A VCSEL with an asymmetric confinement layer and a method for manufacturing the same

Abstract

The present invention provides a VCSEL with an asymmetric confinement layer and a manufacturing method thereof, wherein the VCSEL comprises a substrate, and an N-type DBR layer, an N-type confinement layer, an active region, a P-type confinement layer, an oxide layer and a P-type DBR layer stacked on the substrate in sequence from bottom to top; the N-type confinement layer comprises a plurality of first AlGaAs layers arranged in sequence from bottom to top, and the P-type confinement layer comprises a plurality of second AlGaAs layers arranged in sequence from bottom to top; the Al component of the plurality of first AlGaAs layers presents a fluctuating step distribution as the thickness increases, and the Al component of the plurality of second AlGaAs layers presents a fluctuating step distribution as the thickness increases, and the N-type confinement layer and the P-type confinement layer are mutually asymmetric structures. Electrons and holes are effectively confined in the active region, and the radiation recombination is high; and the light field distribution can be changed, light absorption and light scattering can be reduced, and gain can be improved.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to a VCSEL with an asymmetric confinement layer and a manufacturing method thereof. Background Art

[0002] VCSEL, whose full name is Vertical Cavity Surface Emitting Laser, is developed based on gallium arsenide semiconductor materials. Different from other light sources such as LED (light emitting diode) and LD (Laser Diode), it has the advantages of small size, circular output spot, single longitudinal mode output, small threshold current, low price, easy integration into large-area arrays, etc. It is widely used in optical communication, optical interconnection, optical storage and other fields.

[0003] VCSEL is usually composed of a substrate, an N-type DBR layer, a confinement layer, a waveguide layer, an MQW, a waveguide layer, a confinement layer, an oxide layer and a P-type DBR layer stacked in sequence. In the existing VCSEL structure, the confinement layer adopts a single structure, and the waveguide layer has a gradient waveguide layer and a symmetric waveguide layer. The electron confinement ability of a single confinement layer is limited, and it is difficult to effectively diffuse electrons, and it is difficult for holes to enter the active area, and the radiation recombination is low. The gradient waveguide layer is difficult to control the light field distribution, and the symmetric waveguide layer, because the light field is biased towards the P type, C doping forms impurity absorption and impurity scattering of light to a certain extent. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a VCSEL with an asymmetric confinement layer and a method for manufacturing the same, which can effectively increase radiation recombination, change the light field distribution, reduce light absorption and light scattering, and improve output power.

[0005] The technical solution adopted by the present invention is:

[0006] A VCSEL with an asymmetric confinement layer comprises a substrate, and an N-type DBR layer, an N-type confinement layer, an active region, a P-type confinement layer, an oxide layer and a P-type DBR layer sequentially stacked on the substrate from bottom to top;

[0007] The N-type confinement layer comprises a plurality of first AlGaAs layers sequentially arranged from bottom to top, and the P-type confinement layer comprises a plurality of second AlGaAs layers sequentially arranged from bottom to top;

[0008] The Al components of the first AlGaAs layers present a fluctuating step distribution as the thickness increases, the Al components of the second AlGaAs layers present a fluctuating step distribution as the thickness increases, and the N-type confinement layer and the P-type confinement layer are mutually asymmetric structures.

[0009] Optionally, the number of layers of the first AlGaAs layer is the same as the number of layers of the second AlGaAs layer, the distribution trend of the Al component of the multiple second AlGaAs layers with increasing thickness is symmetrical to the distribution trend of the Al component of the first AlGaAs layer, and the Al component of each layer of the first AlGaAs layer is higher than the Al component of the second AlGaAs layer corresponding to the same level in the stepped distribution.

[0010] Optionally, the Al components of the first AlGaAs layers are distributed in alternating steps with increasing thickness.

[0011] Optionally, the Al components of the first AlGaAs layers are distributed in alternating steps of low and high as the thickness increases.

[0012] Optionally, the Al components of the multiple layers of the first AlGaAs layer present a step distribution that fluctuates and decreases with increasing thickness.

[0013] Optionally, the Al components of the multiple layers of the first AlGaAs layer present a step distribution that fluctuates and increases with increasing thickness.

[0014] Optionally, the number of layers of the first AlGaAs layer and the second AlGaAs layer are two respectively.

