Art

[0002] Lasers are widely used in laser display, laser TV, laser projector, communication, medical treatment, weapons, guidance, ranging, spectral analysis, cutting, precision welding, high-density optical storage and other fields. There are many types of lasers, and the classification methods are also diverse, mainly including solid, gas, liquid, semiconductor and dye types of lasers; compared with other types of lasers, all-solid-state semiconductor ultraviolet lasers have the advantages of small size, high efficiency, light weight, good stability, long life, simple and compact structure, and miniaturization.

[0003] There are significant differences between lasers and nitride semiconductor light-emitting diodes.

[0004] 1) Laser is generated by stimulated radiation of carriers, the spectrum half-width is small, the brightness is very high, and the output power of a single laser can be in the W level, while nitride semiconductor light-emitting diodes are spontaneously radiated, and the output power of a single light-emitting diode is in the mW level;

[0005] 2) The current density of the laser is up to KA / cm 2 , which is more than 2 orders of magnitude higher than that of nitride light-emitting diodes, resulting in stronger electron leakage, more serious Auger recombination, stronger polarization effect, more serious electron-hole mismatch, and more serious efficiency attenuation Droop effect;

[0006] 3) The spontaneous transition radiation of the light-emitting diode is incoherent light that transitions from a high energy level to a low energy level without any external influence, while the laser is stimulated transition radiation, and the energy of the induced photon should be equal to the difference in the energy level of the electron transition, producing the same coherent light as the photon and the induced photon;

[0007] 4) Different principles: When an external voltage is applied to a light-emitting diode, electron holes jump to the active layer or pn junction to produce radiative recombination light, while a laser can only emit when the lasing conditions are met. The carrier distribution in the active region must be reversed, and the stimulated radiation light oscillates back and forth in the resonant cavity. The propagation in the gain medium amplifies the light, and the threshold condition is met so that the gain is greater than the loss, and finally the laser is output.

[0008] Nitride semiconductor ultraviolet lasers have the following problems: the lateral and transverse guidance mechanism and mode control of light waves are complex, which limits the improvement of beam quality. Ridge waveguide etching, resonant cavity cleavage, cavity surface coating and other process technologies are difficult, resulting in serious waveguide loss and resonant cavity light absorption loss. Utility Model Content

[0009] The utility model provides a semiconductor laser chip. By designing the refractive index and reflectivity of an anti-reflection and anti-reflection film layer and a high-reflection film layer, the laser mode number of an optical waveguide layer is reduced, stimulated radiation exceeds spontaneous radiation, the threshold current density of the laser is reduced, and the slope efficiency is improved.

[0010] The utility model provides a semiconductor laser chip, comprising a substrate and an epitaxial layer, wherein the cross section of the epitaxial layer along the laser emitting direction is a first end face, and the cross section of the epitaxial layer opposite to the laser emitting direction is a second end face, the first end face is provided with an anti-reflection and anti-reflection film layer, the second end face is provided with a high-reflection film layer, the reflectivity of the anti-reflection and anti-reflection film layer is lower than that of the high-reflection film layer; the refractive index of the epitaxial layer is greater than or equal to the refractive index of the anti-reflection and anti-reflection film layer; the refractive index of the epitaxial layer is greater than or equal to the refractive index of the high-reflection film layer.

[0011] Preferably, the high-reflection film layer and the anti-reflection and anti-reflection film layer form an optical resonant cavity; the reflectivity of the high-reflection film layer is 85-100%; the reflectivity of the anti-reflection and anti-reflection film layer is 10-95%; the refractive index of the epitaxial layer is 2-5, the refractive index of the anti-reflection and anti-reflection film layer is 1-3, and the refractive index of the high-reflection film layer is 1-3.

[0012] Preferably, the anti-reflection and anti-reflection film layer includes a first connecting layer, a first DBR periodic structure, and a first termination layer; and the high-reflection film layer includes a second connecting layer, a second DBR periodic structure, and a second termination layer.

