A wafer fusion integrated multi-junction long wavelength surface emitting laser and its manufacturing method

Abstract

The present invention discloses a wafer fusion integrated multi-junction long wavelength surface emitting laser and a manufacturing method, including: a surface emitting laser VCSEL structure and a modulator EOM structure; the surface emitting laser VCSEL structure includes a GaAs base substrate, a GaAs buffer layer, a first N-type doped DBR, a resonant cavity, a buried tunnel junction, a fill layer, and a P-type doped DBR from bottom to top; the modulator EOM structure includes a P-type doped DBR, a first waveguide layer, an absorption layer, a second waveguide layer, and a second N-type doped DBR from bottom to top; the surface emitting laser VCSEL structure and the modulator EOM structure share a P-type doped DBR. The present invention can significantly improve the heat dissipation problem, reduce the divergence angle of the emitted light, and improve the output beam quality.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor laser optoelectronic technology, and in particular relates to a wafer fusion integrated multi-junction long wavelength surface emitting laser and a manufacturing method thereof. Background Art

[0002] With the rapid development of the data communication era, Vertical Cavity Surface Emitting Laser (VCSEL) chips are widely used in optical communication and consumer fields due to their excellent characteristics, such as small size, circular light spot output, low operating threshold current, high coupling efficiency, and easy integration. VCSEL chips have good economy, practicality and reliability, which has brought great convenience to information exchange in all walks of life. As the amount of data increases, higher requirements are placed on the rate and quality of data transmission. At present, VCSEL chips used for information mostly use direct modulation to transmit signals, and the transmission bandwidth limits the improvement of transmission performance. Integrated laser structure is a possible solution to further increase bandwidth.

[0003] The current laser integrated chips include: edge-emitting integrated chips integrated with DFB and modulation units, GaAs-based short-wavelength integrated surface-emitting laser chips, including direct formation of VCSEL and EOM. VCSEL and EOM use PDBR to realize the resonant cavity structure of VCSEL and enhance the light absorption of EOM. It is generally a structure of N DBR-active area-oxidation restriction layer-PDBR-absorption layer-N DBR. In this structure, the current light field of the VCSEL part is restricted by an oxidation restriction layer, which is not suitable for long-wavelength integrated surface-emitting laser chips. In order to ensure the stable output of the VCSEL unit, relief, microlens, grating and other structures are added on the top of the EOM to optimize the output beam quality. However, all of the above are short-wavelength integrated surface-emitting laser chips based on GaAs. There are fewer references to integrated surface-emitting laser chips in the long wavelength field, and the output beam quality, power conversion efficiency and output power of the device are likely to be further optimized and improved. Summary of the invention

[0004] To solve the above problems, the present invention provides the following solution: a wafer fusion integrated multi-junction long wavelength surface emitting laser and a manufacturing method. Among them, a wafer fusion integrated multi-junction long wavelength surface emitting laser includes: a surface emitting laser VCSEL structure and a modulator EOM structure;

[0005] The surface emitting laser VCSEL structure includes, from bottom to top, a GaAs-based substrate, a GaAs buffer layer, a first N-type doped DBR, a resonant cavity, a buried tunnel junction, a filling layer, and a P-type doped DBR;

[0006] The modulator EOM structure includes, from bottom to top, a P-type doped DBR, a first waveguide layer, an absorption layer, a second waveguide layer, and a second N-type doped DBR;

[0007] The surface emitting laser VCSEL structure and the modulator EOM structure share a P-type doped DBR.

[0008] Preferably, the laser further comprises a contact layer, a first annular electrode, and a second annular electrode;

[0009] The contact layer is disposed inside the P-type doped DBR and on the top of the second N-type doped DBR;

[0010] The first annular electrode and the second annular electrode are respectively arranged on the upper surface of the P-type doped DBR and the upper surface of the second N-type doped DBR.

[0011] Preferably, the first N-type doped DBR, the P-type doped DBR and the second N-type doped DBR are stacked and bonded Al(Ga)As / GaAs DBR structures with a quarter target wavelength optical thickness, and a thickness of n times the half target wavelength optical thickness.