[0015] Optionally, the number of layers of the first AlGaAs layer and the second AlGaAs layer are 6 layers respectively, and the Al composition ranges of the 6 first AlGaAs layers from bottom to top are: 0.75-0.85, 0.3-0.6, 0.65-0.75, 0.2-0.6, 0.55-0.65 and 0.1-0.6, and the Al composition ranges of the 6 second AlGaAs layers from bottom to top are: 0.1-0.6, 0.55-0.65, 0.2-0.6, 0.65-0.75, 0.3-0.6 and 0.75-0.85.

[0016] Optionally, the sum of the product of the thickness of each of the first AlGaAs layers and the refractive index and the sum of the product of the thickness of each of the second AlGaAs layers and the refractive index is one wavelength.

[0017] Optionally, the sum of the products of the thickness of each of the first AlGaAs layers and the refractive index is greater than the sum of the products of the thickness of each of the second AlGaAs layers and the refractive index.

[0018] Optionally, the product of the thickness and the refractive index of the first AlGaAs layer is greater than the product of the thickness and the refractive index of the second AlGaAs layer at the same level.

[0019] Optionally, the thickness of each of the first AlGaAs layers and each of the second AlGaAs layers increases with the increase of Al component.

[0020] Optionally, the sum of the products of the thickness of each of the first AlGaAs layers and the refractive index is three fifths of a wavelength, and the sum of the products of the thickness of each of the second AlGaAs layers and the refractive index is two fifths of a wavelength.

[0021] Optionally, it further includes a buffer layer and a protective layer, wherein the buffer layer is stacked between the substrate and the N-type DBR layer, and the protective layer is stacked on the P-type DBR layer.

[0022] Another technical solution adopted by the present invention is:

[0023] A method for manufacturing a VCSEL having an asymmetric confinement layer, comprising:

[0024] Growing an N-type DBR layer on a substrate;

[0025] Growing multiple layers of first AlGaAs layers from bottom to top on the N-type DBR layer to form an N-type confinement layer, wherein Al components of the multiple layers of the first AlGaAs layers are fluctuating in a step distribution as thickness increases;

[0026] growing an active region on the N-type confinement layer;

[0027] Growing multiple layers of second AlGaAs layers from bottom to top on the active region to form a P-type confinement layer, wherein the Al components of the multiple layers of the first AlGaAs layers are in a fluctuating step distribution as the thickness increases, and the N-type confinement layer and the P-type confinement layer are mutually asymmetric structures;

[0028] growing an oxide layer on the P-type confinement layer;

[0029] A P-type DBR layer is grown on the oxide layer.

[0030] Optionally, the number of layers of the second AlGaAs layer is the same as the number of layers of the first AlGaAs layer, the distribution trend of the Al component of the multiple second AlGaAs layers with increasing thickness is symmetrical to the distribution trend of the Al component of the first AlGaAs layer, and the Al component of each layer of the first AlGaAs layer is higher than the Al component of the second AlGaAs layer corresponding to the same level in the stepped distribution.

[0031] Optionally, the sum of the product of the thickness of each of the first AlGaAs layers and the refractive index and the sum of the product of the thickness of each of the second AlGaAs layers and the refractive index is one wavelength.

[0032] Optionally, the sum of the products of the thickness of each of the first AlGaAs layers and the refractive index is greater than the sum of the products of the thickness of each of the second AlGaAs layers and the refractive index.

[0033] Optionally, the product of the thickness and the refractive index of the first AlGaAs layer is greater than the product of the thickness and the refractive index of the second AlGaAs layer at the same level. N-type DBR layer N-type restriction layer P-type restriction layer P-type DBR layer N-type restriction layer P-type restriction layer N-type DBR layer N-type restriction layer N-type restriction layer P-type restriction layer P-type restriction layer P-type DBR layer

[0034] From the above description, it can be seen that the beneficial effects of the present invention are:

[0035] The P-type confinement layer and the N-type confinement layer are designed with fluctuating Al components. The different Al components form a potential barrier difference. The high potential barrier limits the transition of electrons, reduces electron aggregation and electron overflow, and forms a deep energy level. The P-type confinement layer with fluctuating Al components can better confine electrons in the active area and allow holes to enter the active area more easily, thereby effectively increasing radiation recombination; and, through the low potential barrier and the asymmetric difference setting of the P-type confinement layer and the N-type confinement layer, the light field distribution is changed, so that photons are closer to the N-type, thereby reducing the absorption and scattering of light by impurities and increasing the output power.

