Laser chip capable of inhibiting in-plane amplified spontaneous emission

Abstract

According to the laser chip capable of inhibiting in-plane amplified spontaneous emission, the first inclined edge and the second inclined edge are designed, opposite edges parallel to the first cleavage edge and the second cleavage edge respectively are damaged, a first parasitic cavity and a second parasitic cavity existing in a natural cleavage laser chip are eliminated, and the laser chip can inhibit in-plane amplified spontaneous emission. Therefore, the formation of in-plane amplified spontaneous emission of the laser chip is remarkably inhibited, meaningless consumption of carriers in a laser emission layer in the laser chip is prevented, the luminous efficiency of the laser chip on laser wavelength can be improved, the light-light conversion efficiency of the laser from pump light to emission laser is improved, and the output power of the laser is finally improved. And secondly, due to the suppression of amplified spontaneous radiation in a laser chip plane and the improvement of the light-light conversion efficiency of the laser, the power consumption of the laser can be obviously reduced under the condition of certain output power, the operation cost of the laser is reduced to a certain extent, and the cost performance of the laser is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser chips, and particularly to a laser chip capable of suppressing in-plane amplified spontaneous emission. Background Art

[0002] The optically pumped external cavity surface-emitting semiconductor laser adopts a gain chip structure in the form of a thin sheet, and then uses external optical elements to realize the laser resonator or other optical functions. Therefore, it combines the advantages of high power and high beam quality of solid disk lasers, as well as the flexibility of the emission wavelength of semiconductor lasers that can be designed, and can output high power of dozens of watts and good beam quality close to the diffraction limit. At the same time, the external cavity structure of the optically pumped external cavity surface-emitting semiconductor laser enables it to easily perform functions such as laser nonlinear frequency conversion, laser mode locking, wavelength tuning, etc., and has extremely important applications in laser display, laser processing, laser spectroscopy, medical and health, quantum technology, etc.

[0003] However, the output power of the external cavity surface-emitting semiconductor laser is directly related to the luminous efficiency of the laser chip. Only a high-efficiency laser chip can support high-power laser output. In the laser chips of previous external cavity surface-emitting semiconductor lasers, since the laser chips are naturally cleaved, the four cleavage edges of the chips are neat and smooth, and its two opposite edges will form a parasitic plane-plane laser resonator.

[0004] However, although the light output direction of the laser is perpendicular to the surface of the chip, the spontaneous emission generated in the epitaxial plane of the chip will be amplified by the above-mentioned parasitic cavity (parasitic plane-plane laser resonator) to form amplified spontaneous emission. The amplified spontaneous emission is a completely unnecessary loss for the laser. It consumes the carriers in the chip but makes no contribution to the output laser, thus actually reducing the luminous efficiency of the laser chip and reducing the output power of the laser. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the present invention provides a laser chip capable of suppressing in-plane amplified spontaneous emission to solve the technical problem that the spontaneous emission generated in the epitaxial plane of the chip in the prior art consumes the carriers in the chip but makes no contribution to the output laser, thus actually reducing the luminous efficiency of the laser chip and reducing the output power of the laser.

[0006] The present invention provides a laser chip capable of suppressing in-plane amplified spontaneous emission, including:

[0007] A chip substrate, an integrated multi-layer film high reflector, a pump absorption and laser emission region, a wide bandgap window layer, and an anti-oxidation protective layer connected in sequence;

[0008] Moreover, the two adjacent sides of the laser chip parallel to the light source are neat and smooth first cleavage edges and second cleavage edges, and the first cleavage edge and the second cleavage edge respectively correspond to adjacent first grinding edges and second grinding edges. The first grinding edge and the second grinding edge are ground off to respectively form a first inclined edge and a second inclined edge having an included angle with the first grinding edge and the second grinding edge.

[0009] Optionally, the chip substrate includes:

[0010] It is made of semiconductor or compound semiconductor material, and the lattice constant of the chip substrate matches the lattice constants of the materials used in the integrated multi-layer film high reflector, pump absorption and laser emission region, wide bandgap window layer, and anti-oxidation protection layer.