[0012] Preferably, the GaAs buffer layer is connected to a first N-type doped DBR, and the first N-type doped DBR is connected to a resonant cavity;

[0013] The resonant cavity is an InP-based optical resonant cavity structure, and a buried tunnel junction wrapped by a filling layer is connected to the InP optical resonant cavity structure;

[0014] The filling layer is made of InP material, and a GaAs-based P-type doped DBR is connected to the filling layer;

[0015] The buried tunnel junction is made of N-type and P-type heavily doped InGaAs material, has an elliptical shape, and a size of 20-70 μm;

[0016] The resonant cavity, buried tunnel junction and filling layer constitute an InP-based system for wafer fusion.

[0017] Preferably, the P-type doped DBR is sequentially connected to a first waveguide layer, an absorption layer and a second waveguide layer;

[0018] The second waveguide layer is connected to a second N-type doped DBR;

[0019] The first waveguide layer and the second waveguide layer are Si-doped Al y Ga 1-y As (0.4≤y≤0.5), thickness 60-80nm;

[0020] The first waveguide layer and the second waveguide layer are respectively doped with N-type and P-type to form a PN junction, and an absorption layer is formed between the PN junctions;

[0021] The absorption layer includes a pair of Al z Ga 1-z The quantum well of As / GaAs (0.3≤z≤0.5) has a thickness of 8-30nm, and the thickness of the absorption layer is half the wavelength of the target wavelength.

[0022] Preferably, the modulator EOM structure realizes light intensity modulation of the opposite-emitting laser VCSEL structure based on the bias formed by the reflectivity deviation between the second N-type doped DBR and the first N-type doped DBR and the P-type doped DBR; by modulating the bias voltage of the modulator EOM structure, the absorption state of the absorption layer is directly affected, and then the overall reflectivity of the second N-type doped DBR is controlled, thereby indirectly realizing high-speed modulation of the output light intensity of the opposite-emitting laser VCSEL structure.

[0023] Preferably, the resonant cavity adopts a multi-active region design, and the multi-active region is an active region of multiple groups of short-period superlattice structures connected based on buried tunnel junctions, and the multi-active region includes an active region and a tunnel junction of an ultra-short period InGaAs / InAlGaAs superlattice.

[0024] Preferably, the active region of the ultra-short period InGaAs / InAlGaAs superlattice is N-type heavily doped and P-type heavily doped InGaAlAs, and the P-type doped layer is thicker than the N-type doped layer;

[0025] The active region has an optical thickness of an integral multiple of a half wavelength, and the superlattice layer is placed at the crest of the standing wave according to the target wavelength, and the elliptical buried tunnel junction is placed at the node of the standing wave.

[0026] The present invention also provides a method for manufacturing a wafer fusion integrated multi-junction long-wavelength surface emitting laser, comprising: growing an elliptical cylindrical epitaxial structure using a molecular beam epitaxy or chemical vapor deposition method according to the laser structure, growing a first N-type doped DBR and a P-type doped DBR elliptical epitaxial structure including a contact layer on a GaAs-based substrate, and sequentially growing a first waveguide layer, an absorption layer, a second waveguide layer, and a second N-type doped DBR epitaxial structure on the P-type doped DBR including the contact layer;

[0027] A multi-junction cascaded superlattice optical resonant cavity and an epitaxial structure of a tunnel junction are sequentially grown on an InP substrate, and then an elliptical tunnel junction is etched using inductively coupled plasma, and an InP filling layer is secondary epitaxially grown to form a buried tunnel junction; the InP wafer is fused with a first N-type doped DBR wafer grown on a GaAs-based substrate, and the formed new structure is etched by inductively coupled plasma to form a first table;

[0028] The new structure is then fused with a P-doped DBR wafer, and then inductively coupled plasma etching is performed to obtain the second and third mesas. After that, metallization treatment is performed on the second and third mesas to obtain a complete laser structure.

[0029] Preferably, the process of performing metallization treatment on the second table and the third table includes:

[0030] Metal ring electrodes are electroplated on the second table and the third table. The first elliptical cylinder, the second elliptical cylinder and the third elliptical cylinder corresponding to the first table, the second table and the third table are coaxially arranged.