[0013] Preferably, the first connection layer comprises Al2O3, Al2O3 / Ta2O5, Al2O3 / SiN z , Al2O3 / SiO2, Al2O3 / Nb2O5, Al2O3 / TiO2, AlON, AlON / SiN z , AlON / SiO2, AlON / Nb2O5, AlON / TiO2, AlON / Ta2O5, HfO2, TiO2, Ti2O3, Ti3O5, TiO, ZrO2, Nb2O5, Y2O3, CeO2, Ta2O5, SiO2, SiN z Any one or any combination thereof, wherein Z≥1; the first DBR periodic structure comprises (Ta2O5 / Al2O3) m 、(SiN z / SiO2) m 、(SiO2 / TiO2) m 、(Nb2O5 / SiO2) m 、(Ta2O5 / SiO2) m 、(Al2O3 / Ta2O5) m 、(SiO2 / SiN z )m 、(TiO2 / SiO2) m 、(SiO2 / Nb2O5) m 、(SiO2 / Ta2O5) m (Nb2O5 / Ta2O5) m 、(Ta2O5 / Nb2O5) m 、(Ta2O5 / TiO2) m 、(Nb2O5 / TiO2) m 、(TiO2 / Ta2O5) m 、(TiO2 / Nb2O5) m Any one or any combination of the following, wherein the DBR period number m: 20 ≥ m ≥ 1; the first termination layer comprises Ta2O5, AlON, Al2O3, SiO2, SiN z 、AlON / SiN z 、Al2O3 / Ta2O5、Al2O3 / SiN z , any one or any combination of Al2O3 / SiO2, Al2O3 / Nb2O5, Al2O3 / TiO2, AlON / SiO2, AlON / Nb2O5, AlON / TiO2, AlON / Ta2O5, HfO2, TiO2, Ti2O3, Ti3O5, TiO, ZrO2, Nb2O5, Y2O3, CeO2, where Z ≥ 1.

[0014] Preferably, the second connection layer comprises Al2O3, Al2O3 / Ta2O5, Al2O3 / SiN z , Al2O3 / SiO2, Al2O3 / Nb2O5, Al2O3 / TiO2, AlON, AlON / SiN z , AlON / SiO2, AlON / Nb2O5, AlON / TiO2, AlON / Ta2O5, HfO2, TiO2, Ti2O3, Ti3O5, TiO, ZrO2, Nb2O5, Y2O3, CeO2, Ta2O5, SiO2, SiN z Any one or any combination thereof, wherein Z≥1; the second DBR periodic structure comprises (Ta2O5 / Al2O3) n 、(SiN z / SiO2) n 、(SiO2 / TiO2) n 、(Nb2O5 / SiO2) n 、(Ta2O5 / SiO2) n 、(Al2O3 / Ta2O5) n 、(SiO2 / SiN z )n 、(TiO2 / SiO2) m 、(SiO2 / Nb2O5) n 、(SiO2 / Ta2O5) n 、(Nb2O5 / Ta2O5) n 、(Ta2O5 / Nb2O5) n 、(Ta2O5 / TiO2) n 、(Nb2O5 / TiO2) n 、(TiO2 / Ta2O5) n 、(TiO2 / Nb2O5) n Any one or any combination thereof, wherein the DBR period number n: 40 ≥ n ≥ 1; the second termination layer comprises Ta2O5, AlON, Al2O3, SiO2, SiN z 、AlON / SiN z 、Al2O3 / Ta2O5、Al2O3 / SiN z , Al2O3 / SiO2, Al2O3 / Nb2O5, Al2O3 / TiO2, AlON / SiO2, AlON / Nb2O5, AlON / TiO2, AlON / Ta2O5, HfO2, TiO2, Ti2O3, Ti3O5, TiO, ZrO2, Nb2O5, Y2O3, CeO2, any one or any combination, where Z≥1; and the number of periods of the second DBR periodic structure is greater than or equal to the number of periods of the first DBR periodic structure.

