A multi-junction vertical cavity surface emitting laser with heterogeneous tunnel junction and a preparation method thereof

Abstract

The invention discloses a multi-junction vertical cavity surface emitting laser with a heterogeneous tunnel junction and a preparation method thereof, relates to the field of semiconductor lasers, solves the problems of low power density, quantum efficiency and slope efficiency and high absorption loss of the existing vertical cavity surface emitting lasers, and the laser comprises, from top to bottom, 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. By introducing the II-type heterogeneous tunnel junction into the laser, a lower laser threshold and high power are ensured, while reducing the series resistance and the absorption between the valence bands at the tunnel junction, thereby realizing a high-performance multi-junction vertical cavity surface emitting laser.

Description

Technical Field

[0001] The invention relates to the field of semiconductor lasers, in particular to a multi-junction vertical cavity surface emitting laser with heterogeneous tunnel junctions. Background Art

[0002] Vertical cavity surface emitting laser (VCSEL) has unique advantages such as small size, small divergence angle, high beam quality, low cost, and easy two-dimensional integration. In recent years, it has aroused widespread research interest in the field of semiconductor lasers and has also expanded rapidly in the application-end market, including: 3D facial recognition, laser medical beauty, gas detection, smart home, lidar and other applications.

[0003] The current mainstream VCSEL chips mainly adopt a single active area large aperture (5-10μm) structure. This approach increases the difficulty of optical design and reduces the light output power density, making it difficult to meet the needs of high integration and high power density. Connecting multiple active areas through highly doped tunnel junctions is currently an effective way to improve power density, quantum efficiency and slope efficiency. However, in multi-junction VCSELs, a higher tunneling probability and reducing the absorption loss introduced by the tunnel junction are contradictory. Although selecting wide bandgap materials and reducing the doping concentration are conducive to reducing the internal loss introduced by the tunnel junction, they will also affect the tunneling probability of the tunnel junction, resulting in an increase in the voltage drop and resistance introduced by the tunnel junction, and in severe cases, there will be no tunneling effect. On the contrary, if you only pursue a high tunneling probability and choose a narrow bandgap material, the absorption loss of the tunnel junction will be very large, which will also affect the characteristics of various aspects of the VCSEL laser and make it difficult for the laser to achieve fundamental mode lasing.

[0004] In view of the above problems, the present invention designs a high-performance multi-junction vertical cavity surface emitting laser based on type II heterojunction. Summary of the invention

[0005] The purpose of the present invention is to solve the problems of low power density, quantum efficiency and slope efficiency and high absorption loss of existing vertical cavity surface emitting lasers. The present invention provides a multi-junction vertical cavity surface emitting laser with a heterogeneous tunnel junction and a preparation method thereof. While ensuring a lower laser threshold and high power, the series resistance and the absorption between the valence bands at the tunnel junction are reduced. The resistance is about 40% smaller than that of a homogeneous tunnel junction, thereby providing a high-performance multi-junction vertical cavity surface emitting laser.

[0006] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0007] A multi-junction vertical cavity surface emitting laser with a heterogeneous tunnel junction, wherein the laser comprises, from top to bottom, 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.

[0008] Optionally, the type II heterojunction 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 p-type lightly doped Al x Ga 1-x As and n-type lightly doped Al x Ga 1-x As.

[0009] Optionally, the p-type lightly doped and n-type lightly doped Al x Ga 1-x AsAl x Ga 1-x The As component variation range is: x=0.2-0.4.

[0010] Optionally, the p-type heavily doped Al x Ga 1-x As y Sb 1-y Al x Ga 1-x As y Sb 1-y The component variation range is: x=0-0.2, y=0.8-1.

[0011] Optionally, the n-type heavily doped Al x Ga 1-x AsAl x Ga 1-x The As component variation range is: x=0-0.1.

[0012] Optionally, the p-type lightly doped and n-type lightly doped Al x Ga 1-x As doping concentration range is 5×10 17 cm -3 —2×10 18 cm-3 , thickness is 20-100nm.

[0013] Optionally, the p-type heavily doped Al x Ga 1-x As y Sb 1-y The doping concentration range is 5×10 19 cm -3 —1×10 20 cm -3 , with a thickness of 5-10nm.

[0014] Optionally, the n-type heavily doped Al x Ga 1-x The doping concentration of As is in the range of 8×10 18 cm -3 —3×10 19 cm -3 , thickness is 10-20nm.

