A multi-wavelength vertical-cavity surface-emitting semiconductor laser and its fabrication method

Abstract

A multi-wavelength vertical-cavity surface-emitting semiconductor laser and its fabrication method are disclosed, belonging to the field of semiconductor laser technology. This invention solves the technical problems of existing technologies, which can only output a single wavelength, leading to increased system size, cost, and power consumption. Furthermore, the design of multi-region epitaxy or multiple quantum well structures results in high process complexity and an inability to maintain stable operating temperature and reliability. By introducing a defect layer with non-uniformly distributed defects into the vertical-cavity surface-emitting semiconductor laser structure, dislocation or vacancy-rich regions are formed in local areas, generating non-uniformly distributed point defects. During the epitaxial growth of the laser material, these defects are propagated to the active region, resulting in different strains in different active region areas, and consequently, different band gaps in the active region materials. This invention enables multi-wavelength output of semiconductor lasers, significantly simplifying the epitaxial growth process.

Description

Technical Field

[0001] This invention relates to the field of semiconductor laser technology, specifically to a multi-wavelength vertical-cavity surface-emitting semiconductor laser and its fabrication method. Background Technology

[0002] A VCSEL (Vertical-Cavity Surface-Emitting Semiconductor Laser) is a surface-emitting semiconductor light source that emits a laser beam perpendicular to its top surface. Individual VCSEL devices (or "apertures") are very small, typically around 10 micrometers in diameter. VCSELs are often combined into two-dimensional arrays to collectively generate higher output power levels. A typical VCSEL consists of a multilayer structure, with the active layer sandwiched between two highly reflective mirrors. The mirrors are composed of multiple semiconductor layers, each a quarter-wavelength thick, with alternating high and low refractive indices.

[0003] Compared to edge-emitting semiconductor lasers, VCSELs have the following advantages: 1) Circular beam pattern, easy to couple with optical fibers; 2) Multiple devices can be fabricated simultaneously on the same substrate, enabling two-dimensional integration, reducing costs and improving efficiency; 3) The resonant cavity length is on the order of micrometers, close to the wavelength, with a large longitudinal mode spacing, making it easy for devices to achieve single-longitudinal-mode operation, exhibiting good dynamic single-mode performance and a large relaxation oscillation frequency; 4) No need to cleave epitaxial wafers to form the resonant cavity during fabrication, the cavity length can be precisely controlled through epitaxy, and the lasing wavelength repeatability is high. With the rapid development of VCSEL epitaxial growth technology and fabrication process technology, the performance of VCSELs has also been rapidly improved, and they are widely used in 3D sensing, optical communication, optical interconnection, optical storage, infrared illumination, biomedicine, and laser pumping.

[0004] Traditional VCSEL devices can only output a single wavelength, primarily determined by the optical thickness of the resonant cavity and the band structure of the active quantum well. However, applications such as multi-channel optical communication, multi-component gas detection, and automotive lidar require multiple wavelengths of laser light, making single-wavelength lasers insufficient. Simultaneously applying lasers of different wavelengths to a system to obtain multi-wavelength lasers increases system size, cost, and power consumption. Therefore, achieving multi-wavelength laser output within a single VCSEL device is a crucial technical challenge for VCSELs. The application of multi-wavelength lasers will improve the performance of detection systems while reducing power consumption and cost.

[0005] In the prior art, Chinese patent document CN116885561A discloses "a multi-wavelength vertical-cavity surface-emitting laser and its fabrication method". The multi-wavelength vertical-cavity surface-emitting laser includes: a substrate; an active structure formed on a first region of the substrate and a first electrode formed above the active structure; wherein the active structure includes multiple cascaded active layers, and the gain peak wavelength corresponding to the quantum well of each active layer is different from the gain peak wavelength corresponding to the quantum well of other active layers; a contact electrode formed on a second region of the substrate, and a second electrode formed on the contact electrode and electrically connected to the contact electrode; a photosensitive material layer formed on the substrate, wherein the contact electrode and the active structure are formed alternately in the photosensitive material layer, and the first electrode and the second electrode are formed on the photosensitive material layer. However, this technical solution uses multiple active layers cascaded in the direction perpendicular to the substrate to form an active structure, that is, the active layers of the laser for each wavelength are vertically stacked in the direction perpendicular to the substrate. This solution has high requirements for material growth technology and increases the complexity of device fabrication process. It is necessary to epitaxially grow the active layer for each wavelength in sequence, and each active layer is connected through a tunnel junction. The growth of the tunnel junction requires heavy doping, which further puts higher requirements on material growth technology.