[0031] Compared with the prior art, the present invention has the following advantages and technical effects:

[0032] The present invention is aimed at long-wavelength integrated surface-emitting chips. Firstly, wafer fusion is used to combine the InP-based optical cavity structure with the Al(Ga)As / GaAs DBR structure to achieve the advantages of GaAs-based materials and InP-based materials. Compared with the hybrid cavity VCSEL using dielectric DBR commonly used in long-wavelength VCSELs, the heat dissipation problem can be significantly improved.

[0033] The present invention adopts a multi-active region design for the InP-based optical cavity, which is based on multiple groups of short-period superlattice structure active regions connected by tunnel junctions. The multi-active region design is used to improve conversion efficiency and output power. At the same time, the multiple active regions connected by tunnel junctions form an expansion of the cavity, which lengthens the cavity length, can reduce the divergence angle of the emitted light, and improve the output beam quality.

[0034] The multi-active region structure of the present invention adopts a short-period superlattice structure. The active region based on the short-period superlattice can further increase the mode gain compared with the quantum well structure. Increasing the differential gain of the active region can increase the resonant frequency and increase the bandwidth. Usually, InAlGaAs-InP quantum wells are used as active region materials for long-wavelength band devices such as InP-based VCSELs and hybrid short-cavity VCSELs. Compared with the active region of the short-wave band, the Al content of the active region of the long-wavelength VCSEL must be significantly increased, which will lead to an increase in the non-radiative Shockley-Read-Hall (SRH) recombination rate and threshold current. The active region based on the short-period superlattice can avoid these problems. The mutual tunneling of charge carriers in the adjacent layer caused by the quantization splitting forms a subband. At the same time, the state density function of the charge carriers in the superlattice structure is close to the step-like behavior of the traditional quantum well, which further increases the longitudinal optical confinement factor. The above design can simultaneously achieve the increase of mode gain and the reduction of threshold current. The active region (InGaAs / InAlGaAs) based on short-period superlattice can achieve high modal gain and low gain compression factor.

[0035] The elliptical buried tunnel junction structure of the present invention, on the one hand, realizes the function of current and light field limitation as a buried tunnel junction, and on the other hand, the elliptical structure optimizes the polarization phenomenon caused by the change of device structure, enhances mode stability, and prevents mode hopping. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0037] Figure 1 Schematic diagram of the cross-sectional structure of a laser according to an embodiment of the present invention;

[0038] Figure 2 A cross-sectional view of a multi-junction cascade active region of a laser according to an embodiment of the present invention;

[0039] Figure 3 is a top view of a laser structure according to an embodiment of the present invention;

[0040] Among them, 101, buried tunnel junction; 102, contact layer; 103, first annular electrode; 104, second annular electrode; 111, first elliptical table; 112, second elliptical table; 113, third elliptical table;

[0041] 201, GaAs substrate; 202, GaAs buffer layer; 203, first N-type doped DBR; 204, resonant cavity; 205, filling layer; 206, P-type doped DBR; 207, first waveguide layer; 208, absorption layer; 209, second waveguide layer; 210, second N-type doped DBR;

[0042] 301. Active region of ultra-short period InGaAs / InAlGaAs superlattice; 302. Buried tunnel junction; 303. Active region of ultra-short period InGaAs / InAlGaAs superlattice; 304. Tunnel junction; 305. Active region of ultra-short period InGaAs / InAlGaAs superlattice. DETAILED DESCRIPTION

[0043] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0044] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0045] The present invention combines the EOM structure and the long wavelength surface emitting laser VCSEL structure together through an integrated method, and utilizes the EOM unit to modulate the light intensity of the VCSEL unit based on the reflectivity deviation of the top reflector and the bottom reflector. By modulating the bias voltage of the EOM unit, the absorption state of the absorption layer is affected, and then the overall reflectivity of the top reflector is controlled, thereby indirectly achieving high-speed modulation of the VCSEL output light intensity. This structure is used to improve the modulation performance.

[0046] The InP-based optical cavity structure is combined with the Al(Ga)As / GaAs DBR structure through the wafer fusion method, combining the advantages of GaAs-based materials and InP-based material systems to significantly improve the heat dissipation problem.