[0015] The present invention also provides a method for preparing a multi-junction vertical cavity surface emitting laser with a heterogeneous tunnel junction, comprising the following steps:

[0016] S1, epitaxially growing an N-type Bragg reflector group, a second active region, a second oxide layer, a II-type heterojunction, a first active region, a first oxide layer, and a P-type Bragg reflector group on a substrate in sequence to obtain a first preform;

[0017] S2, manufacturing a P electrode on a side of the P-type Bragg reflector group of the first preform away from the first active region, and manufacturing an N electrode on a side of the substrate away from the N-type Bragg reflector group, to obtain a target laser.

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] 1. The present invention relates to a heterogeneous tunnel junction vertical cavity surface emitting laser and a preparation method thereof. By introducing a heterogeneous tunnel junction into the laser, a lower laser threshold and high power are ensured while reducing the series resistance and the inter-valence band absorption at the tunnel junction. The resistance of the tunnel junction of the present invention is about 40% smaller than that of the homogeneous tunnel junction, thereby realizing a high-performance multi-junction vertical cavity surface emitting laser and solving the problems of low power density, quantum efficiency and slope efficiency and high absorption loss of the existing vertical cavity surface emitting laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of a heterojunction vertical cavity surface emitting laser.

[0021] Figure 2Schematic diagram of the tunnel junction band structure of a heterojunction vertical cavity surface emitting laser.

[0022] Figure 3 Schematic diagram of optical and electrical performance testing in Experiment 1.

[0023] Reference numerals: 1-P electrode, 2-P type Bragg reflector group, 3-first oxide layer, 4-first active region, 5-II type heterojunction, 6-second oxide layer, 7-second active region, 8-N type Bragg reflector group, 9-substrate, 10-N electrode

[0024] In order to make the purpose, 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. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0025] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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. DETAILED DESCRIPTION

[0026] See also Figure 1 As shown, a multi-junction vertical cavity surface emitting laser with a heterojunction is shown, wherein the laser comprises, from top to bottom, a P electrode 1, a P-type Bragg reflector group 2, a first oxide layer 3, a first active region 4, a II-type heterojunction 5, a second oxide layer 6, a second active region 7, an N-type Bragg reflector group 8, a substrate 9, and an N electrode 10.

[0027] It can be understood that the heterojunction tunnel junction vertical cavity surface emitting laser involved in the present invention introduces a type II heterojunction 5 in the laser to ensure a lower laser threshold and high power while reducing the series resistance and the inter-valence band absorption at the tunnel junction, so that the resistance of the type II heterojunction 5 of the present invention is about 40% smaller than that of the homogeneous tunnel junction, thereby realizing a high-performance multi-junction vertical cavity surface emitting laser and solving the problems of low power density, quantum efficiency and slope efficiency, and high absorption loss of the existing vertical cavity surface emitting laser.

[0028] It should be understood that in a tunnel junction, on the one hand, in order to avoid light absorption, the tunnel junction material must be composed of a bandgap semiconductor with a larger energy than the laser wavelength; on the other hand, the tunneling probability increases as the bandgap of the semiconductor constituting the tunnel junction decreases, and it is difficult for short-wavelength vertical cavity surface emitting lasers to achieve a low-resistance tunnel junction. Therefore, it is difficult to achieve both low resistance and low light absorption at the same time.

[0029] The tunnel junction material of traditional near-infrared multi-junction vertical cavity surface emitting lasers (such as 905, 940 and 980nm) generally uses GaAs homojunction. However, for the 905nm multi-junction vertical cavity surface emitting laser, the fluorescence peak of the active area material at room temperature is around 890nm, and the corresponding photon energy is 1.393eV, while the band gap width of the intrinsic GaAs material at room temperature is 1.424eV, and the difference between the two is only 31meV. Considering the band gap shrinkage caused by the heavily doped band tail effect and carrier screening, as well as the red shift of the intrinsic absorption edge caused by the electric Franz-Keldysh effect, the GaAs homojunction may have intrinsic absorption of photons in this band. Therefore, the tunnel junction of the heterojunction is more superior.

[0030] Specifically, refer to the tunneling probability formula of type II junction: E geff ≡E gp -ΔE c =E gn -ΔE v (1) In formula (1), E gp and E gn represents the band gap energy between the p-side semiconductor and the n-side semiconductor, E geff represents the energy gap between the valence band edge on the p-side of the heterointerface and the conduction band edge on the n-side. geff Less than E gp and E gn , the tunneling probability of type II heterojunction is much greater than that of homojunction or type I tunnel junction.