[0006] In summary, existing technologies suffer from several drawbacks. They can only output a single wavelength, leading to increased system size, cost, and power consumption. Furthermore, the design of multiple active region epitaxy or multiple quantum well structures results in high complexity of material growth processes and increases the difficulty of device fabrication. Summary of the Invention

[0007] This invention solves the technical problems of existing technologies that can only output a single wavelength, which leads to increased system size, cost and power consumption, and the design of multiple active region epitaxy or multiple quantum well structures leads to high material growth process complexity and increased difficulty in device fabrication.

[0008] The present invention discloses a multi-wavelength vertical cavity surface-emitting semiconductor laser, the laser comprising, in sequence, an n-type substrate, an n-type doped lower DBR, an n-type doped current transport layer, a quantum well active region, a p-type heavily doped and n-type heavily doped tunnel junction contact layer, and an n-type doped upper DBR;

[0009] Non-uniformly distributed defects are created in the n-type doped current transport layer and conducted to the active region of the quantum well, so that the material strain in different regions of the active region of the quantum well is different.

[0010] Furthermore, in one embodiment of the present invention, the fabrication of non-uniformly distributed defects in the n-type doped current transport layer specifically involves:

[0011] The growth temperature of the n-type substrate, the n-type doped DBR, the quantum well active region, the p-type heavily doped and n-type heavily doped tunnel junction contact layer, and the n-type doped DBR is 480℃~520℃. The growth temperature of the n-type doped current transport layer is 450℃~480℃, and the V / III beam current ratio is 1~2. The n-type doped current transport layer is grown at a growth temperature of 450℃~480℃ to create non-uniformly distributed defects.

[0012] Furthermore, in one embodiment of the present invention, the distribution form of the non-uniformly distributed defects is a periodic distribution in the form of stripes or a periodic distribution in the form of an array.

[0013] Furthermore, in one embodiment of the present invention, the n-type substrate is a Te-doped n-type GaSb substrate.

[0014] Furthermore, in one embodiment of the present invention, the n-type doped DBR uses AlAsSb and GaSb, with a pair count of 22 to 24 pairs and a doping concentration of 1.3 × 10⁻⁶. 18 cm -3 The composition of AlAsSb is AlAs 0.09 Sb 0.91 The refractive index difference is 0.7.

[0015] Furthermore, in one embodiment of the present invention, the n-type doped DBR uses AlAsSb and GaSb, forming 20 to 22 pairs, with a doping concentration of 1.3 × 10⁻⁶. 18 cm -3 The composition of AlAsSb is AlAs 0.09 Sb 0.91 The refractive index difference is 0.7.

[0016] Furthermore, in one embodiment of the present invention, the active region of the quantum well is a type I quantum well structure, employing GaInAsSb and AlGaAsSb, with the well layer composition being Ga... 0.57 In 0.43 As 0.16 Sb 0.84 The well layer thickness is 6nm~10nm, and the barrier layer composition is Al. 0.35 Ga 0.65 As 0.04 Sb 0.96 The barrier layer thickness is 15nm~20nm, the V / III beam current ratio is 2~3 during quantum well active region growth, and the growth rate is 1~1.5 atomic layers per second.

[0017] Furthermore, in one embodiment of the present invention, the p-type heavily doped and n-type heavily doped tunnel junction contact layer is made of p++ GaSb and n++ InAsSb, with a doping concentration of 2×10⁻⁶.19 cm -3 ~5×10 19 cm -3 .