[0047] By designing the active area, multiple groups of short-period superlattice structures are connected by tunnel junctions to improve conversion efficiency and output power, increase differential gain and thus bandwidth, lengthen the cavity length and thus reduce divergence angle to improve beam quality; by limiting the current and light field of the device through an elliptical buried tunnel junction at the top of the active area, the mode stability of the device can be improved.

[0048] A short-period superlattice structure is used in the multi-active region structure. The active region based on the short-period superlattice will further increase the mode gain compared to the quantum well structure. Increasing the differential gain of the active region can increase the resonant frequency and bandwidth. Usually, InAlGaAs-InP quantum wells are used as the active region materials for long-wavelength band devices such as InP-based VCSELs and hybrid short-cavity VCSELs. Compared with the active region of the short-wave band, the Al content of the active region of the long-wavelength VCSEL must be significantly increased, which will lead to an increase in the non-radiative Shockley-Read-Hall (SRH) recombination rate and threshold current. The active region based on the short-period superlattice can avoid these problems. The mutual tunneling of charge carriers in the adjacent layers caused by the quantization splitting forms subbands. At the same time, the state density function of the charge carriers in the superlattice structure is close to the step-like behavior of the traditional quantum well, which further increases the longitudinal optical confinement factor. The increase in mode gain and the reduction in threshold current can be achieved simultaneously through design. The active region based on short-period InGaAs / InAlGaAs superlattice can achieve high modal gain and low gain compression factor.

[0049] Based on this, this embodiment proposes a wafer fusion integrated multi-junction long wavelength surface emitting laser structure and a manufacturing method.

[0050] like Figure 1 As shown, the present invention provides a wafer fusion integrated multi-junction long wavelength surface emitting laser, comprising:

[0051] Surface emitting laser VCSEL structure and modulator EOM structure;

[0052] The surface emitting laser VCSEL structure includes, from bottom to top, a GaAs base substrate 201, a GaAs buffer layer 202, a first N-type doped DBR 203, a resonant cavity 204, a buried tunnel junction 101, a filling layer 205, and a P-type doped DBR 206;

[0053] The modulator EOM structure includes, from bottom to top, a P-type doped DBR 206, a first waveguide layer 207, an absorption layer 208, a second waveguide layer 209, and a second N-type doped DBR 210;

[0054] The surface emitting laser VCSEL structure and the modulator EOM structure share the P-type doped DBR 206 .

[0055] Furthermore, the laser further includes a contact layer 102, a first annular electrode 103, and a second annular electrode 104;

[0056] The contact layer 102 is disposed inside the P-type doped DBR and on the top of the second N-type doped DBR to be externally connected to an electrode.

[0057] The first annular electrode 103 and the second annular electrode 104 are disposed on the upper surface of the P-type doped DBR 206 and the upper surface of the second N-type doped DBR 210 respectively.

[0058] Furthermore, the first N-type doped DBR 203, the P-type doped DBR 206, and the second N-type doped DBR

[0059] 210 is a stacked and bonded Al(Ga)As / GaAs DBR structure with a quarter target wavelength optical thickness, and a thickness of n times the half target wavelength optical thickness. x Ga 1-x In As, x≤0.92, and the DBR logarithm is not limited to the DBR logarithm shown in the figure.

[0060] Furthermore, the GaAs buffer layer 202 is connected to the first N-type doped DBR 203, and the first N-type doped DBR 203 is connected to the resonant cavity 204, so as to combine the advantages of GaAs-based materials and InP-based materials and significantly improve the heat dissipation problem.

[0061] The resonant cavity 204 is an InP-based optical resonant cavity structure, and the buried tunnel junction 101 wrapped by the filling layer 205 is connected to the InP optical resonant cavity structure;

[0062] The filling layer 205 is made of InP material to improve the heat dissipation effect of the device, and the filling layer 205 is connected to a GaAs-based P-type doped DBR 206;

[0063] The buried tunnel junction 101 is made of N-type and P-type heavily doped InGaAs material, has an elliptical shape, and a size of 20-70 μm;

[0064] The resonant cavity 204, the buried tunnel junction 101, and the filling layer 205 constitute an InP-based system for wafer fusion.