[0015] Preferably, the first connection layer is Al2O3, and the first DBR periodic structure is (Ta2O5 / Al2O3) m , the first termination layer is Ta2O5; the second connection layer is Al2O3, and the second DBR periodic structure is (Ta2O5 / Al2O3) n , the second termination layer is Ta2O5; the refractive index of the first connecting layer ≤ the refractive index of the second connecting layer ≤ the refractive index of the first termination layer ≤ the refractive index of the second termination layer ≤ the refractive index of the epitaxial layer; the density of the epitaxial layer ≤ the density of the first connecting layer ≤ the density of the second connecting layer ≤ the density of the first termination layer ≤ the density of the second termination layer; the lattice constant of the epitaxial layer ≤ the lattice constant of the first connecting layer ≤ the lattice constant of the second connecting layer ≤ the lattice constant of the first termination layer ≤ the lattice constant of the second termination layer.

[0016] Preferably, the first connection layer is AlON, and the first DBR periodic structure is (SiN z / SiO2) m , the first termination layer is AlON; the second connection layer is AlON / SiN z, the second DBR periodic structure is (SiO2 / TiO2) n , the second termination layer is SiO2; the refractive index of the second termination layer ≤ the refractive index of the second connection layer ≤ the refractive index of the first connection layer ≤ the refractive index of the first termination layer ≤ the refractive index of the epitaxial layer; the density of the second termination layer ≤ the density of the second connection layer ≤ the density of the first termination layer ≤ the density of the first connection layer ≤ the density of the epitaxial layer; the lattice constant of the second connection layer ≤ the lattice constant of the first termination layer ≤ the lattice constant of the first connection layer ≤ the lattice constant of the epitaxial layer ≤ the lattice constant of the second termination layer.

[0017] Preferably, the first connection layer is AlON / SiN z , the first DBR periodic structure is (SiO2 / TiO2) m , the first termination layer is SiO2; the refractive index of the first DBR periodic structure is ≤ the refractive index of the first connection layer ≤ the refractive index of the epitaxial layer ≤ the refractive index of the first termination layer;

[0018] Or the first connection layer is AlON, and the first DBR periodic structure is (SiN z / SiO2) m , the first termination layer is AlON / SiN z ; The refractive index of the first DBR periodic structure is ≤ the refractive index of the first termination layer ≤ the refractive index of the first connection layer ≤ the refractive index of the epitaxial layer;

[0019] Or the first connection layer is AlON, and the first DBR periodic structure is (SiN z / SiO2) m , the first termination layer (102c) is AlON; the refractive index of the first DBR periodic structure is ≤ the refractive index of the first termination layer ≤ the refractive index of the first connection layer ≤ the refractive index of the epitaxial layer;

[0020] Or the first connecting layer is AlON, and the first DBR periodic structure is (SiO2 / TiO2) m , the first termination layer is SiO2; the refractive index of the first termination layer ≤ the refractive index of the first DBR periodic structure ≤ the refractive index of the first connecting layer ≤ the refractive index of the epitaxial layer.

[0021] Preferably, the O element distribution of the first DBR periodic structure and the second DBR periodic structure has a function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / p*sin(p*x))(odd number of p≥1) curve distribution; the Al element distribution of the first DBR periodic structure and the second DBR periodic structure has a function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / q*sin(q*x))(odd number of q≥1) curve distribution; the Ta element distribution of the first DBR periodic structure and the second DBR periodic structure has a function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / r*sin(r*x))(odd number of r≥1) curve distribution. The Si element distribution of the first DBR periodic structure and the second DBR periodic structure has a curve distribution of function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / s*sin(s*x))(an odd number where s≥1); the N element distribution of the first DBR periodic structure and the second DBR periodic structure has a curve distribution of function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / t*sin(t*x))(an odd number where t≥1); the Ti element distribution of the first DBR periodic structure and the second DBR periodic structure has a curve distribution of function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / u*sin(u*x))(an odd number where u≥1).