[0018] Furthermore, in one embodiment of the present invention, according to the above-described multi-wavelength vertical-cavity surface-emitting semiconductor laser, the fabrication of non-uniformly distributed defects in the n-type doped current transport layer specifically involves:

[0019] Ion implantation was performed on the n-type doped current transport layer at a dose of 1 × 10⁻⁶ ions. 13 ions / cm 2 ~9×10 14 ions / cm 2 When the implanted ion energy is 40 keV to 100 keV, non-uniformly distributed defects are obtained.

[0020] This embodiment describes a method for fabricating a multi-wavelength vertical-cavity surface-emitting semiconductor laser. The method, used to fabricate the aforementioned multi-wavelength vertical-cavity surface-emitting semiconductor laser, includes the following steps:

[0021] Step 1: Epitaxially grow n-type doped DBR on an n-type substrate at a growth temperature of 480℃;

[0022] Step 2: An n-type doped current transport layer is epitaxially grown on the n-type doped DBR at a growth temperature of 450℃, so that different local regions of the n-type doped current transport layer form dislocation enrichment regions or vacancy enrichment regions respectively, resulting in non-uniformly distributed defects.

[0023] Step 3: Epitaxially grow a quantum well active region on the n-type doped current transport layer at a growth temperature of 480℃. The non-uniformly distributed defects of the n-type doped current transport layer are propagated to the quantum well active region along the epitaxial direction, causing different degrees of compressive or tensile strain in the quantum well layer in different regions of the quantum well active region, resulting in different laser emission wavelengths in different regions of the quantum well active region.

[0024] Step 4: Epitaxially grow p-type heavily doped and n-type heavily doped tunnel junction contact layers on the active region of the quantum well at a growth temperature of 480℃.

[0025] Step 5: Epitaxially grow n-type doped DBR on the p-type heavily doped and n-type heavily doped tunnel junction contact layer at a growth temperature of 480℃ to complete the fabrication of the multi-wavelength vertical cavity surface-emitting semiconductor laser.

[0026] This invention solves the technical problems of existing technologies, which can only output a single wavelength, leading to increased system size, cost, and power consumption. Furthermore, the design of multiple active region epitaxy or multiple quantum well structures results in high complexity of material growth processes, increasing the difficulty of device fabrication. Specific beneficial effects include:

[0027] This invention proposes a multi-wavelength vertical-cavity surface-emitting semiconductor laser that does not require multiple active region epitaxy or multiple quantum well structures. By introducing a controllable non-uniform defect distribution in the n-type current transport layer, epitaxial growth is achieved in a single epitaxial growth process within the same epitaxial system. Due to the conduction of defects, the active region exhibits different band gaps under the same material conditions, thereby achieving multi-wavelength output. This significantly simplifies the epitaxial growth process. Furthermore, since the strain distribution in the active region is determined by the distribution of static defects, it does not rely on external mechanical adjustment or external cavity structures, and also has good operating temperature stability and reliability, reducing the difficulty of device fabrication. Attached Figure Description

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 This is a schematic diagram of the laser structure described in Embodiment 1. Detailed Implementation

[0030] Various embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. The embodiments described with reference to the drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0031] Implementation Method 1

[0032] A multi-wavelength vertical cavity surface-emitting semiconductor laser, the laser comprising, in sequence, an n-type substrate 1, an n-type doped lower DBR 2, an n-type doped current transport layer 3, a quantum well active region 4, a p-type heavily doped and n-type heavily doped tunnel junction contact layer 5, and an n-type doped upper DBR 6;

[0033] Non-uniformly distributed defects are created in the n-type doped current transport layer 3 and conducted to the active region 4 of the quantum well, so that the material strain in different regions of the active region 4 of the quantum well is different.

[0034] In existing technologies, traditional VCSEL devices can only output a single wavelength. However, in applications such as multi-channel optical communication, gas multi-component detection, and automotive lidar, multiple wavelengths of laser are required. A single wavelength laser can hardly meet the system requirements. Traditional solutions usually use multi-region epitaxy or multiple quantum well structures. However, this approach leads to high process complexity, requiring repeated epitaxy, photolithography, and implantation steps, increasing operational difficulty, and making it difficult to guarantee the stability and reliability of the operating temperature.