[0011] Optionally, the integrated multi-layer film high reflector includes:

[0012] It is composed of alternating high refractive index material layers and low refractive index material layers. The optical thickness of each high refractive index material layer and low refractive index material layer is equal to one-fourth of the laser wavelength emitted by the laser chip, and both the high refractive index material layer and the low refractive index material layer are made of semiconductor or compound semiconductor materials.

[0013] Optionally, the pump absorption and laser emission region includes:

[0014] It is composed of alternating pump absorption layers and laser emission layers. The sum of the thicknesses of each pump absorption layer and laser emission layer is equal to one-half of the laser wavelength emitted by the laser chip, and both the pump absorption layer and the laser emission layer are made of semiconductor or compound semiconductor materials.

[0015] Optionally, the wide bandgap window layer includes:

[0016] The potential barrier of the pump absorption layer is higher than that of the laser emission layer, and the potential barriers of the wide bandgap window layer are all higher than those of the pump absorption layer and the laser emission layer.

[0017] Optionally, the anti-oxidation protection layer includes:

[0018] It is made of semiconductor or compound semiconductor material.

[0019] Optionally, the included angle includes:

[0020] Its degree range is taken as 2° - 10°.

[0021] The present invention compared with the prior art:

[0022] First, the first inclined side and the second inclined side of the present invention damage the opposite sides parallel to the first cleavage side and the second cleavage side respectively, eliminating the first parasitic cavity and the second parasitic cavity existing in the natural cleavage laser chip, thereby significantly suppressing the formation of in-plane amplified spontaneous emission in the laser chip, preventing the unnecessary consumption of carriers in the laser emission layer of the laser chip, improving the luminous efficiency of the laser chip at the laser wavelength, enhancing the light-light conversion efficiency of the laser from the pump light to the emitted laser, and ultimately increasing the output power of the laser. Secondly, due to the suppression of the in-plane amplified spontaneous emission of the laser chip and the improvement of the light-light conversion efficiency of the laser, the power consumption of the laser can be significantly reduced under the condition of a certain output power, reducing the operating cost of the laser to a certain extent and improving the cost performance of the laser. Thirdly, the increase in the output power of the laser brought about by the suppression of the in-plane amplified spontaneous emission of the laser chip enables the laser to be applicable to more application scenarios that require high output power, effectively expanding the application value of the laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings herein are incorporated into the specification and form a part of this specification, showing embodiments in accordance with the present invention and, together with the specification, are used to explain the principles of the present invention.

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is a schematic structural diagram of the laser chip in the present invention;

[0026] Figure 2 It is the measured amplified spontaneous emission diagram in the present invention;

[0027] Figure 3 It is a schematic diagram of the principle of an external cavity surface emitting laser composed of the laser chip in an embodiment of the present invention.

[0028] DESCRIPTION OF THE REFERENCE NUMERALS

[0029] 1. Chip substrate; 2. Integrated multi-layer film high reflector; 3. Pump absorption and laser emission region; 4. Wide-bandgap window layer; 5. Anti-oxidation protection layer; 6. First cleavage edge; 7. Second cleavage edge; 8. First grinding edge; 9. Second grinding edge; 10. First inclined edge; 11. Second inclined edge; 12. Ground portion; 13. High refractive index material layer; 14. Low refractive index material layer; 15. Pump absorption layer; 16. Laser emission layer; 17. First parasitic cavity; 18. Second parasitic cavity; 19. Laser chip; 20. Heat transfer medium; 21. Heat dissipation device; 22. Pump beam; 23. Intra-cavity optical element; 24. Laser coupling output element; 25. Output laser beam. Detailed implementation manners

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, rather than all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application. In the embodiments of the present invention, functional units with the same reference numerals have the same and similar structures and functions.

[0031] See Figure 1 , a laser chip 19 capable of suppressing in-plane amplified spontaneous emission, comprising:

[0032] A chip substrate 1, an integrated multi-layer film high reflector 2, a pump absorption and laser emission region 3, a wide-bandgap window layer 4, and an anti-oxidation protection layer 5 connected in sequence;

[0033] Moreover, the two adjacent sides of the laser chip 19 parallel to the light source are a neat and smooth first cleavage edge 6 and a second cleavage edge 7. The first cleavage edge 6 and the second cleavage edge 7 respectively correspond to an adjacent first grinding edge 8 and a second grinding edge 9. The first grinding edge 8 and the second grinding edge 9 are ground off to respectively form a first inclined edge 10 and a second inclined edge 11 having an included angle with the first grinding edge 8 and the second grinding edge 9.