[0022] Preferably, the O element distribution of the first connecting layer has a function y=lnx / x curve distribution; the Al element distribution of the first connecting layer has a function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / v*sin(v*x))(v≥1 odd number) curve distribution; the O element distribution of the first termination layer has a function y=sinx / x 2 The third quadrant curve distribution; the Ta element distribution of the first termination layer has a function y = 4 / π (sinx + 1 / 3sin3x + 1 / 5sin5x + ... + 1 / w*sin(w*x)) (w ≥ 1 odd number) curve distribution; the O element distribution of the second connection layer has a function y = e x / x third quadrant curve distribution; the Al element distribution of the second connection layer has a function y=cscx fourth quadrant curve distribution; the O element distribution of the second termination layer has a function y=lnx / e x Curve distribution; the Ta element distribution of the second termination layer has a function y = Ax 2 +Bx+C(A<0) curve distribution.

[0023] Compared with the prior art, the semiconductor laser chip provided by the utility model has the following beneficial effects: the utility model reduces the laser mode number of the optical waveguide layer, improves the degeneracy of photons, accelerates the stimulated radiation to exceed the spontaneous radiation, reduces the threshold current density of the laser and improves the slope efficiency by designing the refractive index and reflectivity of the anti-reflection and anti-reflection film layer and the high-reflection film layer; at the same time, the element distribution of the anti-reflection and anti-reflection film layer and the high-reflection film layer is designed to optimize the light field distribution of the optical waveguide, reduce light absorption loss and waveguide loss, and regulate the lateral and transverse guidance and mode change of the light wave, thereby improving the beam quality factor and far-field FFP image quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of a semiconductor laser chip according to an embodiment of the utility model;

[0025] Figure 2 This is a schematic diagram of an EDX test spectrum of an anti-reflection and anti-reflection film layer of a semiconductor laser chip according to an embodiment of the utility model;

[0026] Figure 3 This is a schematic diagram of an EDX test spectrum of a high-reflection film layer of a semiconductor laser chip according to an embodiment of the utility model;

[0027] Figure 4 This is a schematic diagram of an EDX test spectrum of an anti-reflection and anti-reflection film layer of a semiconductor laser chip according to an embodiment of the utility model;

[0028] Figure 5 This is a schematic diagram of an EDX test spectrum of a high-reflection film layer of a semiconductor laser chip according to an embodiment of the utility model;

[0029] Figure 6 This is a schematic diagram of an EDX test spectrum of an anti-reflection and anti-reflection film layer of a semiconductor laser chip according to an embodiment of the utility model;

[0030] Figure 7 This is a schematic diagram of an EDX test spectrum of an anti-reflection and anti-reflection film layer of a semiconductor laser chip according to an embodiment of the utility model;

[0031] Figure 8 This is a schematic diagram of an EDX test spectrum of an anti-reflection and anti-reflection film layer of a semiconductor laser chip according to an embodiment of the utility model;

[0032] Fig. 9 It is a schematic diagram of an EDX test spectrum of an anti-reflection and anti-reflection film layer of a semiconductor laser chip in an embodiment of the utility model.

[0033] Figure numerals: 100: substrate; 101: epitaxial layer; 102: anti-reflection and anti-reflection film layer; 103: high-reflection film layer; 102a: first connecting layer, 102b: first DBR periodic structure, 102c: first termination layer, 103a: second connecting layer, 103b: second DBR periodic structure, 103c: second termination layer. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0035] In order to solve the above problems, a semiconductor laser chip provided in an embodiment of the present application will be introduced and explained in detail through the following specific embodiments.

[0036] Reference Figure 1-9 The utility model provides a semiconductor laser chip, comprising a substrate 100 and an epitaxial layer 101, wherein a cross section of the epitaxial layer 101 along a laser emitting direction is a first end face, and a cross section of the epitaxial layer 101 opposite to the laser emitting direction is a second end face, an anti-reflection and anti-reflective film layer 102 (AR, Anti-Reflective) is provided on the first end face, and a high-reflective film layer 103 (HR, High-Reflective) is provided on the second end face, the reflectivity of the anti-reflection and anti-reflective film layer 102 is less than that of the high-reflective film layer 103; the refractive index of the epitaxial layer 101 is greater than or equal to the refractive index of the anti-reflection and anti-reflective film layer 102; the refractive index of the epitaxial layer 101 is greater than or equal to the refractive index of the high-reflective film layer 103.