[0035] To address the aforementioned problems, this embodiment provides a multi-wavelength vertical-cavity surface-emitting semiconductor laser, such as... Figure 1As shown, by adding a defect layer with non-uniformly distributed defects to the structure of a vertical cavity surface-emitting semiconductor laser, the defects are conducted to the active region 4 of the quantum well during the epitaxial growth of the laser material, resulting in different strains of the active region material in different regions, which in turn causes different band gaps of the active region material in different regions, and ultimately, different laser wavelengths output by the laser in different regions.

[0036] Compared with existing technologies, by introducing a controllable non-uniform defect distribution, different distributions of the active region bandgap can be achieved in a single epitaxial growth within the same epitaxial system, thereby realizing multi-wavelength output. This greatly simplifies the epitaxial growth process and solves the technical problems of existing technologies that can only output a single wavelength, leading to increased system size, cost, and power consumption. Furthermore, the design of multiple active region epitaxy or multiple quantum well structures leads to high material growth process complexity and increases the difficulty of device fabrication. This enables the realization of a multi-wavelength vertical cavity surface-emitting semiconductor laser.

[0037] Implementation Method 2

[0038] This embodiment further defines the multi-wavelength vertical-cavity surface-emitting semiconductor laser described in Embodiment 1. Specifically, the fabrication of non-uniformly distributed defects in the n-type doped current transport layer 3 involves:

[0039] The growth temperature of the n-type substrate 1, the n-type doped DBR 2, the quantum well active region 4, the p-type heavily doped and n-type heavily doped tunnel junction contact layer 5, and the n-type doped DBR 6 is 480℃~520℃. The growth temperature of the n-type doped current transport layer 3 is 450℃~480℃, and the V / III beam current ratio is 1~2. The n-type doped current transport layer 3 is grown at a growth temperature of 450℃~480℃ to create non-uniformly distributed defects.

[0040] This embodiment increases the number of defects in the n-type doped current transport layer 3 by growing the n-type doped current transport layer 3 at a temperature lower than that of other layers in the laser structure. The presence of defects causes different degrees of strain at different positions of the active layer on the n-type doped current transport layer 3. The beneficial effect is that the band gap size of the active layer is different at different positions under the same material and composition, resulting in different laser output wavelengths.

[0041] Implementation Method 3

[0042] This embodiment further defines the multi-wavelength vertical cavity surface-emitting semiconductor laser described in Embodiment 1, wherein the non-uniformly distributed defects are distributed in a strip-shaped periodic distribution or an array-shaped periodic distribution.

[0043] Implementation Method 4

[0044] This embodiment further defines the multi-wavelength vertical cavity surface-emitting semiconductor laser described in Embodiment 1, wherein the n-type substrate 1 is a Te (tellurium) doped n-type GaSb (gallium antimonide) substrate.

[0045] Implementation Method 5

[0046] This embodiment further defines the multi-wavelength vertical-cavity surface-emitting semiconductor laser described in Embodiment 1. The n-type doped DBR 2 uses AlAsSb (aluminum antimony arsenide) and GaSb, with 22 to 24 dopant pairs, and a doping concentration of 1.3 × 10⁻⁶. 18 cm -3 The composition of AlAsSb is AlAs 0.09 Sb 0.91 The refractive index difference is 0.7.

[0047] Implementation Method Six

[0048] This embodiment further defines the multi-wavelength vertical-cavity surface-emitting semiconductor laser described in Embodiment 1. The n-type doped DBR 6 uses AlAsSb and GaSb, with 20 to 22 pairs of doped components, and a doping concentration of 1.3 × 10⁻⁶. 18 cm -3 The composition of AlAsSb is AlAs 0.09 Sb 0.91 The refractive index difference is 0.7.