[0031] Furthermore, in type II tunnel junction materials, due to E gp and E gn is greater than the laser wavelength energy, and E geff Less than the laser wavelength energy, therefore, light absorption can occur near the heterojunction. However, the transition from the valence band edge on the p-side of the heterojunction to the conduction band edge on the n-side requires the carrier function to penetrate the band gap, so its penetration probability is not high. In addition, in vertical cavity surface emitting lasers, the type II heterojunction is generally placed at the standing wave node. Therefore, the light absorption of the type II heterojunction is very small. This setting ensures a lower laser threshold and high power. At the same time, the resistance of the type II heterojunction is about 40% smaller than that of the homogeneous tunnel junction, which greatly reduces the resistance of the vertical cavity surface emitting laser.

[0032] Furthermore, in a multi-junction vertical cavity surface emitting laser with a heterojunction involved in the present invention, an oxide layer is provided on one side of the p-region of each active region. In addition to limiting the aperture of the light-emitting region, the oxide layer can also effectively suppress the leakage of electrons, thereby further improving the quantum efficiency of the device.

[0033] The type II heterojunction in the present invention comprises: adjacent p-type heavily doped Alx 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 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 the introduction of Al into the tunnel junction x Ga 1- x As y Sb 1-y With Al x Ga 1-x As two materials, make the tunnel junction have a heterostructure, where the light absorption is very small, so that a lower laser threshold, smaller resistance, larger output power and superior optoelectronic performance can be achieved here.

[0034] In some embodiments of the present invention, the p-type lightly doped and n-type lightly doped Al x Ga 1-x AsAl x Ga 1-x The As component variation range is: x=0.2-0.4.

[0035] Among them, the above-mentioned p-type lightly doped and n-type lightly doped Al x Ga 1-x AsAl x Ga 1-x The As composition variation range is preferably x=0.3.

[0036] In some embodiments of the present invention, the p-type heavily doped Al x Ga 1-x As y Sb 1-y Al x Ga 1-x As y Sb 1-y The component variation range is: x=0-0.2, y=0.8-1.

[0037] Among them, the above-mentioned p-type heavily doped Al x Ga 1-x As ySb 1-y Al x Ga 1-x As y Sb 1-y The composition variation range is preferably x=0.1, y=0.9.

[0038] In some embodiments of the present invention, the n-type heavily doped Al x Ga 1-x AsAl x Ga 1-x The As component variation range is: x=0-0.1.

[0039] Among them, the above n-type heavily doped Al x Ga 1-x AsAl x Ga 1-x The As composition variation range is preferably x=0.05.

[0040] In some embodiments of the present invention, the p-type lightly doped and n-type lightly doped Al x Ga 1-x As doping concentration range is 5×10 17 cm -3 —2×10 18 cm -3 , thickness is 20-100nm.

[0041] Among them, the above-mentioned p-type lightly doped and n-type lightly doped Al x Ga 1-x The As doping concentration range is 1×10 18 cm -3 , thickness is 60nm.

[0042] In some embodiments of the present invention, the p-type heavily doped Al x Ga 1-x As y Sb 1-y The doping concentration range is 5×10 19 cm -3 —1×10 20 cm -3 , with a thickness of 5-10nm.

[0043] Among them, the above-mentioned p-type heavily doped Al x Ga 1-x As y Sb 1-y The doping concentration range is preferably 1×10 20 cm -3 , with a thickness of 8nm.

[0044] In some embodiments of the present invention, the n-type heavily doped Al x Ga 1-x The doping concentration of As is in the range of 8×10 18 cm -3 —3×10 19 cm -3 , thickness is 10-20nm.

[0045] Among them, the above n-type heavily doped Al x Ga 1-x The doping concentration of As is preferably in the range of 8×10 18 , 1×10 19 , 3×10 19 cm -3 , thicknesses of 10, 12, 15, and 20 nm.

[0046] The present invention also provides a method for preparing a heterogeneous tunnel junction vertical cavity surface emitting laser, comprising the following steps:

[0047] S1, epitaxially growing an N-type Bragg reflector group 8, a second active region 7, a second oxide layer 6, a II-type heterojunction 5, a first active region 4, a first oxide layer 3, and a P-type Bragg reflector group 2 on a substrate 9 in sequence to obtain a first preform;

[0048] S2, manufacturing a P electrode 1 on a side of the P-type Bragg reflector group 2 of the first preform away from the first active region 4, and manufacturing an N electrode 10 on a side of the substrate 9 away from the N-type Bragg reflector group 8, to obtain a target laser.