[0036] More preferably, by adjusting the thickness, it can have the effect of electron blocking and meet the optical wavelength, further changing the light field distribution, while improving the gain spectrum position, further increasing the output power and improving the slope efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0038] Figure 1 A schematic diagram of the structure of a VCSEL with an asymmetric confinement layer according to an embodiment of the present invention;

[0039] Figure 2a-2e A schematic diagram showing the variation of Al composition with thickness of a VCSEL with an asymmetric confinement layer according to another embodiment of the present invention;

[0040] Figure 3a-3b A schematic diagram showing the variation of Al composition with thickness of a VCSEL with an asymmetric confinement layer according to another embodiment of the present invention;

[0041] Figure 4a-4b A schematic diagram showing the variation of Al composition with thickness of a VCSEL with an asymmetric confinement layer according to another embodiment of the present invention;

[0042] Figure 5 A schematic diagram showing the variation of Al composition with thickness of a VCSEL with an asymmetric confinement layer according to another embodiment of the present invention;

[0043] Figure 6 FIG. 4 is a schematic structural diagram of a VCSEL with an asymmetric confinement layer according to a specific example of the present invention.

[0044] Icon Description:

[0045] 1. Substrate; 2. Buffer layer; 3. N-type DBR layer; 4. N-type confinement layer; 41. First AlGaAs layer; 5. Active region; 6. P-type confinement layer; 61. Second AlGaAs layer; 7. Oxide layer; 8. P-type DBR layer; 9. Protective layer. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0047] like Figure 1 As shown, an embodiment of the present invention provides a VCSEL with an asymmetric confinement layer, comprising a substrate 1, and a buffer layer 2, an N-type DBR layer 3, an N-type confinement layer 4, an active region 5, a P-type confinement layer 6, an oxide layer 7, a P-type DBR layer 8 and a protective layer 9 stacked on the substrate 1 from bottom to top.

[0048] The N-type confinement layer 4 includes a plurality of first AlGaAs layers 41 sequentially arranged from bottom to top, and the P-type confinement layer 6 includes a plurality of second AlGaAs layers 61 sequentially arranged from bottom to top.

[0049] The Al component of the multilayer first AlGaAs layer 41 is fluctuating in a step distribution as the thickness increases, and the Al component of the multilayer second AlGaAs layer 61 is fluctuating in a step distribution as the thickness increases, and the N-type confinement layer 4 and the P-type confinement layer 6 are asymmetric. The number of layers of the first AlGaAs layer 41 and the second AlGaAs layer 61 can be two layers or more layers, and the specific number of layers and Al component distribution can be set in a variety of ways, such as Figure 2a-2e The diagrams are respectively a schematic diagram of the variation of Al composition with thickness, wherein the abscissa represents thickness, the ordinate represents Al composition, p represents the first AlGaAs layer, and q represents the second AlGaAs layer. It can be understood that Figure 2a-2e It is only a schematic diagram of a partial implementation of this embodiment and is not a limitation of the invention.

[0050] As an implementation, the number of the first AlGaAs layer 41 is the same as the number of the second AlGaAs layer, the distribution trend of the Al component of the multiple second AlGaAs layers 61 with increasing thickness is symmetrical with the distribution trend of the Al component of the first AlGaAs layer 41, and the Al component of each first AlGaAs layer 41 is higher than the Al component of the second AlGaAs layer 61 corresponding to the same level in the step distribution. In this implementation, the asymmetric confinement layer is realized in the form of symmetrical distribution trend and asymmetric composition, and the light field distribution is changed by the difference in composition between the N-type confinement layer 4 and the P-type confinement layer 6, thereby reducing the absorption and scattering of light by impurities and improving the output power.

[0051] Another embodiment of the present invention provides a VCSEL with an asymmetric confinement layer, which is different from the above embodiment in that the Al component of the multi-layer first AlGaAs layer 41 is distributed in a stepped manner with alternating highs and lows as the thickness increases. Specifically, the Al component of the multi-layer first AlGaAs layer 41 can be distributed in a stepped manner with fluctuating decreases as the thickness increases, or can be distributed in a stepped manner with fluctuating increases as the thickness increases. Taking the first AlGaAs layer and the second AlGaAs layer as three layers as an example, schematic diagrams of the change of the Al component with thickness are as follows: Figure 3a and Figure 3b As shown, the abscissa represents thickness, the ordinate represents Al composition, p represents the first AlGaAs layer, and q represents the second AlGaAs layer.