[0034] In this embodiment, the laser chip 19 obtained by natural cleavage has neat and smooth first cleavage edge 6 and second cleavage edge 7. Their opposite sides are the first grinding edge 8 and the second grinding edge 9 respectively, and both are also neat and smooth. Therefore, the first cleavage edge 6 and the first grinding edge 8 will form the first parasitic cavity 17. Similarly, the second cleavage edge 7 and the second grinding edge 9 will also form the second parasitic cavity 18. When the first grinding edge 8 and the second grinding edge 9 are ground off, that is, they each become non-parallel to the first cleavage edge 6 and the second cleavage edge 7, but have a certain angle with the first cleavage edge 6 and the second cleavage edge 7 respectively, forming the first inclined edge 10 and the second inclined edge 11. In this case, the first parasitic cavity 17 and the second parasitic cavity 18 in the laser chip 19 will no longer exist.

[0035] When an external pump light source is provided and an appropriate external optical mirror is provided, the pump absorption layer 15 in the pump absorption and laser emission region 3 in the laser chip 19 can absorb the photon energy of the pump light source to generate photo-generated carriers. The photo-generated carriers generated in the pump absorption layer 15 diffuse and are then captured by the laser emission layer 16, generating radiative transitions in the laser emission layer 16. This radiative transition resonates in the laser resonator formed by the external optical mirror and the integrated multi-layer film high reflector 2 in the laser chip 19, generating stimulated emission and being amplified, and finally forming laser output in the direction perpendicular to the surface of the laser chip 19.

[0036] See Figure 2 and Figure 3 As shown, during the laser generation process, if there are the first parasitic cavity 17 and the second parasitic cavity 18 inside the laser chip 19, amplified spontaneous emission will occur therein. Then the photo-generated carriers in the laser emission layer 16 will be consumed to a certain extent, thereby reducing the luminous efficiency of the laser chip 19. In the present invention, by grinding off the first grinding edge 8 and the second grinding edge 9 to form the first inclined edge 10 and the second inclined edge 11, the first parasitic cavity 17 and the second parasitic cavity 18 can be eliminated, the amplified spontaneous emission in the laser chip 19 can be suppressed, the unnecessary consumption of carriers in the laser emission layer 16 can be reduced, and the luminous efficiency of the laser chip 19 and the output power of the laser can be improved.

[0037] Among them, the pump absorption and laser emission region 3 can absorb the energy of the external pump light and generate radiative transitions; this radiative transition forms stimulated emission optical amplification in the resonator formed by the integrated multi-layer film high reflector 2 and the external laser reflector, and outputs laser. The first inclined edge 10 and the second inclined edge 11 in the chip ensure that there is no parasitic cavity in the chip that can amplify spontaneous emission, so the in-plane amplified spontaneous emission of the chip can be suppressed, the luminous efficiency of the chip can be significantly improved, thereby improving the optical-optical conversion efficiency of the laser, and finally enhancing the output power of the laser.

[0038] In another embodiment, the chip substrate 1 includes:

[0039] It is made of semiconductor or compound semiconductor material, and the lattice constant of the chip substrate 1 matches the lattice constants of the materials used in the integrated multi-layer film high reflector 2, the pump absorption and laser emission region 3, the wide bandgap window layer 4, and the anti-oxidation protection layer 5.

[0040] The lattice constant of the chip substrate 1 is substantially matched with the lattice constants of the materials used in each part of the integrated multi-layer film high reflector 2, the pump absorption and laser emission region 3, the wide bandgap window layer 4, the anti-oxidation protection layer 5, etc. on the chip. If the above matching is out of tune, other material layers for compensating the out-of-tune can be added to the chip.

[0041] In another embodiment, the integrated multi-layer film high reflector 2 includes:

[0042] It is composed of alternating high refractive index material layers 13 and low refractive index material layers 14. The optical thickness of each high refractive index material layer 13 and low refractive index material layer 14 is equal to one quarter of the laser wavelength emitted by the laser chip 19, and both the high refractive index material layers 13 and low refractive index material layers 14 are made of semiconductor or compound semiconductor materials.

