Quantum well laser epitaxial structure and quantum well laser

Abstract

The invention provides a quantum well laser epitaxial structure and a quantum well laser. The epitaxial structure comprises a substrate, a buffer layer, a lower cladding, a lower waveguide layer, a quantum well active region, an upper waveguide layer, an upper cladding and a contact layer which are stacked in sequence, wherein the lower cladding is used for limiting laser leakage in a first direction, and the upper cladding is used for limiting laser leakage in a second direction; the band gap width of the lower waveguide layer is between the lower cladding and the quantum well active region, the band gap width of the lower waveguide layer is greater than the band gap width of the quantum well active region, and the refractive index of the lower waveguide layer is greater than the refractive index of the lower cladding; the quantum well active region comprises one or more quantum well layers and chirp barriers, the quantum well layers and the chirp barriers are arranged in an overlapped mode, and the chirp barriers are used for reflecting electrons and holes so as to limit the electrons and the holes to compositely emit light in the quantum well layers. According to the epitaxial structure disclosed by the invention, the interaction of electron holes is enhanced, the optical gain can be improved, the threshold current of the device is reduced, and the characteristic temperature is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of semiconductor lasers, and in particular to a quantum well laser epitaxial structure and a quantum well laser. Background Art

[0002] The mid-infrared spectral region has abundant gas characteristic absorption peaks, so lasers working in this band have great application value in gas detection, industrial processing, and scientific research. At the same time, as an important atmospheric transparent window, this type of device also has great application value in infrared countermeasures and wireless communication.

[0003] Antimonide quantum well lasers have significant advantages in the 2-4 micron operating band because of their band gaps that match the mid-infrared band and rich band structure designs. However, studies have shown that the device performance of antimonide quantum well lasers will drop significantly when the operating wavelength exceeds 2.5 microns. This significant deterioration in device performance comes from insufficient quantum well band-step confinement. Therefore, improving the quantum well's ability to confine carriers, especially holes, is an important issue in improving the operating performance of antimonide lasers at long wavelengths.

[0004] The traditional solution to improve the quantum well carrier confinement effect is to introduce a five-element alloy barrier, AlGaInAsSb. Although the five-element alloy barrier can improve the hole confinement ability to a certain extent, it will also weaken the electron confinement ability. In addition, the growth window of the five-element alloy is very narrow, and the growth is difficult. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the existing technical problems, the present disclosure provides a quantum well laser epitaxial structure and a quantum well laser, which are used to at least partially solve the above technical problems.

[0007] (II) Technical solution

[0008] The present disclosure provides a quantum well laser epitaxial structure, comprising: a substrate, a buffer layer, a lower cladding layer, a lower waveguide layer, a quantum well active region, an upper waveguide layer, an upper cladding layer and a contact layer stacked in sequence; wherein the lower cladding layer is used to limit the leakage of laser light in a first direction, and the upper cladding layer is used to limit the leakage of laser light in a second direction; the band gap width of the lower waveguide layer is between the lower cladding layer and the quantum well active region, the band gap width of the lower waveguide layer is greater than the band gap width of the quantum well active region, and the refractive index of the lower waveguide layer is greater than the refractive index of the lower cladding; the band gap width of the upper waveguide layer is between the upper cladding layer and the quantum well active region, the band gap width of the upper waveguide layer is greater than the band gap width of the quantum well active region, and the refractive index of the upper waveguide layer is greater than the refractive index of the upper cladding; and the quantum well active region comprises one or more quantum well layers and chirped potential barriers that are overlapped with each other, and the chirped potential barriers are used to reflect electrons and holes in the quantum well layer to limit the electrons and holes from recombining and emitting light in the quantum well layer.

[0009] Optionally, the chirped barrier comprises: a short-period superlattice and a thin-layer material; wherein the number of periods of the short-period superlattice is 3 to 5, and the thickness of the thin-layer material is 5 to 20 nm.