[0037] The high-reflection film layer 103 and the anti-reflection and anti-reflection film layer 102 form an optical resonant cavity; the reflectivity of the high-reflection film layer 103 is 85-100%; the reflectivity of the anti-reflection and anti-reflection film layer 102 is 10-95%; the refractive index of the epitaxial layer 101 is 2-5, the refractive index of the anti-reflection and anti-reflection film layer 102 is 1-3, and the refractive index of the high-reflection film layer 103 is 1-3.

[0038] The anti-reflection and anti-reflection film layer 102 includes a first connection layer 102a, a first DBR periodic structure 102b, and a first termination layer 102c; the high-reflection film layer 103 includes a second connection layer 103a, a second DBR periodic structure 103b, and a second termination layer 103c; wherein DBR, Distributed Bragg Reflector, is a distributed Bragg reflector; the specific structure is as follows:

[0039] The first connection layer 102a includes Al2O3, Al2O3 / Ta2O5, Al2O3 / SiN z , Al2O3 / SiO2, Al2O3 / Nb2O5, Al2O3 / TiO2, AlON, AlON / SiN z , AlON / SiO2, AlON / Nb2O5, AlON / TiO2, AlON / Ta2O5, HfO2, TiO2, Ti2O3, Ti3O5, TiO, ZrO2, Nb2O5, Y2O3, CeO2, Ta2O5, SiO2, SiN z Any one or any combination of, where Z ≥ 1;

[0040] The first DBR periodic structure 102b includes (Ta2O5 / Al2O3) m 、(SiN z / SiO2) m 、(SiO2 / TiO2) m 、(Nb2O5 / SiO2) m 、(Ta2O5 / SiO2) m 、(Al2O3 / Ta2O5) m 、(SiO2 / SiN z ) m 、(TiO2 / SiO2) m 、(SiO2 / Nb2O5) m 、(SiO2 / Ta2O5) m (Nb2O5 / Ta2O5) m 、(Ta2O5 / Nb2O5) m 、(Ta2O5 / TiO2) m 、(Nb2O5 / TiO2) m 、(TiO2 / Ta2O5) m 、(TiO2 / Nb2O5) m Any one or any combination of, wherein the DBR period number m: 20 ≥ m ≥ 1;

[0041] The first termination layer 102c includes Ta2O5, AlON, Al2O3, SiO2, SiN z 、AlON / SiN z 、Al2O3 / Ta2O5、Al2O3 / SiN z, any one or any combination of Al2O3 / SiO2, Al2O3 / Nb2O5, Al2O3 / TiO2, AlON / SiO2, AlON / Nb2O5, AlON / TiO2, AlON / Ta2O5, HfO2, TiO2, Ti2O3, Ti3O5, TiO, ZrO2, Nb2O5, Y2O3, CeO2, where Z ≥ 1.

[0042] The second connection layer 103a includes Al2O3, Al2O3 / Ta2O5, Al2O3 / SiN z , Al2O3 / SiO2, Al2O3 / Nb2O5, Al2O3 / TiO2, AlON, AlON / SiN z , AlON / SiO2, AlON / Nb2O5, AlON / TiO2, AlON / Ta2O5, HfO2, TiO2, Ti2O3, Ti3O5, TiO, ZrO2, Nb2O5, Y2O3, CeO2, Ta2O5, SiO2, SiN z Any one or any combination of, where Z ≥ 1;

[0043] The second DBR periodic structure 103b includes (Ta2O5 / Al2O3) n 、(SiN z / SiO2) n 、(SiO2 / TiO2) n 、(Nb2O5 / SiO2) n 、(Ta2O5 / SiO2) n 、(Al2O3 / Ta2O5) n 、(SiO2 / SiN z ) n 、(TiO2 / SiO2) m 、(SiO2 / Nb2O5) n 、(SiO2 / Ta2O5) n 、(Nb2O5 / Ta2O5) n 、(Ta2O5 / Nb2O5) n 、(Ta2O5 / TiO2) n 、(Nb2O5 / TiO2) n 、(TiO2 / Ta2O5) n 、(TiO2 / Nb2O5) n Any one or any combination of, wherein the DBR period number n: 40 ≥ n ≥ 1;

