CN115313155A

CN115313155A - Multi-junction vertical cavity surface emitting laser of heterogeneous tunnel junction and preparation method thereof

Info

Publication number: CN115313155A
Application number: CN202211056817.1A
Authority: CN
Inventors: 任翱博; 赵飞云; 巫江; 唐枝婷; 李妍
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2022-08-30
Filing date: 2022-08-30
Publication date: 2022-11-08

Abstract

The invention discloses a multi-junction vertical cavity surface emitting laser of a heterogeneous tunnel junction and a preparation method thereof, relates to the field of semiconductor lasers, and solves the problems of low power density, low quantum efficiency and low tilt efficiency and high absorption loss of the conventional vertical cavity surface emitting laser.

Description

Multi-junction vertical cavity surface emitting laser of heterogeneous tunnel junction and preparation method thereof

Technical Field

The invention relates to the field of semiconductor lasers, in particular to a multi-junction vertical cavity surface emitting laser of a heterogeneous tunnel junction.

Background

Vertical Cavity Surface Emitting Lasers (VCSELs) have the unique advantages of small size, small divergence angle, high beam quality, low cost, easy two-dimensional integration, etc., have attracted extensive research interest in the field of semiconductor lasers in recent years and have also expanded rapidly in the application end market, including: 3D face recognition, laser medical science and beauty, gas detection, smart home, laser radar and the like.

At present, a mainstream VCSEL chip mainly adopts a single-active-region large-aperture (5-10 mu m) structure, so that the optical design difficulty is increased, the light output power density is reduced, and the requirements of high integration level and high power density are difficult to meet. Connecting multiple active regions by highly doped tunnel junctions is currently an effective way to improve power density, quantum efficiency, and skew efficiency. However, in a multi-junction VCSEL, the higher tunneling probability and the reduction of the absorption loss introduced by the tunnel junction are contradictory. Although the selection of the wide band gap material and the reduction of the doping concentration are beneficial to reducing the internal loss introduced by the tunnel junction, the tunneling probability of the tunnel junction is influenced, the voltage drop and the resistance introduced by the tunnel junction are increased, and no tunneling effect is caused in severe cases. On the contrary, if only high tunneling probability is pursued, the narrow band gap material is selected, which causes great absorption loss of the tunnel junction, and also affects various characteristics of the VCSEL laser, and causes the laser to have difficulty in realizing fundamental mode lasing.

Aiming at the problems, the invention designs a high-performance multi-junction vertical cavity surface emitting laser based on a II-type heterogeneous tunnel junction.

Disclosure of Invention

The invention aims to: in order to solve the problems of low power density, quantum efficiency and skew efficiency and high absorption loss of the conventional vertical cavity surface emitting laser, the invention provides a multijunction vertical cavity surface emitting laser of a heterogeneous tunnel junction and a preparation method thereof, which can ensure lower laser threshold and high power, reduce series resistance and absorption between valence bands at the tunnel junction, reduce the resistance by about 40 percent compared with a homogeneous tunnel junction and realize the provision of a high-performance multijunction vertical cavity surface emitting laser.

The invention specifically adopts the following technical scheme for realizing the purpose:

a multi-junction vertical cavity surface emitting laser of a heterogeneous tunnel junction is sequentially provided with a P electrode, a P type Bragg reflector group, a first oxide layer, a first active region, a II type heterogeneous tunnel junction, a second oxide layer, a second active region, an N type Bragg reflector group, a substrate and an N electrode from top to bottom.

Optionally, the type ii heterojunction tunnel junction includes: adjacent p-type heavily doped Al _x Ga _1-x As _y Sb _1-y And n-type heavily doped Al _x Ga _1-x As, adjacent p-type heavily doped Al _x Ga _1-x As _y Sb _1-y And n-type heavily doped Al _x Ga _1-x Both sides of As are respectively p-type lightly doped Al _x Ga _1-x As and n-type lightly doped Al _x Ga _1-x As。

Optionally, wherein the p-type lightly doped and n-type lightly doped Al _x Ga _1-x Al of As _x Ga _1-x The As component varies within the range of: x =0.2-0.4.