[0065] Furthermore, the P-type doped DBR 206 is sequentially connected to a first waveguide layer 207, an absorption layer 208 and a second waveguide layer 209;

[0066] The second waveguide layer 209 is connected to the second N-type doped DBR 210;

[0067] The first waveguide layer 207 and the second waveguide layer 209 are Si-doped Al y Ga 1-y As (0.4≤y≤0.5), thickness 60-80nm;

[0068] The first waveguide layer 207 and the second waveguide layer 209 are respectively doped with N-type and P-type to form a PN junction, and an absorption layer 208 is formed between the PN junctions;

[0069] The absorption layer 208 includes a pair of Al z Ga 1-z The quantum well of As / GaAs (0.3≤z≤0.5) has a thickness of 8-30 nm, and the thickness of the absorption layer 208 is approximately half the wavelength of the target wavelength.

[0070] Furthermore, the modulator EOM structure realizes light intensity modulation of the opposite-emitting laser VCSEL structure based on the bias voltage formed by the reflectivity deviation between the top reflector (the second N-type doped DBR 210) and the bottom reflector (the first N-type doped DBR 203 and the P-type doped DBR 206); by modulating the bias voltage of the modulator EOM structure, the absorption state of the absorption layer is directly affected, thereby controlling the overall reflectivity of the second N-type doped DBR, and indirectly realizing high-speed modulation of the output light intensity of the opposite-emitting laser VCSEL structure.

[0071] Furthermore, the laser structure of the present invention uses an InP-based optical resonant cavity to achieve long-wavelength beam lasing. The resonant cavity adopts a multi-active region design, and the multi-active region is an active region of multiple groups of short-period superlattice structures connected based on buried tunnel junctions. The multi-active region design is used to improve conversion efficiency and output power. At the same time, the multiple active regions connected by the tunnel junction form an expansion of the cavity, which lengthens the cavity length, can reduce the divergence angle of the emitted light, and improve the output beam quality.

[0072] like Figure 2As shown, the multiple active regions include an active region 301 of an ultra-short period InGaAs / InAlGaAs superlattice, an active region 303 of an ultra-short period InGaAs / InAlGaAs superlattice, an active region 305 of an ultra-short period InGaAs / InAlGaAs superlattice, and tunnel junctions 302 and 304.

[0073] Further, the active region of the ultra-short period InGaAs / InAlGaAs superlattice is N-type heavily doped and P-type heavily doped InGaAlAs, and the P-type doped layer is thicker than the N-type doped layer;

[0074] Each active region has an integral multiple of half-wavelength optical thickness, and the superlattice layer is placed at the crest of the standing wave according to the target wavelength, and the elliptical buried tunnel junction is placed at the node of the standing wave to achieve the purpose of large gain and small absorption loss. The figure shows only three superlattice active regions, and the multi-junction cascade active regions of the present invention are not limited to three, and can also be two, four, or more than or equal to two multi-junction cascade active regions.

[0075] The present invention proposes a wafer-fused integrated multi-junction long-wavelength surface-emitting laser structure for vertical cavity surface-emitting laser chips. The structure uses a wafer fusion method to combine an InP-based optical cavity structure with a DBR structure Al(Ga)As / GaAs; and a multi-active region design is performed, and an active region based on a tunnel junction connecting multiple groups of short-period superlattice structures is designed. The design is used to improve conversion efficiency and output power, and it will further increase the mode gain compared to the quantum well structure, and increasing the differential gain of the active region can increase the resonant frequency and bandwidth. At the same time, the multiple active regions connected by the tunnel junction form an expansion of the cavity, which lengthens the cavity length, can reduce the divergence angle of the emitted light, and improve the output beam quality; the elliptical buried tunnel junction of the structure realizes the functions of current and light field limitation while enhancing the mode stability and preventing the occurrence of mode hopping.