[0049] Implementation Method Seven

[0050] This embodiment further defines the multi-wavelength vertical-cavity surface-emitting semiconductor laser described in Embodiment 1. The active region 4 of the quantum well is a type I quantum well structure, using GaInAsSb (gallium indium antimony arsenide) and AlGaAsSb (aluminum antimony arsenide), and the well layer composition is Ga... 0.57 In 0.43 As 0.16 Sb 0.84 The well layer thickness is 6nm~10nm, and the barrier layer composition is Al. 0.35 Ga 0.65 As 0.04 Sb 0.96 The barrier layer thickness is 15nm~20nm, the V / III beam current ratio is 2~3 during the growth of the quantum well active region 4, and the growth rate is 1~1.5 atomic layers per second.

[0051] Implementation Method Eight

[0052] This embodiment further defines the multi-wavelength vertical-cavity surface-emitting semiconductor laser described in Embodiment 1. The p-type heavily doped and n-type heavily doped tunnel junction contact layer 5 uses p++ GaSb (gallium antimonyb) 5a and n++ InAsSb (indium arsenide antimony) 5b, with a doping concentration of 2×10⁻⁶. 19 cm -3 ~5×10 19 cm -3 .

[0053] Implementation Method Nine

[0054] This embodiment further defines the multi-wavelength vertical-cavity surface-emitting semiconductor laser described in Embodiment 1. Specifically, the fabrication of non-uniformly distributed defects in the n-type doped current transport layer 3 involves:

[0055] Ion implantation was performed on the n-type doped current transport layer 3, with an implantation ion dose of 1×10⁻⁶. 13 ions / cm 2 ~9×10 14 ions / cm 2 When the implanted ion energy is 40 keV to 100 keV, non-uniformly distributed defects are obtained.

[0056] In this embodiment, the implanted ions include Si, B, Al, N, or P.

[0057] Ion implantation is a process that uses an electric field to accelerate impurity ions and precisely implant them into a semiconductor substrate to form a specific conductive region. It features high precision, low temperature, and strong controllability, and is widely used in semiconductor device manufacturing.

[0058] In this embodiment, by bombarding the n-type doped current transport layer 3 with an ion beam, non-uniformly distributed defects are generated in the n-type doped current transport layer 3. Due to the presence of defects, different positions of the active layer on the n-type doped current transport layer 3 have different degrees of strain, and finally the technical effect of multi-wavelength output of laser material is obtained.

[0059] Implementation Method Ten

[0060] This embodiment is a specific example of a multi-wavelength vertical-cavity surface-emitting semiconductor laser based on Embodiment Nine, specifically as follows:

[0061] In this embodiment, after the n-type doped current transport layer 3 is grown, the sample is placed in an ion implanter at a density of 1.5 × 10⁻⁶. 13 ions / cm 2 At a dose of 60 keV, Si ions were implanted at room temperature. The Si ion implantation caused simple point defects, resulting in non-uniformly distributed defects.

[0062] Implementation Method Eleven

[0063] This embodiment describes a method for fabricating a multi-wavelength vertical-cavity surface-emitting semiconductor laser. The method, used to fabricate any of the multi-wavelength vertical-cavity surface-emitting semiconductor lasers described in embodiments one through eight, includes the following steps:

[0064] Step 1: Epitaxially grow n-type doped DBR 2 on n-type substrate 1 at a growth temperature of 480℃;

[0065] Step 2: An n-type doped current transport layer 3 is epitaxially grown on the n-type doped DBR 2 at a growth temperature of 450℃, so that different local regions of the n-type doped current transport layer 3 form dislocation enrichment regions or vacancy enrichment regions respectively, resulting in non-uniformly distributed defects.

[0066] Step 3: Epitaxially grow a quantum well active region 4 on the n-type doped current transport layer 3 at a growth temperature of 480℃. The non-uniformly distributed defects of the n-type doped current transport layer 3 are propagated to the quantum well active region 4 along the epitaxial direction, causing different degrees of compressive or tensile strain in the quantum well layer in different regions of the quantum well active region 4, thus forming different laser emission wavelengths in different regions of the quantum well active region 4.