Optionally, wherein the p-type heavily doped Al _x Ga _1-x As _y Sb _1-y Al of (2) _x Ga _1-x As _y Sb _1-y The component variation range is as follows: x =0-0.2, y =0.8-1.

Optionally, wherein the n-type heavily doped Al _x Ga _1-x Al of As _x Ga _1-x The As component varies within the range of: x =0-0.1.

Optionally, the p-type lightly doped and n-type lightly doped Al _x Ga _1-x As doping concentration range is 5 x 10 ¹⁷ cm ^-3 —2×10 ¹⁸ cm ^-3 The thickness is 20-100nm.

Optionally, the p-type heavily doped Al _x Ga _1-x As _y Sb _1-y The doping concentration range of (1) is 510 ¹⁹ cm ^-3 —1×10 ²⁰ cm ^-3 The thickness is 5-10nm.

Optionally, the n-type heavily doped Al _x Ga _1-x As doping concentration range is 8 multiplied by 10 ¹⁸ cm ^-3 —3×10 ¹⁹ cm ^-3 The thickness is 10-20nm.

The invention also provides a preparation method of the multi-junction vertical cavity surface emitting laser of the heterogeneous tunnel junction, which comprises the following steps:

s1, sequentially extending an N-type Bragg reflector group, a second active region, a second oxide layer, a II-type heterogeneous tunnel junction, a first active region, a first oxide layer and a P-type Bragg reflector group on a substrate to obtain a first prefabricated member;

s2, manufacturing a P electrode on one side, far away from the first active region, of the P type Bragg reflector group of the first prefabricated member, and manufacturing an N electrode on one side, far away from the N type Bragg reflector group, of the substrate, so that the target laser is obtained.

Compared with the prior art, the invention has the advantages that:

1. according to the heterojunction tunnel junction vertical cavity surface emitting laser and the preparation method thereof, the heterojunction tunnel junction is introduced into the laser, so that the threshold value and the high power of the laser are ensured to be lower, the series resistance and the absorption between valence bands at the tunnel junction are reduced, the resistance of the tunnel junction is about 40% smaller than that of a homogeneous tunnel junction, the high-performance multi-junction vertical cavity surface emitting laser is realized, and the problems of low power density, quantum efficiency and oblique efficiency and high absorption loss of the conventional vertical cavity surface emitting laser are solved.

Drawings

FIG. 1 is a schematic diagram of a structure of a hetero-tunnel junction VCSEL.

FIG. 2 is a schematic diagram of a tunnel junction band structure of a hetero-tunnel junction VCSEL.

Fig. 3 is a schematic diagram of optical and electrical performance test in experiment 1.

Reference numerals are as follows: 1-P electrode, 2-P type Bragg reflector set, 3-first oxide layer, 4-first active region, 5-II type heterogeneous tunnel junction, 6-second oxide layer, 7-second active region, 8-N type Bragg reflector set, 9-substrate and 10-N electrode

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are some, but not all embodiments of the present invention.

Thus, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Detailed Description

Referring to fig. 1, the laser comprises, in order from top to bottom, a P electrode 1, a P-type bragg reflector 2, a first oxide layer 3, a first active region 4, a ii-type hetero-tunnel junction 5, a second oxide layer 6, a second active region 7, an N-type bragg reflector 8, a substrate 9, and an N electrode 10.

It can be understood that the heterojunction tunnel junction vertical cavity surface emitting laser provided by the invention ensures lower laser threshold and high power by introducing the II-type heterojunction tunnel junction 5 into the laser, and reduces the series resistance and the absorption between valence bands at the tunnel junction, so that the resistance of the II-type heterojunction tunnel junction 5 provided by the invention is about 40% smaller than that of a homogeneous tunnel junction, the high-performance multi-junction vertical cavity surface emitting laser is realized, and the problems of low power density, quantum efficiency and oblique efficiency and higher absorption loss of the conventional vertical cavity surface emitting laser are solved.

It is to be understood that in the tunnel junction, on the one hand, to avoid light absorption, the tunnel junction material must be composed of a bandgap semiconductor that is larger than the laser wavelength energy; on the other hand, the tunneling probability increases as the band gap of the semiconductor constituting the tunneling junction decreases, and it is difficult for the short-wavelength vertical cavity surface emitting laser to realize a low-resistance tunneling junction, and thus, it is difficult to simultaneously realize low resistance and low light absorption.