[0010] Optionally, the short-period superlattice comprises: an indium arsenide layer, an aluminum antimony layer and a gallium antimony layer stacked on each other in any order; the thin layer body material is Al 0.25～0.5 GaAsSb.

[0011] Optionally, the thickness and composition of the quantum well layer are determined according to the operating wavelength of the quantum well laser; wherein the composition of the quantum well layer is In 0.45-0.5 GaAs 0.18-0.2 Sb; and the thickness of the quantum well layer is 8 to 13 nm.

[0012] Optionally, the aluminum antimony layer is in contact with the quantum well layer.

[0013] Optionally, the lower cladding layer and the upper cladding layer are AlGaAsSb bulk materials with a high aluminum component, wherein the aluminum component is greater than or equal to 0.5.

[0014] Optionally, the lower waveguide layer and the upper waveguide layer are AlGaAsSb with a low aluminum content, wherein the aluminum content is less than or equal to 0.3.

[0015] Optionally, the substrate is lattice matched with at least one of the materials of the buffer layer, the lower cladding layer, the lower waveguide layer, the quantum well active region, the upper waveguide layer, the upper cladding layer, and the contact layer; wherein the material of the substrate is gallium antimony.

[0016] Optionally, the substrate, the buffer layer, and the lower cladding layer are N-type doped with gallium telluride; the upper cladding layer is P-type doped with beryllium; and the contact layer is a P-type beryllium-doped gallium antimony layer.

[0017] On the other hand, the present disclosure provides a quantum well laser, comprising: a quantum well laser epitaxial structure of any embodiment of the present disclosure and a plurality of electrodes; wherein one of the plurality of electrodes is in contact with a contact layer, and another of the plurality of electrodes is in contact with a substrate; and the operating wavelength of the quantum well laser is 2.6 μm to 2.9 μm.

[0018] (III) Beneficial effects

[0019] Compared with the prior art, the quantum well laser epitaxial structure and quantum well laser provided by the present disclosure have at least the following beneficial effects:

[0020] (1) The quantum well laser epitaxial structure disclosed in the present invention has a high reflective effect on electrons and holes by setting a chirped barrier next to the quantum well layer of the active region of multiple periodic quantum wells. The electrons and holes can be confined in the quantum well layer, thereby enhancing the interaction between electrons and holes, thereby improving the optical gain, reducing the device threshold current, and increasing the characteristic temperature.

[0021] (2) In the quantum well laser epitaxial structure disclosed in the present invention, the chirped barrier is composed of a short-period superlattice and a thin layer of bulk material, which does not change the electron energy level and hole energy level in the quantum well layer, that is, it does not affect the emission wavelength of the quantum well layer.

[0022] (3) The quantum well laser epitaxial structure disclosed in the present invention specifically adopts an aluminum antimony layer connected with a quantum well layer, which further improves the confinement effect on electrons and holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0024] Figure 1A A schematic diagram showing a layer structure of a quantum well laser epitaxial structure according to an embodiment of the present disclosure; Figure 1B The layer structure diagram of the quantum well active region according to the embodiment of the present disclosure is schematically shown; Figure 1C Schematically shows a layer structure diagram of a chirped barrier according to an embodiment of the present disclosure;

[0025] Figure 2 A diagram schematically shows a comparison between a quantum well active region energy band simulation diagram based on a chirped barrier structure according to an embodiment of the present disclosure and a conventional quantum well active region energy band simulation diagram;

[0026] Figure 3 A schematic diagram showing a comparison of electron and hole reflection energy spectra based on a chirped barrier structure according to an embodiment of the present disclosure and a traditional quantum well active region;

[0027] Figure 4The growth flow chart of the quantum well laser epitaxial structure according to the embodiment of the present disclosure is schematically shown.