[0052] As another implementation, the Al component of the multi-layer first AlGaAs layer 41 may also be distributed in a step-like manner with alternating low and high as the thickness increases. Specifically, the Al component of the multi-layer first AlGaAs layer 41 may be distributed in a step-like manner with fluctuating decreases as the thickness increases, or may be distributed in a step-like manner with fluctuating increases as the thickness increases. Taking the first AlGaAs layer and the second AlGaAs layer as three layers as an example, schematic diagrams of the variation of the Al component with thickness are as follows: Figure 4a and Figure 4b As shown, the abscissa represents thickness, the ordinate represents Al composition, p represents the first AlGaAs layer, and q represents the second AlGaAs layer.

[0053] Another embodiment of the present invention provides a VCSEL with an asymmetric confinement layer, which is different from the above embodiment in that the number of layers of the first AlGaAs layer 41 and the second AlGaAs layer 61 are 6, respectively, and the Al composition ranges of the 6 first AlGaAs layers 41 from bottom to top are: 0.75-0.85, 0.3-0.6, 0.65-0.75, 0.2-0.6, 0.55-0.65 and 0.1-0.6, respectively, and the Al composition ranges of the 6 second AlGaAs layers from bottom to top are: 0.1-0.6, 0.55-0.65, 0.2-0.6, 0.65-0.75, 0.3-0.6 and 0.75-0.85. The schematic diagram of the variation of Al composition with thickness is shown in FIG. Figure 5 As shown, the abscissa represents thickness, the ordinate represents Al composition, p represents the first AlGaAs layer, and q represents the second AlGaAs layer. It can be understood by those skilled in the art that the above ranges of the number of layers and Al composition are not limitations of the present invention.

[0054] Another embodiment of the present invention provides a VCSEL with an asymmetric confinement layer, which is different from the above embodiment in that the sum of the product of the thickness of each first AlGaAs layer 41 and the refractive index and the sum of the product of the thickness of each second AlGaAs layer 61 and the refractive index is one wavelength.

[0055] As an implementation manner, the sum of the products of the thickness and the refractive index of each layer of the first AlGaAs layer 41 is greater than the sum of the products of the thickness and the refractive index of each layer of the second AlGaAs layer 61.

[0056] Specifically, the product of the thickness and the refractive index of the first AlGaAs layer 41 is greater than the product of the thickness and the refractive index of the second AlGaAs layer 61 at the same level.

[0057] Specifically, the sum of the product of the thickness and the refractive index of each first AlGaAs layer 41 is three-fifths of a wavelength, and the sum of the product of the thickness and the refractive index of each second AlGaAs layer 61 is two-fifths of a wavelength. It can be understood by those skilled in the art that three-fifths and two-fifths are not limitations of the present invention, and the present invention can also adopt other numerical settings, as long as the sum is one wavelength and the sum of the product of the thickness and the refractive index of each first AlGaAs layer 41 is greater than the sum of the product of the thickness and the refractive index of the second AlGaAs layer 61.

[0058] The Al component affects the refractive index. This embodiment forms an electron barrier with a limiting effect by setting the Al component and thickness, and meets the optical wavelength, changes the light field distribution, and improves the gain spectrum position, thereby better improving the output power and slope efficiency. It has the functions of both a limiting layer and a waveguide layer, saving the setting of a waveguide layer.

[0059] As an implementation manner, the thickness of each of the first AlGaAs layers 41 and each of the second AlGaAs layers 61 increases with the increase of Al composition.

[0060] Another embodiment of the present invention provides a method for manufacturing a VCSEL having an asymmetric confinement layer, comprising:

[0061] A method for manufacturing a VCSEL having an asymmetric confinement layer, characterized by comprising:

[0062] Growing an N-type DBR layer on a substrate;

[0063] Growing multiple layers of first AlGaAs layers from bottom to top on the N-type DBR layer to form an N-type confinement layer, wherein Al components of the multiple layers of the first AlGaAs layers are fluctuating in a step distribution as thickness increases;

[0064] growing an active region on the N-type confinement layer;

[0065] Growing multiple layers of second AlGaAs layers from bottom to top on the active region to form a P-type confinement layer, wherein the Al components of the multiple layers of the first AlGaAs layers are in a fluctuating step distribution as the thickness increases, and the N-type confinement layer and the P-type confinement layer are mutually asymmetric structures;

[0066] growing an oxide layer on the P-type confinement layer;

[0067] A P-type DBR layer is grown on the oxide layer.