Conventional near-infrared multi-junction vertical cavity surface emitting lasers (e.g., 905, 940, and 980 nm) typically use GaAs homojunctions for the tunnel junction material. However, for a 905nm VCSEL, the fluorescence peak of the active region material at room temperature is around 890nm, the corresponding photon energy is 1.393eV, and the energy gap of the intrinsic GaAs material at room temperature is 1.424eV, which are different by only 31meV. The GaAs homojunction has the potential for intrinsic absorption of photons in this band, taking into account the band gap shrinkage due to the heavy doping band-tail effect and carrier shielding effect, and the intrinsic absorption edge red-shift due to the electric franz-kelidish effect. Therefore, the tunnel junction of the heterojunction is more advantageous.

Specifically, refer to the type ii junction tunneling probability formula:

E _geff ≡E _gp -ΔE _c ＝E _gn -ΔE _v (1) In the formula (1), E _gp And E _gn Shows the band gap energy of the p-side semiconductor and the n-side semiconductor, E _geff Indicating the energy gap between the valence band edge on the p-side and the conduction band edge on the n-side of the hetero-interface. Due to E _geff Less than E _gp And E _gn The tunneling probability of the type II heterogeneous tunnel junction is far larger than that of the homojunction or the type I tunnel junction.

Further, in the type II tunnel junction material, since E _gp And E _gn Greater than the laser wavelength energy, and E _geff Less than the laser wavelength energy, and therefore light absorption can occur near the heterojunction. However, the transition from the valence band edge on the p side to the conduction band edge on the n side of the hetero interface requires the carrier function to penetrate the band gap, and therefore, the penetration probability thereof is not high. In addition, in the vertical cavity surface emitting laser, the II type heterogeneous tunnel junction is generally placed at a standing wave node, so that the light absorption of the II type heterogeneous tunnel junction is very small, the arrangement ensures lower laser threshold and high power, and meanwhile, the resistance of the II type heterogeneous tunnel junction is about 40% smaller than that of a homogeneous tunnel junction, and the resistance of the vertical cavity surface emitting laser is greatly reduced.

Furthermore, according to the multi-junction vertical cavity surface emitting laser of the heterojunction, an oxide layer is arranged on one side of a p region of each active region, and the oxide layer can limit the aperture of a light emitting region, effectively inhibit leakage of electrons and further improve quantum efficiency in a device.

The type II heterogeneous tunnel junction comprises the following components: adjacent p-type heavily doped Al _x Ga _1-x As _y Sb _1-y And n-type heavily doped Al _x Ga _1-x As, adjacent p-type heavily doped Al _x Ga _1-x As _y Sb _1-y And n-type heavily doped Al _x Ga _1-x Both sides of As are respectively p-type lightly doped Al _x Ga _1-x As and n-type lightly doped Al _x Ga _1-x As. It should be noted that Al is introduced into the tunnel junction _x Ga _1- _x As _y Sb _1-y With Al _x Ga _1-x As two materials, the tunnel junction has a heterostructure, and light absorption at the heterostructure is small, so that a lower laser threshold value, a smaller resistance, a larger output power and excellent photoelectric performance can be realized at the heterostructure.

In some embodiments of the present invention, the p-type lightly doped Al and the n-type lightly doped Al are _x Ga _1-x Al of As _x Ga _1-x The As component varies within the range of: x =0.2-0.4.

Wherein the p-type lightly doped and n-type lightly doped Al _x Ga _1-x Al of As _x Ga _1-x The As component preferably varies in the range of x =0.3.

In some embodiments of the present invention, the p-type heavily doped Al is _x Ga _1-x As _y Sb _1-y Al of (2) _x Ga _1-x As _y Sb _1-y The component variation range is as follows: x =0-0.2, y =0.8-1.

Wherein the p-type heavily doped Al _x Ga _1-x As _y Sb _1-y Al of (2) _x Ga _1-x As _y Sb _1-y The composition variation range is preferably x =0.1, y =0.9.

In some embodiments of the present invention, the heavily n-doped Al is doped _x Ga _1-x Al of As _x Ga _1-x The As component varies within the range of: x =0-0.1.