[0028] [Description of Reference Numerals]

[0029] 1-substrate; 2-buffer layer; 3-lower cladding layer; 4-lower waveguide layer; 5-quantum well active region; 51-quantum well layer; 52-chirped barrier; 521-short period superlattice; 522-thin layer body material; 6-upper waveguide layer; 7-upper cladding layer; 8-contact layer. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0031] It should be noted that in the drawings or descriptions, similar or identical parts use the same figure numbers. The technical features in the various embodiments exemplified in the specification can be freely combined to form a new solution without conflict. In addition, each claim can be used as an embodiment alone or the technical features in each claim can be combined as a new embodiment. In the drawings, the shape or thickness of the embodiment can be expanded and simplified or conveniently indicated. Furthermore, the elements or implementations not shown or described in the drawings are in a form known to a person of ordinary skill in the art. In addition, although demonstrations of parameters containing specific values ​​may be provided herein, it should be understood that the parameters do not need to be exactly equal to the corresponding values, but can be approximated to the corresponding values ​​within an acceptable error tolerance or design constraint.

[0032] Unless there are technical obstacles or contradictions, the above-mentioned various embodiments of the present disclosure can be freely combined to form additional embodiments, and these additional embodiments are all within the protection scope of the present disclosure.

[0033] Although the present disclosure is described in conjunction with the accompanying drawings, the embodiments disclosed in the accompanying drawings are intended to exemplify the preferred embodiments of the present disclosure and should not be construed as limiting the present disclosure. The dimensional ratios in the accompanying drawings are merely illustrative and should not be construed as limiting the present disclosure.

[0034] Although some embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

[0035] First, the related terms of the embodiments of the present disclosure are explained as follows:

[0036] Superlattice: A multilayer film in which two different components are grown alternately in thin layers ranging from a few nanometers to tens of nanometers and maintain strict periodicity. In fact, it is a specific form of layered fine composite material.

[0037] Bulk material: refers to materials with three-dimensional spatial structure, uniform crystalline or amorphous substances.

[0038] Figure 1A The layer structure diagram of the quantum well laser epitaxial structure according to the embodiment of the present disclosure is schematically shown. Figure 1B The layer structure diagram of the quantum well active region according to an embodiment of the present disclosure is schematically shown.

[0039] According to the embodiments of the present disclosure, Figure 1A As shown, the quantum well laser epitaxial structure includes, for example: a substrate 1, a buffer layer 2, a lower cladding layer 3, a lower waveguide layer 4, a quantum well active region 5, an upper waveguide layer 6, an upper cladding layer 7 and a contact layer 8 stacked in sequence. Among them, the lower cladding layer 3 is used to limit the leakage of laser light in the first direction, and the upper cladding layer 7 is used to limit the leakage of laser light in the second direction. The band gap width of the lower waveguide layer 4 is between the lower cladding layer 3 and the quantum well active region 5, and the band gap width of the lower waveguide layer 4 is greater than the band gap width of the quantum well active region 5, and the refractive index of the lower waveguide layer 4 is greater than the refractive index of the lower cladding layer 3. The band gap width of the upper waveguide layer 6 is between the upper cladding layer 7 and the quantum well active region 5, and the band gap width of the upper waveguide layer 6 is greater than the band gap width of the quantum well active region 5, and the refractive index of the upper waveguide layer 6 is greater than the refractive index of the upper cladding layer 7. And as Figure 1B As shown, the quantum well active region 5 includes, for example, one or more quantum well layers 51 and chirped barriers 52 that are overlapped with each other. The chirped barriers 52 are used to reflect electrons and holes in the quantum well layers to limit the recombination and luminescence of electrons and holes in the quantum well layers 51 .

[0040] For example, the first direction may be a direction from the quantum well active region 5 to the substrate 1, and the second direction may be a direction from the quantum well active region 5 to the contact layer 8. The band gap widths of the materials of each layer from the quantum well active region 5 to the first direction, the second direction to the corresponding cladding layer increase in sequence, and the refractive index decreases in sequence, so that the laser generated by the quantum well active region 5 can be localized between the lower waveguide layer 4 and the upper waveguide layer 6 to avoid light leakage, thereby improving the optical gain.