[0043] The integrated multi-layer film high reflector 2 has a high reflectivity for the laser wavelength and is composed of several pairs of high refractive index material layers 13 and low refractive index material layers 14. The optical thickness of each high refractive index material layer 13 and low refractive index material layer 14 is equal to one quarter of the laser wavelength. The material used for each layer is a semiconductor or compound semiconductor material, and the lattice constant of the material is substantially matched with the lattice constant of the material of the chip substrate 1 layer.

[0044] In another embodiment, the pump absorption and laser emission region 3 includes:

[0045] It is composed of alternating pump absorption layers 15 and laser emission layers 16. The sum of the thicknesses of each pump absorption layer 15 and laser emission layer 16 is equal to one half of the laser wavelength emitted by the laser chip 19, and both the pump absorption layers 15 and laser emission layers 16 are made of semiconductor or compound semiconductor materials.

[0046] The pump absorption and laser emission region 3 is composed of pump absorption layers 15 and laser emission layers 16, which are both semiconductor or compound semiconductor materials, and the lattice constant is substantially matched with the lattice constant of the material of the chip substrate 1. The sum of the thicknesses of the pump absorption layer 15 and the laser emission layer 16 is equal to one half of the laser wavelength.

[0047] In another embodiment, the wide bandgap window layer 4 includes:

[0048] The barrier of the pump absorption layer 15 is higher than that of the laser emission layer 16, and the barriers of the wide-bandgap window layer 4 are all higher than those of the pump absorption layer 15 and the laser emission layer 16.

[0049] Among them, the barrier of the pump absorption layer 15 is relatively high, and the barrier of the laser emission layer 16 is relatively low. The pump absorption layer 15 can absorb the light energy emitted by an external pump light source to generate photo-generated carriers; these photo-generated carriers diffuse into the laser emission layer 16 with a lower barrier and emit radiative transitions. The thickness of the laser emission layer 16 is on the order of several nanometers and has quantum effects. The material barrier of the wide-bandgap window layer 4 is higher than the material barriers of the pump absorption layer 15 and the laser emission layer 16 in the pump absorption and laser emission region 3, and can prevent the photo-generated carriers generated in the pump absorption layer 15 from diffusing to the surface of the chip to generate non-radiative recombination. The wide-bandgap window layer 4 is transparent to the light emitted by the external excitation light source and also transparent to the laser wavelength.

[0050] In another embodiment, the anti-oxidation protection layer 5 includes:

[0051] It is made of semiconductor or compound semiconductor materials.

[0052] The anti-oxidation protection layer 5 is made of semiconductor or compound semiconductor materials, and this material will not be oxidized even when exposed to air, and plays a protective role for each layer material in the chip. At the same time, the anti-oxidation protection layer 5 is also transparent to the laser wavelength.

[0053] In another embodiment, the included angle includes:

[0054] Its degree range is taken as 2° - 10°, and preferably 5°.

[0055] The working principle of the present invention is:

[0056] See Figure 1 and Figure 3, when an external pump light is incident on the laser chip 19, the bandgap energy of the pump absorption layer 15 material in the pump absorption and laser emission region 3 in the laser chip 19 is slightly smaller than the photon energy of the used external incident pump light. Therefore, it can absorb the energy of the photons emitted by the external pump light source. After the pump absorption layer 15 absorbs the energy of the external pump light, photo-generated carriers are generated therein. Since the material barrier of the pump absorption layer 15 is higher than that of the laser emission layer 16, the photo-generated carriers generated in the pump absorption layer 15 will diffuse into the laser reflection layer through diffusion and be confined therein to emit radiative transitions. When a suitable external laser mirror is added to form a resonant cavity with the integrated multi-layer high-reflection mirror 2 in the laser chip 19, the radiative transitions in the laser emission layer 16 resonate in the laser resonant cavity, generating stimulated emission and being amplified, that is, the amplification of stimulated emission of light, to form laser output. The central wavelength of the radiative transitions generated in the laser reflection layer is the laser wavelength. The bandgap energy of the material used for the wide-bandgap window layer 4 in the laser chip 19 is higher than that of the pump absorption layer 15 and the laser emission layer 16 in the pump absorption and laser emission region 3. Therefore, it can prevent the photo-generated carriers generated in the pump absorption layer 15 from diffusing to the surface of the laser chip 19 to generate non-radiative recombination. The outermost anti-oxidation protection layer 5 of the chip can protect all the epitaxial layers in the chip from being oxidized in the air.