Wherein the n-type heavily doped Al _x Ga _1-x Al of As _x Ga _1-x The As component preferably varies in the range of x =0.05.

In some embodiments of the present invention, the p-type lightly doped Al and the n-type lightly doped Al are as described above _x Ga _1-x As doping concentration range is 5X 10 ¹⁷ cm ^-3 —2×10 ¹⁸ cm ^-3 The thickness is 20-100nm.

Wherein the p-type lightly doped and n-type lightly doped Al _x Ga _1-x As doping concentration range is 1 x 10 ¹⁸ cm ^-3 And the thickness is 60nm.

In some embodiments of the present invention, the p-type heavily doped Al is _x Ga _1-x As _y Sb _1-y Has a doping concentration range of 5 × 10 ¹⁹ cm ^-3 —1×10 ²⁰ cm ^-3 The thickness is 5-10nm.

Wherein the p-type heavily doped Al _x Ga _1-x As _y Sb _1-y Preferably in the range of 1 × 10 ²⁰ cm ^-3 The thickness was 8nm.

In some embodiments of the present invention, the heavily n-doped Al is doped _x Ga _1-x As doping concentration range is 8 multiplied by 10 ¹⁸ cm ^-3 —3×10 ¹⁹ cm ^-3 The thickness is 10-20nm.

Wherein the n-type heavily doped Al _x Ga _1-x The doping concentration range of As is preferably 8X 10 ¹⁸ 、1×10 ¹⁹ 、3×10 ¹⁹ cm ^-3 The thickness is 10, 12, 15 and 20nm.

The invention also provides a preparation method of the heterogeneous tunnel junction vertical cavity surface emitting laser, which comprises the following steps:

s1, sequentially extending an N-type Bragg reflector group 8, a second active region 7, a second oxide layer 6, a II-type heterogeneous tunnel junction 5, a first active region 4, a first oxide layer 3 and a P-type Bragg reflector group 2 on a substrate 9 to obtain a first prefabricated part;

s2, manufacturing a P electrode 1 on one side, far away from the first active region 4, of the P-type Bragg reflector group 2 of the first prefabricated member, and manufacturing an N electrode 10 on one side, far away from the N-type Bragg reflector group 8, of the substrate 9, so that the target laser is obtained.

GaAs substrates are preferred in the present invention.

The P-electrode 1 and the N-electrode 10 of the present invention are made of any one of gold, copper, graphite, silver, and tin.

It should be noted that, in the specific epitaxy process, buffer layers are further present between the already involved P-type bragg reflector 2, first oxide layer 3, first active region 4, ii-type hetero-tunnel junction 5, second oxide layer 6, second active region 7, N-type bragg reflector 8, and the like, and parameters are adjusted according to actual preparation requirements to perform epitaxy on each buffer layer, so as to meet actual requirements.

In some embodiments of the present invention, the epitaxy method may be a Metal Organic Chemical Vapor Deposition (MOCVD) method or a Molecular Beam Epitaxy (MBE) method.

Example 1

In this embodiment, the type ii heterogeneous tunnel junction includes: adjacent p-type heavily doped Al _0.15 Ga _0.85 As _0.95 Sb _0.05 And n-type heavily doped Al _0.1 Ga _0.9 As, adjacent p-type heavily doped Al _0.15 Ga _0.85 As _0.95 Sb _0.05 And n-type heavily doped Al _0.1 Ga _0.9 Both sides of As are respectively p-type lightly doped Al _0.3 Ga _0.7 As and n-type lightly doped Al _0.2 Ga _0.7 As。

Wherein, the p type is lightly doped with Al _0.3 Ga _0.7 As and n-type lightly doped Al _0.2 Ga _0.7 As doping concentration range is 5X 10 ¹⁷ cm ^-3 The thickness is 20nm; p-type heavily doped Al _0.15 Ga _0.85 As _0.95 Sb _0.05 Has a doping concentration range of 5 × 10 ¹⁹ cm ^-3 The thickness is 6nm; n-type heavily doped Al _0.1 Ga _0.9 As doping concentration range is 8 multiplied by 10 ¹⁸ cm ^-3 The thickness was 11nm.