[0068] The specific structures of the N-type confinement layer and the P-type confinement layer refer to the above-mentioned VCSEL with an asymmetric confinement layer, which will not be described in detail here.

[0069] The following is a specific example to illustrate:

[0070] Please refer to Figure 5 and Figure 6A VCSEL with an asymmetric confinement layer comprises a substrate 1, and a buffer layer 2, an N-type DBR layer 3, an N-type confinement layer 4, an active region 5, a P-type confinement layer 6, an oxide layer 7, a P-type DBR layer 8 and a protective layer 9 stacked on the substrate 1 from bottom to top; the N-type confinement layer 4 comprises AlGaAs layers p1-p6 arranged from bottom to top, and the Al component thereof presents a stepped distribution with alternating high and low and fluctuating downward with increasing thickness, and the specific arrangement is as follows:

[0071] AlGaAs layer p1, Al composition ranges from 0.75-0.85, doping is 5E17-3E18 cm -3 , thickness is a1, refractive index is M1; this layer mainly provides a high energy band barrier to limit the transition of electrons;

[0072] AlGaAs layer p2, Al composition ranges from 0.3-0.6, doping is 5E17-3E18 cm -3 , thickness is a2, refractive index is M2; this layer obtains high refractive index through Al component, making photons closer to N type, thereby achieving the effect of reducing impurity absorption and scattering and improving gain;

[0073] AlGaAs layer p3, Al composition ranges from 0.65-0.75, doping is 5E17-3E18 cm -3 , thickness is a3, refractive index is M3; this layer again provides a high energy band barrier, better restricts electron transition, thereby reducing electron overflow, reducing the generation of deep energy levels, reducing electron aggregation, and generating Joule heat, affecting power;

[0074] AlGaAs layer p4, Al composition ranges from 0.2-0.6, doping is 5E17-3E18 cm -3 , thickness is a4, refractive index is M4; due to the single refractive index and thickness, it is difficult to significantly improve the light field. This layer obtains a higher refractive index through a lower Al component, making the photons closer to the N type, thereby reducing impurity absorption and scattering and improving the gain;

[0075] AlGaAs layer p5, Al composition ranges from 0.55-0.65, doping is 5E17-3E18 cm -3 , thickness is a5, refractive index is M5; this layer again provides a high energy band barrier, better confines electrons, thereby reducing electron overflow, reducing the generation of deep energy levels, reducing electron aggregation, and generating Joule heat, affecting power;

[0076] AlGaAs layer p6, Al composition ranges from 0.1-0.6, doping is 5E17-3E18 cm -3, with a thickness of a6 and a refractive index of M6; this layer obtains a higher refractive index through a lower Al component, making the photons closer to the N type, thereby reducing impurity absorption and scattering and increasing the gain;

[0077] The above-mentioned a1*M1+a2*M2+a3*M3+a4*M4+a5*M5+a6*M6=3 / 5*wavelength, this setting of 6 layers of optical wavelengths satisfies the cavity length and provides better gain and light field distribution.

[0078] The P-type confinement layer 6 includes AlGaAs layers q1-q6 arranged in sequence from bottom to top, and the Al component thereof presents a step distribution with alternating low and high and fluctuating upward as the thickness increases, the Al component of the AlGaAs layer q1 is lower than the Al component of the AlGaAs layer p6, the Al component of the AlGaAs layer q2 is lower than the Al component of the AlGaAs layer p5, the Al component of the AlGaAs layer q3 is lower than the Al component of the AlGaAs layer p4, the Al component of the AlGaAs layer q4 is lower than the Al component of the AlGaAs layer p3, the Al component of the AlGaAs layer q5 is lower than the Al component of the AlGaAs layer p2, and the Al component of the AlGaAs layer q6 is lower than the Al component of the AlGaAs layer p1, and the specific arrangement is as follows:

[0079] AlGaAs layer q1, Al composition ranges from 0.1-0.6, doping is 5E17-3E18 cm -3 , with a thickness of b1 and a refractive index of N1; this layer improves the restriction of electrons and reduces electron overflow by changing the energy band;

[0080] AlGaAs layer q2, Al composition ranges from 0.55-0.65, doping is 5E17-3E18 cm -3 , with a thickness of b2 and a refractive index of N2; this layer changes the refractive index through a special component setting, thereby changing the light field to be more biased towards N type;