[0057] If the laser chip 19 has a rectangular shape obtained by ordinary natural cleavage, its four cleavage edges, including the first cleavage edge 6 and the second cleavage edge 7, are flat and smooth, similar to a plane mirror. Therefore, the first cleavage edge 6 and the first ground edge 8 opposite to it will form a parasitic laser resonant cavity, that is, the first parasitic cavity 17. Similarly, the second cleavage edge 7 and the second ground edge 9 opposite to it will also form a parasitic laser resonant cavity, that is, the second parasitic cavity 18.

[0058] After the chip is pumped by an external pump light source, a large number of photo-generated carriers will accumulate in the laser emission layer 16. Even if there is an external laser resonant cavity, most of the above-mentioned photo-generated carriers undergo stimulated emission in the direction of laser oscillation, that is, the direction perpendicular to the surface of the laser chip 19, to form laser output. However, there are still a considerable number of carriers that will oscillate in the first parasitic cavity 17 and the second parasitic cavity 18. The direction of this oscillation is parallel to the surface of the laser chip 19. Although they do not reach the laser oscillation threshold and cannot form laser, they will form the amplification of spontaneous emission, that is, amplified spontaneous emission. This amplified spontaneous emission will obviously consume the photo-generated carriers in the laser emission layer 16 in the laser chip 19, thereby reducing the luminous efficiency of the laser chip 19 at the laser wavelength, further reducing the light-light conversion efficiency of the laser from the pump laser to the output laser, and finally reducing the output power of the laser.

[0059] In the present invention, by grinding off the opposite sides of the first cleavage edge 6 and the second cleavage edge 7 of the laser chip 19, namely the first grinding edge 8 and the second grinding edge 9, a first inclined edge 10 having a certain angle with the first cleavage edge 6 and a second inclined edge 11 having a certain angle with the second cleavage edge 7 are formed, thereby eliminating the aforementioned first parasitic cavity 17 and second parasitic cavity 18, achieving the purpose of suppressing amplified spontaneous emission in the laser chip 19, improving the luminous efficiency of the laser chip 19, and enhancing the output power of the laser.

[0060] A specific embodiment is provided to illustrate the above technical solution:

[0061] See Figure 3 , the laser chip 19 is a laser chip 19 capable of suppressing in-plane amplified spontaneous emission in the present invention, with a size of 4 mm × 4 mm. The chip substrate 1 of the laser chip 19 is made of undoped GaAs material with a thickness of 350 μm. The integrated multi-layer high-reflection mirror 2 in the chip consists of 30 pairs of high refractive index material layers 13 and low refractive index material layers 14. The high refractive index material layer is Al0.1GaAs with a thickness of 72 nm; the low refractive index material layer 14 is AlAs with a thickness of 85 nm. The formed integrated multi-layer high-reflection mirror 2 has a high-reflection spectral bandwidth of 80 nm, the center wavelength of its reflection spectrum is 950 nm, and the reflectivity of the high-reflection part > 99.9%.

[0062] The pump absorption and laser emission region 33 in the laser chip 19 is composed of a pump absorption layer 15 and a laser emission layer 16. The pump absorption layer 15 is made of GaAs material, with a bandgap energy of 1.42 eV, which can absorb 808 nm pump laser. The thickness of the pump absorption layer 15 is 132 nm. The laser emission layer 16 is made of In0.11GaAs material, with a peak wavelength of 950 nm for the emitted fluorescence, and the thickness of the material layer is 8 nm.

[0063] The wide bandgap window layer 4 in the laser chip 19 is a high barrier material Al0.6GaAs with a thickness of 151 nm. The anti-oxidation protection layer 5 is made of GaAs material with a thickness of 10 nm. The first cleavage edge 6 and the second cleavage edge 7 are two adjacent edges of the chip, and the first grinding edge 8 and the second grinding edge 9 are the opposite sides of the first cleavage edge 6 and the second cleavage edge 7 respectively. The first grinding edge 8 and the second grinding edge 9 are both ground off by mechanical methods to form a first inclined edge 10 and a second inclined edge 11 respectively, and the angles between them and the first grinding edge 8 and the second grinding edge 9 are both 5°. The material of the ground part 12 is discarded. The first parasitic cavity 17 and the second parasitic cavity 18 are both eliminated by the above operations.