[0049] In the present invention, a GaAs substrate is preferred.

[0050] The P electrode 1 and the N electrode 10 of the present invention are any one of gold, copper, graphite, silver or tin.

[0051] It should be noted that in the specific epitaxial process, there is a buffer layer between the layers involved, such as the P-type Bragg reflector group 2, the first oxide layer 3, the first active area 4, the type II heterojunction 5, the second oxide layer 6, the second active area 7, and the N-type Bragg reflector group 8. The parameters are adjusted according to the actual preparation requirements to perform epitaxial growth on each buffer layer to meet the actual needs.

[0052] In some embodiments of the present invention, the epitaxial method may be metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE) to perform epitaxy on each layer.

[0053] Example 1

[0054] A multi-junction vertical cavity surface emitting laser with a heterogeneous tunnel junction, wherein the laser comprises, from top to bottom, 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.

[0055] In this embodiment, the type II heterojunction 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 p-type lightly doped Al 0.3 Ga 0.7 As and n-type lightly doped Al 0.2 Ga 0.7 As.

[0056] Among them, p-type lightly doped Al 0.3 Ga 0.7 As and n-type lightly doped Al 0.2 Ga 0.7 The doping concentration of As is in the range of 5×10 17 cm -3 , thickness is 20nm; p-type heavily doped Al 0.15 Ga 0.85 As 0.95 Sb 0.05 The doping concentration range is 5×10 19 cm -3 , thickness is 6nm; n-type heavily doped Al 0.1 Ga 0.9 The doping concentration of As is in the range of 8×10 18 cm -3 , with a thickness of 11nm.

[0057] Example 2

[0058] A multi-junction vertical cavity surface emitting laser with a heterogeneous tunnel junction, wherein the laser comprises, from top to bottom, 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.

[0059] In this embodiment, the type II heterojunction includes: adjacent p-type heavily doped Al0.2 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 p-type lightly doped Al 0.2 Ga 0.8 As and n-type lightly doped Al 0.2 Ga 0.8 As.

[0060] Among them, p-type lightly doped Al 0.2 Ga 0.8 As and n-type lightly doped Al 0.2 Ga 0.8 The As doping concentration range is 1×10 18 cm -3 , thickness is 60nm; p-type heavily doped Al 0.2 Ga 0.8 As 0.9 Sb 0.1 The doping concentration range is 0.5×10 20 cm -3 , thickness is 8nm; and n-type heavily doped Al 0.1 Ga 0.9 The doping concentration of As is in the range of 2×10 19 cm -3 , with a thickness of 15nm.

[0061] Example 3

[0062] A multi-junction vertical cavity surface emitting laser with a heterogeneous tunnel junction, wherein the laser comprises, from top to bottom, 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.

[0063] In this embodiment, the type II heterojunction 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 Sb0.1 and n-type heavily doped Al 0.1 Ga 0.9 Both sides of As are p-type lightly doped Al 0.2 Ga 0.8 As and n-type lightly doped Al 0.2 Ga 0.8 As.

[0064] Among them, p-type lightly doped Al 0.2 Ga 0.8 As and n-type lightly doped Al 0.2 Ga 0.8 As doping concentration range is 2×10 18 cm -3 , thickness is 100nm; p-type heavily doped Al 0.15 Ga 0.85 As 0.95 Sb 0.05 The doping concentration range is 1×10 20 cm -3 , thickness is 10nm; and n-type heavily doped Al 0.1 Ga 0.9 The doping concentration of As is in the range of 3×10 19 cm -3 , thickness is 20nm.

[0065] Furthermore, in order to verify the optical and electrical performances of the emitting laser involved in the present invention, the following test examples were carried out.

[0066] Test example: Checking the optical and electrical performance of the laser emitter

[0067] 1.1 Experimental design

[0068] The experiment set up two treatment groups, the experimental group was the Al involved in Example 1 0.1 Ga 0.9 As / Al 0.15 Ga 0.85 As 0.95 Sb 0.05 The optical and electrical performances of the triple-junction vertical cavity surface emitting laser with type II heterojunction and the control group with ordinary homogeneous tunnel junction vertical cavity surface emitting laser were tested under the same experimental conditions.

[0069] Test results see Figure 3 , where the dashed line represents the control group (normal GaAs homogeneous tunnel junction vertical cavity surface emitting laser), and the solid line represents the experimental group (Al 0.1 Ga 0.9 As / Al 0.15 Ga 0.85 As0.95 Sb 0.05 Type II heterojunction vertical cavity surface emitting laser).