[0081] AlGaAs layer q3, Al composition ranges from 0.2-0.6, doping is 5E17-3E18 cm -3 , with a thickness of b3 and a refractive index of N3; this layer improves the restriction of electrons by changing the energy band, reduces electron overflow, reduces the recombination of electrons and holes, and forms a deep energy level;

[0082] AlGaAs layer q4, Al composition ranges from 0.65-0.75, doping is 5E17-3E18 cm -3 , with a thickness of b4 and a refractive index of N4; this layer changes the refractive index by changing the composition, thereby changing the light field to be more biased towards N type;

[0083] AlGaAs layer q5, Al composition ranges from 0.3-0.6, doping is 5E17-3E18 cm -3 , thickness is b5, refractive index is N5; this layer improves the restriction of electrons by changing the energy band, reduces electron overflow, reduces the recombination of electrons and holes, and forms a deep energy level;

[0084] AlGaAs layer q6, Al composition ranges from 0.75-0.85, doping is 5E17-3E18 cm -3 , thickness is b6, refractive index is N6; this layer changes the refractive index by component setting, changing the light field to be more biased towards N type;

[0085] The above b1*N1+b2*N2+b3*N3+b4*N4+b5*N5+b6*N6=2 / 5*wavelength. This setting of 6 layers of optical wavelengths satisfies the cavity length, and provides better gain and light field distribution through the coordinated setting of thickness and refractive index.

[0086] It should be noted that this example is intended to better explain the content of the present invention and should not be regarded as a limitation of the present invention.

[0087] In summary, the VCSEL with an asymmetric confinement layer and the manufacturing method thereof of the present invention can effectively confine electrons and holes in the active region, with high radiation recombination; and can change the light field distribution, reduce light absorption and light scattering, and improve gain.

[0088] It can be understood that the orientation or position relationship indicated by "upper" and "lower" etc. described in the present invention is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms cannot be understood as limiting the present invention.

[0089] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0090] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may 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 the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A VCSEL having an asymmetric confinement layer, characterized in that: It comprises a substrate, and an N-type DBR layer, an N-type restriction layer, an active region, a P-type restriction layer, an oxide layer and a P-type DBR layer sequentially stacked on the substrate from bottom to top; The N-type confinement layer comprises a plurality of first AlGaAs layers sequentially arranged from bottom to top, and the P-type confinement layer comprises a plurality of second AlGaAs layers sequentially arranged from bottom to top; The Al components of the multi-layer first AlGaAs layer present a fluctuating step distribution as the thickness increases, the Al components of the multi-layer second AlGaAs layer present a fluctuating step distribution as the thickness increases, and the N-type confinement layer and the P-type confinement layer are mutually asymmetric structures; The number of the first AlGaAs layer and the second AlGaAs layer are 6 layers respectively, the Al composition ranges of the 6 first AlGaAs layers from bottom to top are: 0.75-0.85, 0.3-0.6, 0.65-0.75, 0.2-0.6, 0.55-0.65 and 0.1-0.6, and the Al composition ranges of the 6 second AlGaAs layers from bottom to top are: 0.1-0.6, 0.55-0.65, 0.2-0.6, 0.65-0.75, 0.3-0.6 and 0.75-0.85; The sum of the product of the thickness of each of the first AlGaAs layers and the refractive index and the sum of the product of the thickness of each of the second AlGaAs layers and the refractive index is one wavelength.

2. The VCSEL with an asymmetric confinement layer according to claim 1, characterized in that: The number of layers of the first AlGaAs layer is the same as the number of layers of the second AlGaAs layer, the distribution trend of the Al component of the multiple second AlGaAs layers with increasing thickness is symmetrical to the distribution trend of the Al component of the first AlGaAs layer, and the Al component of each layer of the first AlGaAs layer is higher than the Al component of the second AlGaAs layer corresponding to the same level in the stepped distribution.

3. The VCSEL with an asymmetric confinement layer according to claim 1, characterized in that: The Al components of the first AlGaAs layers are distributed in a stepped manner with alternating high and low levels as the thickness increases.

4. The VCSEL with an asymmetric confinement layer according to claim 1, characterized in that: The Al components of the first AlGaAs layers are distributed in a stepped manner with alternating low and high levels as the thickness increases.