[0076] Embodiment 2

[0077] The present invention also provides a method for manufacturing a wafer fusion integrated multi-junction long wavelength surface emitting laser, comprising: growing an elliptical cylindrical epitaxial structure using a molecular beam epitaxy or chemical vapor deposition method according to the above laser structure, growing a first N-type doped DBR 203 and a P-type doped DBR 206 elliptical epitaxial structure including a contact layer 102 on a GaAs-based substrate 201, and sequentially growing a first waveguide layer 207, an absorption layer 208, a second waveguide layer 209, and a second N-type doped DBR 210 epitaxial structure on the P-type doped DBR 206 including the contact layer 102;

[0078] On an InP substrate, a multi-junction cascaded superlattice optical resonant cavity and an epitaxial structure of a tunnel junction are sequentially grown, and then an elliptical tunnel junction is etched using inductively coupled plasma, and an InP filling layer is secondary epitaxially grown to form a buried tunnel junction 101 at the same time; the InP wafer is merged with a first N-type doped DBR 203 wafer grown on a GaAs-based substrate 201, and the formed new structure is etched by inductively coupled plasma to form a first table;

[0079] The new structure is then fused with a P-doped DBR wafer, and then the second and third mesas are obtained by inductively coupled plasma etching, and then metallization is performed on the second and third mesas, that is, metal ring electrodes are electroplated on the mesas according to the above structure to obtain a complete laser structure.

[0080] like Figure 3 As shown, the first elliptical table 111, the second elliptical table 112, and the third elliptical table 113 corresponding to the first elliptical cylinder, the second elliptical cylinder, and the third elliptical cylinder are coaxially arranged to facilitate the heat dissipation of the laser. The shaded parts are annular electrodes, which are the first annular electrode 103 and the second annular electrode 104. Finally, a wafer fusion integrated multi-junction long wavelength laser with a surface emitting laser VCSEL structure and a modulator EOM structure is obtained.

[0081] The present invention proposes a wafer fusion integrated multi-junction long wavelength surface emitting laser structure and a manufacturing method for a vertical cavity surface emitting laser chip, which combines EOM and VCSEL together through integration. For the long wavelength integrated surface emitting chip, the InP-based optical cavity structure and the Al(Ga)As / GaAs DBR structure are combined by the wafer fusion method, so as to combine the advantages of GaAs-based materials and InP-based materials, and significantly improve the heat dissipation problem.

[0082] The present invention adopts a multi-active region design for the InP-based optical cavity, and designs an active region based on a tunnel junction connecting multiple groups of short-period superlattice structures. This design is used to improve conversion efficiency and output power, and it will further increase the mode gain compared to the quantum well structure, and increasing the differential gain of the active region can increase the resonance frequency and bandwidth. At the same time, the multiple active regions connected by the tunnel junction form an expansion of the cavity, which lengthens the cavity length, can reduce the divergence angle of the emitted light, and improve the output beam quality.

[0083] The laser structure of the present invention adopts an elliptical buried tunnel junction structure. On the one hand, as a buried tunnel junction, it realizes the function of current and light field limitation. On the other hand, the elliptical structure optimizes the polarization phenomenon caused by the change of device structure, enhances mode stability and prevents mode hopping.

[0084] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A wafer fusion integrated multi-junction long wavelength surface emitting laser, characterized in that: include: Surface emitting laser VCSEL structure and modulator EOM structure; The surface emitting laser VCSEL structure includes, from bottom to top, a GaAs-based substrate, a GaAs buffer layer, a first N-type doped DBR, a resonant cavity, a buried tunnel junction, a filling layer, and a P-type doped DBR; The modulator EOM structure includes, from bottom to top, a P-type doped DBR, a first waveguide layer, an absorption layer, a second waveguide layer, and a second N-type doped DBR; The surface emitting laser VCSEL structure and the modulator EOM structure share a P-type doped DBR; The GaAs buffer layer is connected to a first N-type doped DBR, and the first N-type doped DBR is connected to a resonant cavity; The resonant cavity is an InP-based optical resonant cavity structure, and a buried tunnel junction wrapped by a filling layer is connected to the InP optical resonant cavity structure; The filling layer is made of InP material, and a GaAs-based P-type doped DBR is connected to the filling layer; The buried tunnel junction is made of N-type and P-type heavily doped InGaAs material, has an elliptical shape, and a size of 20-70 μm; The resonant cavity, buried tunnel junction, and fill layer constitute an InP-based system for wafer fusion; The P-type doped DBR is connected in sequence to a first waveguide layer, an absorption layer, and a second waveguide layer; The second waveguide layer is connected to a second N-type doped DBR; The first waveguide layer and the second waveguide layer are Si-doped Al y Ga 1-y As (0.4≤y≤0.5), thickness 60-80nm; The first waveguide layer and the second waveguide layer are respectively doped with N-type and P-type to form a PN junction, and an absorption layer is formed between the PN junctions; The absorption layer includes a pair of Al z Ga 1-z The quantum well of As / GaAs (0.3≤z≤0.5) has a thickness of 8-30nm, and the thickness of the absorption layer is half the wavelength of the target wavelength.