[0064] The heat transfer medium 20 is an epitaxially grown diamond block with high thermal conductivity, and the thermal conductivity > 1800 W·m -1·K-1, the size of the diamond block is 5mm × 5mm × 0.5mm. The heat dissipation device 21 is a thermoelectric cooling TEC module, and its temperature can be accurately controlled by an external controller. The pump beam 22 is a laser beam emitted by a semiconductor laser coupled out by an optical fiber, with a wavelength of 808nm, and passes through a collimating and focusing system, and finally focuses on the laser chip 19. The intracavity optical element 23 is a fused silica birefringent filter, with a diameter of 12.7mm and a thickness of 2mm. The laser coupling output element 24 is a plano-concave output mirror, with a dielectric film layer with a 2% transmittance for the 950nm laser wavelength coated on the concave surface and a dielectric film layer with a high transmittance for the 950nm laser wavelength coated on the plane. Under the above example conditions, the output laser beam 25 obtained can be a laser beam with a central wavelength of 950nm, and its laser wavelength can be tuned by rotating around the normal of the birefringent filter.

[0065] It should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0066] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A laser chip capable of suppressing in-plane amplified spontaneous emission, characterized in that, Including: A chip substrate (1), an integrated multi-layer film high reflector (2), a pump absorption and laser emission region (3), a wide bandgap window layer (4), and an anti-oxidation protection layer (5) that are connected in sequence; And two adjacent sides of the laser chip parallel to the light source are neat and smooth first cleavage edges (6) and second cleavage edges (7). The first cleavage edge (6) and the second cleavage edge (7) respectively correspond to adjacent first grinding edges (8) and second grinding edges (9). The first grinding edge (8) and the second grinding edge (9) are ground off to respectively form a first inclined edge (10) and a second inclined edge (11) that form an angle with the first grinding edge (8) and the second grinding edge (9).

2. The laser chip capable of suppressing in-plane amplified spontaneous emission according to claim 1, wherein The chip substrate (1) includes: It is made of semiconductor or compound semiconductor material, and the lattice constant of the chip substrate (1) matches the lattice constants of the materials used in the integrated multi-layer film high reflector (2), the pump absorption and laser emission region (3), the wide bandgap window layer (4), and the anti-oxidation protection layer (5).

3. The laser chip capable of suppressing in-plane amplified spontaneous emission according to claim 1, characterized in that, The integrated multi-layer film high reflector (2) includes: It is composed of alternating high refractive index material layers (13) and low refractive index material layers (14). The optical thickness of each high refractive index material layer (13) and low refractive index material layer (14) is equal to one quarter of the laser wavelength emitted by the laser chip, and both the high refractive index material layers (13) and the low refractive index material layers (14) are made of semiconductor or compound semiconductor materials.

4. The laser chip capable of suppressing in-plane amplified spontaneous emission according to claim 1, wherein The pump absorption and laser emission region (3) includes: It is composed of alternating pump absorption layers (15) and laser emission layers (16). The sum of the thicknesses of each pump absorption layer (15) and laser emission layer (16) is equal to one half of the laser wavelength emitted by the laser chip, and both the pump absorption layers (15) and the laser emission layers (16) are made of semiconductor or compound semiconductor materials.

5. The laser chip capable of suppressing in-plane amplified spontaneous emission according to claim 4, characterized in that, The wide bandgap window layer (4) includes: The potential barrier of the pump absorption layer (15) is higher than that of the laser emission layer (16), and the potential barriers of the wide bandgap window layer (4) are all higher than those of the pump absorption layer (15) and the laser emission layer (16).

6. The laser chip capable of suppressing in-plane amplified spontaneous emission according to claim 1, wherein The anti-oxidation protection layer (5) includes: It is made of semiconductor or compound semiconductor material.

7. The laser chip capable of suppressing in-plane amplified spontaneous emission according to claim 1, characterized in that, The included angle includes: The range of its degree is taken as 2° - 10°.

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