Example 2

In this embodiment, the type ii heterojunction tunnel junction includes: adjacent p-type heavily doped Al _0.2 Ga _0.8 As _0.9 Sb _0.1 And n-type heavily doped Al _0.1 Ga _0.9 As, adjacent p-type heavily doped Al _0.15 Ga _0.85 As _0.95 Sb _0.05 And n-type heavily doped Al _0.1 Ga _0.9 Both sides of As are respectively p-type lightly doped Al _0.2 Ga _0.8 As and n-type lightly doped Al _0.2 Ga _0.8 As。

Wherein, the p type is lightly doped with Al _0.2 Ga _0.8 As and n-type lightly doped Al _0.2 Ga _0.8 As doping concentration range is 1 x 10 ¹⁸ cm ^-3 The thickness is 60nm; p-type heavily doped Al _0.2 Ga _0.8 As _0.9 Sb _0.1 Has a doping concentration range of 0.5X 10 ²⁰ cm ^-3 The thickness is 8nm; and n-type heavily doped Al _0.1 Ga _0.9 As doping concentration range is 2 x 10 ¹⁹ cm ^-3 The thickness is 15nm.

Example 3

In this embodiment, the type ii heterojunction tunnel junction includes: adjacent p-type heavily doped Al _0.15 Ga _0.85 As _0.95 Sb _0.05 And n-type heavily doped Al _0.1 Ga _0.9 As, adjacent p-type heavily doped Al _0.2 Ga _0.8 As _0.9 Sb _0.1 And n-type heavily doped Al _0.1 Ga _0.9 Both sides of As are respectively p-type lightly doped Al _0.2 Ga _0.8 As and n-type lightly doped Al _0.2 Ga _0.8 As。

Wherein, the p type is lightly doped with Al _0.2 Ga _0.8 As and n-type lightly doped Al _0.2 Ga _0.8 As doping concentration range is 2 x 10 ¹⁸ cm ^-3 The thickness is 100nm; p-type heavily doped Al _0.15 Ga _0.85 As _0.95 Sb _0.05 Has a doping concentration range of 1 × 10 ²⁰ cm ^-3 The thickness is 10nm; and n-type heavily doped Al _0.1 Ga _0.9 As doping concentration range is 3 x 10 ¹⁹ cm ^-3 And the thickness is 20nm.

Further, in order to verify the optical and electrical properties of the emitting laser according to the present invention, the following test examples were performed.

Test example for testing optical and electrical properties of a transmitting laser

1.1 design of the experiment

Two treatment groups were set up for the experiment, the experimental group being Al according to example 1 _0.1 Ga _0.9 As/Al _0.15 Ga _0.85 As _0.95 Sb _0.05 The three-junction vertical cavity surface emitting laser of the type II heterogeneous tunnel junction adopts a vertical cavity surface emitting laser of a common homogeneous tunnel junction as a reference group, and optical and electrical performance tests are carried out on the three-junction vertical cavity surface emitting laser under the same test conditions.

The test results are shown in FIG. 3, in which the dot-dash line represents a control group (VCSEL of ordinary GaAs homogeneous tunnel junction) and the solid line represents an experimental group (Al) _0.1 Ga _0.9 As/Al _0.15 Ga _0.85 As _0.95 Sb _0.05 Type ii heterojunction tunnel junction vertical cavity surface emitting lasers).

After the test, a current-power curve representing the optical performance and a current-voltage curve representing the electrical performance are respectively obtained.

1.2 analysis of results

Referring to the current-power curve of fig. 3, it can be seen that in terms of optical performance, the lasing threshold of the experimental group is 1.1mA, while the lasing threshold of the control group is 1.2mA, and it can be seen that the lasing thresholds of the two are not much different, because the type ii hetero-tunnel junction Al is used _x Ga _1-x As/Al _x Ga _1-x As _y Sb _1-y No increase in absorption loss. It can be seen that the differential resistance and the diagonal efficiency of the experimental group are better than those of the control group under the condition of ensuring that the lasing threshold is not changed, and therefore, the heterojunction tunnel junction vertical cavity surface emitting laser in the embodiment 1 has higher photoelectric conversion efficiency.