[0044] The second termination layer 103c includes Ta2O5, AlON, Al2O3, SiO2, SiN z、AlON / SiN z 、Al2O3 / Ta2O5、Al2O3 / SiN z , Al2O3 / SiO2, Al2O3 / Nb2O5, Al2O3 / TiO2, AlON / SiO2, AlON / Nb2O5, AlON / TiO2, AlON / Ta2O5, HfO2, TiO2, Ti2O3, Ti3O5, TiO, ZrO2, Nb2O5, Y2O3, CeO2, any one or any combination, where Z≥1; and the number of periods of the second DBR periodic structure 103b is greater than or equal to the number of periods of the first DBR periodic structure 102b.

[0045] Furthermore, if Figure 2 , 3 As shown, the first connection layer 102a is Al2O3, and the first DBR periodic structure 102b is (Ta2O5 / Al2O3) m , the first termination layer (102c) is Ta2O5; the second connection layer 103a is Al2O3, and the second DBR periodic structure 103b is (Ta2O5 / Al2O3) n , the second termination layer 103c is Ta2O5; the refractive index of the first connection layer ≤ the refractive index of the second connection layer ≤ the refractive index of the first termination layer ≤ the refractive index of the second termination layer ≤ the refractive index of the epitaxial layer; the density of the epitaxial layer ≤ the density of the first connection layer ≤ the density of the second connection layer ≤ the density of the first termination layer ≤ the density of the second termination layer; the lattice constant of the epitaxial layer ≤ the lattice constant of the first connection layer ≤ the lattice constant of the second connection layer ≤ the lattice constant of the first termination layer ≤ the lattice constant of the second termination layer.

[0046] Furthermore, if Figure 4 , 5 As shown, the first connection layer 102a is AlON, and the first DBR periodic structure 102b is (SiN z / SiO2) m , the first termination layer 102c is AlON; the second connection layer 103a is AlON / SiN z , the second DBR periodic structure 103b is (SiO2 / TiO2) n , the second termination layer 103c is SiO2; the refractive index of the second termination layer ≤ the refractive index of the second connection layer ≤ the refractive index of the first connection layer ≤ the refractive index of the first termination layer ≤ the refractive index of the epitaxial layer; the density of the second termination layer ≤ the density of the second connection layer ≤ the density of the first termination layer ≤ the density of the first connection layer ≤ the density of the epitaxial layer; the lattice constant of the second connection layer ≤ the lattice constant of the first termination layer ≤ the lattice constant of the first connection layer ≤ the lattice constant of the epitaxial layer ≤ the lattice constant of the second termination layer.

[0047] Furthermore, if Figure 6 As shown, the first connection layer 102a is AlON / SiN z , the first DBR periodic structure 102b is (SiO2 / TiO2) m , the first termination layer 102c is SiO2; the refractive index of the first DBR periodic structure is ≤ the refractive index of the first connection layer ≤ the refractive index of the epitaxial layer ≤ the refractive index of the first termination layer;

[0048] or Figure 7 As shown, the first connection layer 102a is AlON, and the first DBR periodic structure 102b is (SiN z / SiO2) m , the first termination layer 102c is AlON / SiN z ; The refractive index of the first DBR periodic structure is ≤ the refractive index of the first termination layer ≤ the refractive index of the first connection layer ≤ the refractive index of the epitaxial layer;

[0049] or Figure 8 As shown, the first connection layer 102a is AlON, and the first DBR periodic structure 102b is (SiN z / SiO2) m , the first termination layer 102c is AlON; the refractive index of the first DBR periodic structure is ≤ the refractive index of the first termination layer ≤ the refractive index of the first connection layer ≤ the refractive index of the epitaxial layer;

[0050] or Fig. 9 As shown, the first connection layer 102a is AlON, and the first DBR periodic structure 102b is (SiO2 / TiO2) m , the first termination layer 102c is SiO2; the refractive index of the first termination layer ≤ the refractive index of the first DBR periodic structure ≤ the refractive index of the first connecting layer ≤ the refractive index of the epitaxial layer.