5. The VCSEL with an asymmetric confinement layer according to claim 1, characterized in that: The Al components of the first AlGaAs layers are distributed in a step-wise manner with a fluctuation as the thickness increases.

6. The VCSEL with an asymmetric confinement layer according to claim 1, characterized in that: The Al components of the first AlGaAs layers are distributed in a fluctuating and ascending stepwise manner as the thickness increases.

7. The VCSEL with an asymmetric confinement layer according to any one of claims 1 to 6, characterized in that: The number of layers of the first AlGaAs layer and the second AlGaAs layer are respectively two.

8. The VCSEL with an asymmetric confinement layer according to claim 1, characterized in that: The sum of the products of the thickness of each of the first AlGaAs layers and the refractive index is greater than the sum of the products of the thickness of each of the second AlGaAs layers and the refractive index.

9. The VCSEL with an asymmetric confinement layer according to claim 1, characterized in that: The product of the thickness and the refractive index of the first AlGaAs layer is greater than the product of the thickness and the refractive index of the second AlGaAs layer at the same level.

10. The VCSEL with an asymmetric confinement layer according to any one of claims 1 to 6, characterized in that: The thickness of each of the first AlGaAs layers and each of the second AlGaAs layers increases with the increase of Al composition.

11. The VCSEL with an asymmetric confinement layer according to any one of claims 1 to 6, characterized in that: The sum of the products of the thickness and the refractive index of each of the first AlGaAs layers is three fifths of a wavelength, and the sum of the products of the thickness and the refractive index of each of the second AlGaAs layers is two fifths of a wavelength.

12. The VCSEL with an asymmetric confinement layer according to any one of claims 1 to 6, characterized in that: The invention also comprises a buffer layer and a protective layer, wherein the buffer layer is stacked between the substrate and the N-type DBR layer, and the protective layer is stacked on the P-type DBR layer.

13. A method for manufacturing a VCSEL having an asymmetric confinement layer, characterized in that: include: Growing an N-type DBR layer on a substrate; Growing multiple layers of first AlGaAs layers from bottom to top on the N-type DBR layer to form an N-type confinement layer, wherein Al components of the multiple layers of the first AlGaAs layers are fluctuating in a step distribution as thickness increases; growing an active region on the N-type confinement layer; Growing multiple layers of second AlGaAs layers from bottom to top on the active region to form a P-type confinement layer, wherein the Al components of the multiple layers of the first AlGaAs layers are in a fluctuating step distribution as the thickness increases, and the N-type confinement layer and the P-type confinement layer are mutually asymmetric structures; growing an oxide layer on the P-type confinement layer; growing a P-type DBR layer on the oxide layer; The number of the first AlGaAs layer and the second AlGaAs layer are 6 layers respectively, the Al composition ranges of the 6 first AlGaAs layers from bottom to top are: 0.75-0.85, 0.3-0.6, 0.65-0.75, 0.2-0.6, 0.55-0.65 and 0.1-0.6, and the Al composition ranges of the 6 second AlGaAs layers from bottom to top are: 0.1-0.6, 0.55-0.65, 0.2-0.6, 0.65-0.75, 0.3-0.6 and 0.75-0.85; The sum of the product of the thickness of each of the first AlGaAs layers and the refractive index and the sum of the product of the thickness of each of the second AlGaAs layers and the refractive index is one wavelength.

14. The method for manufacturing a VCSEL with an asymmetric confinement layer according to claim 13, characterized in that: The number of layers of the second AlGaAs layer is the same as the number of layers of the first AlGaAs layer, and the distribution trend of the Al component of the multiple second AlGaAs layers with increasing thickness is symmetrical to the distribution trend of the Al component of the first AlGaAs layer, and the Al component of each layer of the first AlGaAs layer is higher than the Al component of the second AlGaAs layer corresponding to the same level in the stepped distribution.

15. The method for manufacturing a VCSEL with an asymmetric confinement layer according to any one of claims 13 to 14, characterized in that: The sum of the products of the thickness of each of the first AlGaAs layers and the refractive index is greater than the sum of the products of the thickness of each of the second AlGaAs layers and the refractive index.

16. The method for manufacturing a VCSEL with an asymmetric confinement layer according to any one of claims 13 to 14, characterized in that: The product of the thickness and the refractive index of the first AlGaAs layer is greater than the product of the thickness and the refractive index of the second AlGaAs layer at the same level.

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