Referring to the current-voltage curve, the curve of the experimental group is steeper in terms of electrical properties, i.e., the differential resistance of the experimental group is smaller compared to the control group. Visible, type II tunnel junction Al _x Ga _1-x As/Al _x Ga _1-x As _y Sb _1-y Having a shorter tunneling distance increases the tunneling probability of electrons, thereby reducing the differential resistance.

By combining the two curves, compared with a control group, the experimental group has better differential resistance and oblique line efficiency and higher photoelectric conversion efficiency under the condition of ensuring that the lasing threshold is not changed.

In summary, the multi-junction vertical cavity surface emitting laser of the hetero-tunnel junction according to the present invention ensures a lower laser threshold and a high power by introducing the hetero-tunnel junction into the laser, and reduces the series resistance and the absorption between valence bands at the tunnel junction, so that the resistance of the tunnel junction according to the present invention is about 40% smaller than that of a homogeneous tunnel junction, thereby implementing a high performance multi-junction vertical cavity surface emitting laser, and solving the problems of low power density, quantum efficiency, and skew efficiency, and high absorption loss of the conventional vertical cavity surface emitting laser.

The above embodiment is only one embodiment of the present invention, and the description thereof is specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A multijunction vertical cavity surface emitting laser of a heterojunction tunnel junction, characterized in that: the laser comprises a P electrode, a P type Bragg reflector group, a first oxide layer, a first active region, a II type heterogeneous tunnel junction, a second oxide layer, a second active region, an N type Bragg reflector group, a substrate and an N electrode from top to bottom in sequence.

2. The multijunction vertical-cavity surface-emitting laser of a heterojunction according to claim 1, wherein: the type II heterojunction tunnel junction comprises: adjacent p-type heavily doped Al _x Ga _1-x As _y Sb _1-y And n-type heavily doped Al _x Ga _1-x As, adjacent p-type heavily doped Al _x Ga _1-x As _y Sb _1-y And n-type heavily doped Al _x Ga _1-x Both sides of As are respectively p-type lightly doped Al _x Ga _1-x As and n-type lightly doped Al _x Ga _1-x As。

3. A heterojunction vertical cavity surface emitting laser according to claim 2, wherein: wherein the p-type lightly doped and n-type lightly doped Al _x Ga _1-x Al of As _x Ga _1-x The As component varies within the range of: x =0.2-0.4.

4. The multijunction vertical-cavity surface-emitting laser of a heterojunction according to claim 2, wherein: wherein the p-type heavily doped Al _x Ga _1-x As _y Sb _1-y Al of (2) _x Ga _1-x As _y Sb _1-y The component variation range is as follows: x =0-0.2, y =0.8-1.

5. The multijunction vertical-cavity surface-emitting laser of a heterojunction according to claim 2, wherein: wherein the n-type heavily doped Al _x Ga _1-x Al of As _x Ga _1-x The As component varies within the range of:

x＝0-0.1。

6. the multijunction vertical-cavity surface-emitting laser of claim 3, wherein: the p-type lightly doped and n-type lightly doped Al _x Ga _1-x As doping concentration range is 5X 10 ¹⁷ cm ^-3 —2×10 ¹⁸ cm ^-3 The thickness is 20-100nm.

7. The heterojunction vertical cavity surface-emitting laser according to claim 4, wherein: the p-type heavily doped Al _x Ga _1-x As _y Sb _1-y Has a doping concentration range of 5 × 10 ¹⁹ cm ^-3 —1×10 ²⁰ cm ^-3 The thickness is 5-10nm.

8. A heterojunction vertical cavity surface emitting laser according to claim 5, wherein: the n-type heavily doped Al _x Ga _1-x As doping concentration range is 8 multiplied by 10 ¹⁸ cm ^-3 —3×10 ¹⁹ cm ^-3 The thickness is 10-20nm.

9. A method of fabricating a multi-junction vertical cavity surface emitting laser of a heterojunction as claimed in any of claims 1 to 8, wherein: the method comprises the following steps:

s2, manufacturing a P electrode on one side, far away from the first active region, of the P type Bragg reflector group of the first prefabricated member, and manufacturing an N electrode on one side, far away from the N type Bragg reflector group, of the substrate to obtain the target laser.