[0067] Step 4: Epitaxially grow p-type heavily doped and n-type heavily doped tunnel junction contact layer 5 on the active region 4 of the quantum well at a growth temperature of 480℃.

[0068] Step 5: An n-type doped DBR 6 is epitaxially grown on the p-type heavily doped and n-type heavily doped tunnel junction contact layer 5 at a growth temperature of 480℃, thus completing the fabrication of a multi-wavelength vertical-cavity surface-emitting semiconductor laser.

[0069] The specific process for fabricating materials for multi-wavelength vertical-cavity surface-emitting semiconductor lasers is as follows:

[0070] An n-type doped AlAsSb / GaSb under-phase laser beam (DBR) was epitaxially grown on an n-type GaSb substrate at a growth temperature of 480°C. An n-type GaSb-doped current transport layer was epitaxially grown on the n-type doped AlAsSb / GaSb under-phase DBR at a growth temperature of 450°C. The growth temperature of this n-type doped current transport layer is lower than that of the n-type doped AlAsSb / GaSb under-phase DBR. By introducing a low-temperature spacer layer, dislocation or vacancy-rich regions are formed in local areas, easily generating non-uniformly distributed point defects. These defects are periodically or quasi-randomly distributed in the planar direction. A GaInAsSb / AlGaAsSb I-type quantum well active region was epitaxially grown on the n-type doped GaSb current transport layer at a growth temperature of 480°C. Defects in the current transport layer propagate along the epitaxial direction to the active region, causing different degrees of compressive or tensile strain in different regions of the quantum well layer, thereby forming different laser emission wavelengths at different locations. The GaInAsSb / AlGaAsSb... Heavy doped GaSb (p++) / InAsSb (n++) tunnel junctions are epitaxially grown on the active region of a type I quantum well at a growth temperature of 480℃ for electron-hole conversion; n-type doped AlAsSb / GaSb DBRs are epitaxially grown on the contact layer of the tunnel junction at a growth temperature of 480℃ to complete the growth of laser materials.

[0071] This embodiment introduces a defect layer with non-uniformly distributed defects into the vertical cavity surface-emitting semiconductor laser structure, causing dislocation or vacancy-rich regions to form in local areas, resulting in non-uniformly distributed point defects. During the epitaxial growth of the laser material, these defects are propagated to the active region, leading to different strains in the active region material in different areas, and consequently, different band gaps in the active region material in different areas. This solves the technical problems of existing technologies that can only output a single wavelength, resulting in increased system size, cost, and power consumption, and that designs with multiple active region epitaxy or multiple quantum well structures lead to high material growth process complexity and increased difficulty in device fabrication.

[0072] Implementation Method Twelve

[0073] This embodiment is based on any of the multi-wavelength vertical-cavity surface-emitting semiconductor lasers described in Embodiments 1 to 8, and the fabrication method of the multi-wavelength vertical-cavity surface-emitting semiconductor laser described in Embodiment 11. Three specific embodiments are proposed, with the fabrication of 2.3μm antimonide vertical-cavity surface-emitting semiconductor laser material as an example for further detailed description.

[0074] Example 1

[0075] Step 1: After degassing the Te-doped n-GaSb substrate at 150°C, the oxide layer on the substrate surface is removed at 555°C under antimony beam protection. The surface reconstruction transition is monitored using RHEED (reflection high-energy electron diffractometer) to ensure that the surface is flat and free of residual oxygen.

[0076] Step 2: Set the growth temperature to 480℃ and grow 24 pairs of AlAs on a Te-doped n-GaSb substrate. 0.09 Sb 0.91 A GaSb 1 / 4 wavelength DBR (distributed Bragg reflector) layer with Te as the doping source and a doping concentration of 1.3 × 10⁻⁶. 18 cm -3 AlAs 0.09 Sb 0.91 The GaSb substrate has a lattice match with the GaSb substrate, a refractive index difference of approximately 0.7, and a reflectivity >99%.