[0070] After testing, the current-power curve representing the optical performance and the current-voltage curve representing the electrical performance were obtained.

[0071] 1.2 Results Analysis

[0072] See also Figure 3 From the current-power curve, we can see that in terms of optical performance, the current lasing threshold of the experimental group is 1.1mA, while the current lasing threshold of the control group is 1.2mA. It can be seen that the current lasing thresholds of the two groups are not much different. This is because the use of type II heterojunction Al x Ga 1-x As / Al x Ga 1-x As y Sb 1-y There is no increase in absorption loss. It can be seen that compared with the control group, the differential resistance and oblique line efficiency of the experimental group are better when the lasing threshold is kept unchanged. Therefore, the heterojunction tunnel junction vertical cavity surface emitting laser of Example 1 has a higher photoelectric conversion efficiency.

[0073] Referring to the current-voltage curve, in terms of electrical performance, the curve of the experimental group is steeper, that is, the differential resistance of the experimental group is smaller than that of the control group. x Ga 1-x As / Al x Ga 1-x As y Sb 1-y It has a shorter tunneling distance, which increases the tunneling probability of electrons and thus reduces the differential resistance.

[0074] Combining the two groups of curves, compared with the control group, the experimental group has better differential resistance and oblique line efficiency while ensuring that the lasing threshold remains unchanged, and has a higher photoelectric conversion efficiency.

[0075] In summary, the multi-junction vertical cavity surface emitting laser with a heterogeneous tunnel junction involved in the present invention introduces a heterogeneous tunnel junction in the laser to ensure a lower laser threshold and high power while reducing the series resistance and the absorption between the valence bands at the tunnel junction, so that the resistance of the tunnel junction of the present invention is about 40% smaller than that of the homogeneous tunnel junction, thereby realizing a high-performance multi-junction vertical cavity surface emitting laser and solving the problems of low power density, quantum efficiency and slope efficiency, and high absorption loss of the existing vertical cavity surface emitting lasers.

[0076] The above embodiment is only one implementation of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A multi-junction vertical cavity surface emitting laser with heterojunction tunnel junction, characterized in that: The laser comprises, from top to bottom, 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; the II-type heterogeneous 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 p-type lightly doped Al x Ga 1-x As and n-type lightly doped Al x Ga 1-x As.

2. The heterojunction multi-junction vertical cavity surface emitting laser according to claim 1, characterized in that: The p-type lightly doped and n-type lightly doped Al x Ga 1-x AsAl x Ga 1-x The As component variation range is: x=0.2-0.

4.

3. The heterojunction multi-junction vertical cavity surface emitting laser according to claim 1, characterized in that: The p-type heavily doped Al x Ga 1-x As y Sb 1-y Al x Ga 1-x As y Sb 1-y The component variation range is: x=0-0.2, y=0.8-1.

4. The heterojunction multi-junction vertical cavity surface emitting laser according to claim 1, characterized in that: The n-type heavily doped Al x Ga 1-x AsAl x Ga 1-x The As component variation range is: x=0-0.

1.

5. The heterojunction multi-junction vertical cavity surface emitting laser according to claim 2, characterized in that: The p-type lightly doped and n-type lightly doped Al x Ga 1-x As doping concentration range is 5×10 17 cm -3 —2×10 18 cm -3 , thickness is 20-100nm.

6. The heterojunction multi-junction vertical cavity surface emitting laser according to claim 3, characterized in that: The p-type heavily doped Al x Ga 1-x As y Sb 1-y The doping concentration range is 5×10 19 cm -3 —1×10 20 cm -3 , with a thickness of 5-10nm.

7. The heterojunction multi-junction vertical cavity surface emitting laser according to claim 4, characterized in that: The n-type heavily doped Al x Ga 1-x The doping concentration of As is in the range of 8×10 18 cm -3 —3×10 19 cm -3 , with a thickness of 10-20nm.

8. The method for preparing a multi-junction vertical cavity surface emitting laser with heterojunction tunnel junction according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, epitaxially growing an N-type Bragg reflector group, a second active region, a second oxide layer, a II-type heterojunction, a first active region, a first oxide layer, and a P-type Bragg reflector group on a substrate in sequence to obtain a first preform; S2, manufacturing a P electrode on a side of the P-type Bragg reflector group of the first preform away from the first active region, and manufacturing an N electrode on a side of the substrate away from the N-type Bragg reflector group, to obtain a target laser.

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