[0051] In the utility model, the O element distribution of the first DBR periodic structure 102b and the second DBR periodic structure 103b has a function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / p*sin(p*x))(p≥1 odd number) curve distribution; the Al element distribution of the first DBR periodic structure 102b and the second DBR periodic structure 103b has a function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / q*sin(q*x))(q≥1 odd number) curve distribution; the Ta element distribution of the first DBR periodic structure 102b and the second DBR periodic structure 103b has a function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / r*sin(r*x))(r≥1 odd number) curve distribution. Line distribution; the Si element distribution of the first DBR periodic structure 102b and the second DBR periodic structure 103b has a curve distribution of function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / s*sin(s*x))(s≥1 odd number); the N element distribution of the first DBR periodic structure 102b and the second DBR periodic structure 103b has a curve distribution of function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / t*sin(t*x))(t≥1 odd number); the Ti element distribution of the first DBR periodic structure 102b and the second DBR periodic structure 103b has a curve distribution of function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / u*sin(u*x))(u≥1 odd number).

[0052] In the present invention, the O element distribution of the first connection layer 102a has a function y=lnx / x curve distribution; the Al element distribution of the first connection layer 102a has a function y=4 / π(sinx+1 / 3sin3x+1 / 5sin5x+…+1 / v*sin(v*x))(v≥1 odd number) curve distribution; the O element distribution of the first termination layer 102c has a function y=sinx / x 2 The third quadrant curve distribution; the Ta element distribution of the first termination layer 102c has a function y = 4 / π (sinx + 1 / 3 sin3x + 1 / 5 sin5x + ... + 1 / w * sin (w * x)) (w ≥ 1 odd number) curve distribution; the O element distribution of the second connection layer 103a has a function y = e x / x third quadrant curve distribution; the Al element distribution of the second connection layer 103a has a function y=cscx fourth quadrant curve distribution; the O element distribution of the second termination layer 103c has a function y=lnx / e xCurve distribution; the Ta element distribution of the second termination layer 103c has a function y=Ax 2 +Bx+C(A<0) curve distribution.

[0053] In the utility model, the epitaxial layer 101 includes a lower confinement layer, an upper waveguide layer, a lower waveguide layer, an electron blocking layer, and an upper confinement layer. The epitaxial layer 101 is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond. The substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate, diamond, graphene, sapphire / SiN x , Sapphire / SiO2 / SiN x Any one of a composite substrate, a sapphire / SiNx / SiO2 composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

[0054] In a specific embodiment, the internal optical loss of the laser is reduced from 16.3 to 8.9, a decrease of about 83%; the laser beam quality factor M 2 The slope efficiency decreased from 21.89 to 1.14, a decrease of about 66%; the slope efficiency increased from 1.21 to 2.09, an increase of about 73%, and the threshold current density increased from 2.4 kA / cm 2 Down to 0.79 kA / cm 2 , a decrease of about 67%; as shown in the following table;

[0055]

[0056]

[0057] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A semiconductor laser chip, comprising a substrate (100) and an epitaxial layer (101), wherein a cross section of the epitaxial layer (101) along a laser emitting direction is a first end face, and a cross section of the epitaxial layer (101) opposite to the laser emitting direction is a second end face, characterized in that: The first end surface is provided with an anti-reflection and anti-reflection film layer (102), and the second end surface is provided with a high-reflection film layer (103); the reflectivity of the anti-reflection and anti-reflection film layer (102) is lower than that of the high-reflection film layer (103); the refractive index of the epitaxial layer (101) is greater than or equal to the refractive index of the anti-reflection and anti-reflection film layer (102); and the refractive index of the epitaxial layer (101) is greater than or equal to the refractive index of the high-reflection film layer (103).