[0077] Step 3: Set the growth temperature to 450℃ and epitaxially grow an n-type GaSb current transport layer. During the epitaxial growth process, control the substrate temperature gradient to ±10℃. Under the lower growth temperature condition, make the spatial distribution of the defect density at the growth interface point, thereby forming a non-uniformly distributed stress partition on the surface of the epitaxial layer.

[0078] Step 4: Increase the growth temperature to 480℃ for epitaxial growth of Ga. 0.57 In 0.43 As 0.16 Sb 0.84 / Al 0.35 Ga 0.65 As 0.04 Sb 0.96 The type I quantum well active region has a well layer thickness of 8 nm, a barrier layer thickness of 20 nm, a V / III beam current ratio of 2, and a growth rate of 1 mL / s. Due to the strain conduction induced by defects in the underlying current transport layer, the quantum well active region generates different degrees of strain at different locations, with a bandgap difference of about 20~40 meV, thus forming different emission wavelength regions.

[0079] Step 5: Set the growth temperature to 480℃ and epitaxially grow a Be-doped GaSb (p++) / Te-doped InAsSb (n++) tunnel junction with a doping concentration of 2×10⁻⁶. 19 cm -3 ;

[0080] Step 6: Set the growth temperature to 480℃ and grow 20 pairs of AlAs on the tunnel junction. 0.09 Sb 0.91 / GaSb 1 / 4 wavelength DBR layer, doped with Te source, doping concentration of 1.3×10 18 cm -3 AlAs 0.09 Sb 0.91 The GaSb lattice is matched with the GaSb substrate, the refractive index difference is about 0.7, and the reflectivity is >99%.

[0081] Example 2

[0082] The defect region of the n-type GaSb current transport layer is set into a strip shape, and the defect density of the two groups of regions is 2×10⁻⁶. 8 cm -2 With 5×10 7 cm -2 This enables two bandgap variations in the active region of the quantum well, thus realizing a dual-wavelength vertical cavity surface-emitting laser. The other parts of Example 2 are the same as those of Example 1.

[0083] Example 3

[0084] The defect region of the n-type GaSb current transport layer is periodically implanted with ions through a photolithographic mask to achieve an array-shaped defect distribution, thereby realizing the change of the bandgap of the active region of the quantum well into an array distribution, and thus realizing an array-shaped multi-wavelength vertical cavity surface-emitting laser. The other parts of Example 3 are the same as those of Example 1.

[0085] The foregoing has provided a detailed description of a multi-wavelength vertical-cavity surface-emitting semiconductor laser and its fabrication method. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A multi-wavelength vertical cavity surface emitting semiconductor laser, the laser comprising an n-type substrate (1), an n-type doped lower DBR (2), an n-type doped current transport layer (3), a quantum well active region (4), a p-type heavily doped and n-type heavily doped tunnel junction contact layer (5) and an n-type doped upper DBR (6) arranged in sequence, characterized in that: non-uniform defects are manufactured in the n-type doped current transport layer (3), the non-uniform defects are conducted to the quantum well active region (4), and the material in different regions of the quantum well active region (4) is made to have different material strains; the non-uniform defects make different local regions of the n-type doped current transport layer form dislocation-rich regions or vacancy-rich regions respectively. The non-uniform defects are manufactured in the n-type doped current transport layer (3), specifically as follows: the growth temperature of the n-type substrate (1), the n-type doped lower DBR (2), the quantum well active region (4), the p-type heavily doped and n-type heavily doped tunnel junction contact layer (5) and the n-type doped upper DBR (6) is 480℃-520℃, the growth temperature of the n-type doped current transport layer (3) is 450℃-480℃, and the V / III beam ratio is 1-2; the non-uniform defects are manufactured in the n-type doped current transport layer (3) at the growth temperature of 450℃-480℃. The distribution form of the non-uniform defects is a strip form periodic distribution or an array form periodic distribution.