2. The wafer fusion integrated multi-junction long wavelength surface emitting laser according to claim 1, characterized in that: The laser also includes a contact layer, a first annular electrode, and a second annular electrode; The contact layer is disposed inside the P-type doped DBR and on the top of the second N-type doped DBR; The first annular electrode and the second annular electrode are respectively arranged on the upper surface of the P-type doped DBR and the upper surface of the second N-type doped DBR.

3. The wafer fusion integrated multi-junction long wavelength surface emitting laser according to claim 1, characterized in that: The first N-type doped DBR, the P-type doped DBR and the second N-type doped DBR are stacked and fixed Al(Ga)As / GaAs DBR structures with a quarter of the target wavelength optical thickness, and the thickness is n times the half target wavelength optical thickness.

4. The wafer fusion integrated multi-junction long wavelength surface emitting laser according to claim 1, characterized in that: The modulator EOM structure realizes light intensity modulation of the surface-emitting laser VCSEL structure based on the bias voltage formed by the reflectivity deviation between the second N-type doped DBR and the first N-type doped DBR and the P-type doped DBR; By modulating the bias voltage of the modulator EOM structure, the absorption state of the absorption layer is directly affected, thereby controlling the overall reflectivity of the second N-type doped DBR, and indirectly achieving high-speed modulation of the output light intensity of the surface-emitting laser VCSEL structure.

5. The wafer fusion integrated multi-junction long wavelength surface emitting laser according to claim 1, characterized in that: The resonant cavity adopts a multi-active region design, wherein the multi-active region is an active region of multiple groups of short-period superlattice structures connected based on buried tunnel junctions, and the multi-active region includes an active region and a tunnel junction of an ultra-short-period InGaAs / InAlGaAs superlattice.

6. The wafer fusion integrated multi-junction long wavelength surface emitting laser according to claim 5, characterized in that: The active region of the ultra-short period InGaAs / InAlGaAs superlattice is N-type heavily doped and P-type heavily doped InGaAlAs, and the P-type doped layer is thicker than the N-type doped layer; The active region has an optical thickness of an integral multiple of a half wavelength, and the superlattice layer is placed at the crest of the standing wave according to the target wavelength, and the elliptical buried tunnel junction is placed at the node of the standing wave.

7. A method for manufacturing a wafer fusion integrated multi-junction long wavelength surface emitting laser, characterized in that: include: According to the laser structure, an elliptical cylindrical epitaxial structure is grown by molecular beam epitaxy or chemical vapor deposition, and a first N-type doped DBR and a P-type doped DBR elliptical epitaxial structure including a contact layer are grown on a GaAs-based substrate, and a first waveguide layer, an absorption layer, a second waveguide layer, and a second N-type doped DBR epitaxial structure are grown in sequence on the P-type doped DBR including the contact layer; A multi-junction cascaded superlattice optical resonant cavity and an epitaxial structure of a tunnel junction are sequentially grown on an InP substrate, and then an elliptical tunnel junction is etched using inductively coupled plasma, and an InP filling layer is secondary epitaxially grown to form a buried tunnel junction; the InP wafer is fused with a first N-type doped DBR wafer grown on a GaAs-based substrate, and the formed new structure is etched by inductively coupled plasma to form a first table; The new structure is then fused with a P-doped DBR wafer, and then inductively coupled plasma etching is performed to obtain the second and third mesas. After that, metallization treatment is performed on the second and third mesas to obtain a complete laser structure.

8. The method for manufacturing a wafer fusion integrated multi-junction long wavelength surface emitting laser according to claim 7, characterized in that: The process of metallization on the second and third surfaces includes: Metal ring electrodes are electroplated on the second table and the third table. The first elliptical cylinder, the second elliptical cylinder and the third elliptical cylinder corresponding to the first table, the second table and the third table are coaxially arranged.

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