2. A semiconductor laser chip according to claim 1, characterized in that: The high-reflection film layer (103) and the anti-reflection and anti-reflection film layer (102) form an optical resonant cavity; the reflectivity of the high-reflection film layer (103) is 85-100%; the reflectivity of the anti-reflection and anti-reflection film layer (102) is 10-95%; the refractive index of the epitaxial layer (101) is 2-5, the refractive index of the anti-reflection and anti-reflection film layer (102) is 1-3, and the refractive index of the high-reflection film layer (103) is 1-3.

3. A semiconductor laser chip according to claim 1, characterized in that: The anti-reflection and anti-reflection film layer (102) comprises a first connection layer (102a), a first DBR periodic structure (102b), and a first termination layer (102c); the high-reflection film layer (103) comprises a second connection layer (103a), a second DBR periodic structure (103b), and a second termination layer (103c).

4. A semiconductor laser chip according to claim 3, characterized in that: The first connection layer (102a) is Al2O3, and the first DBR periodic structure (102b) is (Ta2O5 / Al2O3) m , the first termination layer (102c) is Ta2O5; the second connection layer (103a) is Al2O3, and the second DBR periodic structure (103b) is (Ta2O5 / Al2O3) n , the second termination layer (103c) is Ta2O5; the refractive index of the first connecting layer ≤ the refractive index of the second connecting layer ≤ the refractive index of the first termination layer ≤ the refractive index of the second termination layer ≤ the refractive index of the epitaxial layer; the density of the epitaxial layer ≤ the density of the first connecting layer ≤ the density of the second connecting layer ≤ the density of the first termination layer ≤ the density of the second termination layer; the lattice constant of the epitaxial layer ≤ the lattice constant of the first connecting layer ≤ the lattice constant of the second connecting layer ≤ the lattice constant of the first termination layer ≤ the lattice constant of the second termination layer.

5. The semiconductor laser chip according to claim 4, characterized in that: The first connection layer (102a) is AlON, and the first DBR periodic structure (102b) is (SiN z / SiO2) m , the first termination layer (102c) is AlON; the second connection layer (103a) is AlON / SiN z , the second DBR periodic structure (103b) is (SiO2 / TiO2) n , the second termination layer (103c) is SiO2; the refractive index of the second termination layer ≤ the refractive index of the second connection layer ≤ the refractive index of the first connection layer ≤ the refractive index of the first termination layer ≤ the refractive index of the epitaxial layer; the density of the second termination layer ≤ the density of the second connection layer ≤ the density of the first termination layer ≤ the density of the first connection layer ≤ the density of the epitaxial layer; the lattice constant of the second connection layer ≤ the lattice constant of the first termination layer ≤ the lattice constant of the first connection layer ≤ the lattice constant of the epitaxial layer ≤ the lattice constant of the second termination layer.

6. The semiconductor laser chip according to claim 5, characterized in that: The first connection layer (102a) is AlON / SiN z , the first DBR periodic structure (102b) is (SiO2 / TiO2) m , the first termination layer (102c) is SiO2; the refractive index of the first DBR periodic structure is ≤ the refractive index of the first connection layer ≤ the refractive index of the epitaxial layer ≤ the refractive index of the first termination layer; Or the first connection layer (102a) is AlON, and the first DBR periodic structure (102b) is (SiN z / SiO2) m The first termination layer (102c) is AlON / SiN z ; The refractive index of the first DBR periodic structure is ≤ the refractive index of the first termination layer ≤ the refractive index of the first connection layer ≤ the refractive index of the epitaxial layer; Or the first connection layer (102a) is AlON, and the first DBR periodic structure (102b) is (SiN z / SiO2) m , the first termination layer (102c) is AlON; the refractive index of the first DBR periodic structure is ≤ the refractive index of the first termination layer ≤ the refractive index of the first connection layer ≤ the refractive index of the epitaxial layer; Or the first connection layer (102a) is AlON, and the first DBR periodic structure (102b) is (SiO2 / TiO2) m , the first termination layer (102c) is SiO2; the refractive index of the first termination layer ≤ the refractive index of the first DBR periodic structure ≤ the refractive index of the first connection layer ≤ the refractive index of the epitaxial layer.

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