2. The multi-wavelength vertical cavity surface emitting semiconductor laser according to claim 1, wherein The n-type substrate (1) is a Te-doped n-type GaSb substrate. The non-uniform defects are manufactured in the n-type doped current transport layer (3), specifically as follows:

3. The multi-wavelength vertical cavity surface emitting semiconductor laser according to claim 1, wherein, The method comprises the following steps:

4. The multi-wavelength vertical cavity surface emitting semiconductor laser according to claim 1, wherein Step 1: epitaxially growing the n-type doped lower DBR (2) on the n-type substrate (1) at a growth temperature of 480℃; 5. The multi-wavelength vertical cavity surface emitting semiconductor laser according to claim 1, wherein The n-type doped lower DBR (2) adopts AlAsSb and GaSb, the pair number of the composition is 22 pairs to 24 pairs, and the doping concentration is 1.3×10 18 cm -3 -3. The composition of AlAsSb is AlAs 0.09 Sb 0.91 , and the refractive index difference is 0.

7.

6. The multi-wavelength vertical cavity surface emitting semiconductor laser according to claim 1, wherein The n-type doped upper DBR (6) adopts AlAsSb and GaSb, the pair number of the composition is 20 pairs to 22 pairs, and the doping concentration is 1.3×10 18 cm -3 -3. The composition of AlAsSb is AlAs 0.09 Sb 0.91 , and the refractive index difference is 0.

7.

7. The multi-wavelength vertical cavity surface emitting semiconductor laser according to claim 1, wherein The quantum well active region (4) is I type quantum well structure, adopts GaInAsSb and AlGaAsSb, the well layer component is Ga 0.57 In 0.43 As 0.16 Sb 0.84 , the well layer thickness is 6nm~10nm, the barrier layer component is Al 0.35 Ga 0.65 As 0.04 Sb 0.96 , the barrier layer thickness is 15nm~20nm, the V / III beam flow ratio is 2~3 when the quantum well active region (4) grows, and the growth rate is 1~1.5 atomic layers per second.

8. The multi-wavelength vertical cavity surface emitting semiconductor laser according to claim 1, wherein, The p-type heavily doped and n-type heavily doped tunnel junction contact layer (5) adopts p++ GaSb (5a) and n++ InAsSb (5b), and the doping concentration is 2x10 19 cm -3 ~5x10 19 cm -3 .

9. The multi-wavelength vertical cavity surface emitting semiconductor laser according to claim 1, wherein, Step 2: epitaxially growing the n-type doped current transport layer (3) on the n-type doped lower DBR (2) at a growth temperature of 450℃, so that different local regions of the n-type doped current transport layer (3) form dislocation-rich regions or vacancy-rich regions respectively, and non-uniform defects are obtained; The n-type doped current transport layer (3) is ion implanted, the ion dose is 1×10 13 ions / cm 2 ~9×10 14 ions / cm 2 , and the ion energy is 40 keV~100 keV, so that the non-uniform distribution defects are obtained.

10. A method for fabricating a multi-wavelength vertical cavity surface emitting semiconductor laser, the method being used for fabricating the multi-wavelength vertical cavity surface emitting semiconductor laser according to any one of claims 1 to 8, characterized in that, Step 3: epitaxially growing the quantum well active region (4) on the n-type doped current transport layer (3) at a growth temperature of 480℃, the non-uniform defects of the n-type doped current transport layer (3) are transferred to the quantum well active region (4) along the epitaxial direction, the quantum well layers in different regions of the quantum well active region (4) are subjected to different degrees of compressive strain or tensile strain, and different laser emission wavelengths are formed in different regions of the quantum well active region (4) ; Step 4: epitaxially growing the p-type heavily doped and n-type heavily doped tunnel junction contact layer (5) on the quantum well active region (4) at a growth temperature of 480℃; Step 5: epitaxially growing the n-type doped upper DBR (6) on the p-type heavily doped and n-type heavily doped tunnel junction contact layer (5) at a growth temperature of 480℃, and the preparation of the multi-wavelength vertical cavity surface emitting semiconductor laser is completed. ​ ​ ​

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