[0041] For example, in order to improve the light confinement effect, the refractive index of the lower waveguide layer 4 may be set smaller than the refractive index of the quantum well active region 5 , and the refractive index of the upper waveguide layer 6 may be set smaller than the refractive index of the quantum well active region 5 .

[0042] It is understandable that the quantum well active region 5 can be a superposition of a period of quantum well layer 51 and chirped potential barrier 52, which can achieve the confinement of the composite luminescence of electrons and holes. In order to enhance the optical gain, the quantum well active region 5 can also be an alternating superposition of multiple periods of quantum well layer 51 and chirped potential barrier 52. For the convenience of preparation and taking into account the conductivity of the device, for example, 1 to 5 periods of quantum well layer 51 and chirped potential barrier 52 can be set.

[0043] Figure 1C The diagram schematically shows a layer structure of a chirped barrier according to an embodiment of the present disclosure.

[0044] According to the embodiments of the present disclosure, Figure 1C As shown, the chirp barrier 52 includes, for example, a short-period superlattice 521 and a thin layer of body material 522. The number of periods of the short-period superlattice 521 is, for example, 3 to 5, and the thickness of the thin layer of body material 522 is, for example, 5 to 20 nm (e.g., 10 nm). The short-period superlattice 521 includes, for example, an indium arsenide layer, an aluminum antimony layer, and a gallium antimony layer superimposed on each other in any order. The thin layer of body material 522 is, for example, Al 0.25～0.5 GaAsSb.

[0045] For example, the chirped barrier 52 is 3 to 5 periods of 0.6nm AlSb / 0.75nm InAs / 1.65nmGaSb and 5 to 10nm AlGaAsSb, where the Al component is 0.25 to 0.5. The stacking order of the short period superlattice 521 can be varied, such as InAs / GaSb / AlSb, or GaSb / AlSb / InAs.

[0046] For example, in order to more effectively confine carriers within the well layer material, 0.6 nm AlSb may be provided in contact with the quantum well layer.

[0047] According to the embodiments of the present disclosure, the thickness and composition of the quantum well layer are determined according to the operating wavelength of the quantum well laser. 0.45-0.5 GaAs 0.18-0.2 The thickness of the Sb and quantum well layers is, for example, 8 to 13 nm.

[0048] For example, in a quantum well laser, electrons and holes combine to radiate light in a quantum well (a type of quantum well), where the energy level positions of the electrons and holes determine the wavelength of the light. By adjusting the indium component or arsenic component in InGaAsSb, or adjusting the thickness of the quantum well layer, the operating wavelength of the quantum well laser can be finely controlled.

[0049] Figure 2A comparison diagram of the energy band simulation diagram of the quantum well active region based on the chirped barrier structure according to an embodiment of the present disclosure and the energy band simulation diagram of the traditional quantum well active region is schematically shown.

[0050] According to the embodiments of the present disclosure, Figure 2 As shown, setting a chirp barrier next to the quantum well layer will not change the energy level position of electrons and holes. Therefore, while adding a quantum well layer increases the confinement of electrons and holes, it does not change the operating wavelength of the quantum well laser.

[0051] According to an embodiment of the present disclosure, the lower cladding layer and the upper cladding layer are AlGaAsSb bulk materials with high aluminum content, wherein the aluminum content is greater than or equal to 0.5. The lower waveguide layer and the upper waveguide layer are AlGaAsSb with low aluminum content, wherein the aluminum content is less than or equal to 0.3.

[0052] According to an embodiment of the present disclosure, the substrate is lattice matched with at least one of the materials of the buffer layer, the lower cladding layer, the lower waveguide layer, the quantum well active region, the upper waveguide layer, the upper cladding layer, and the contact layer. The material of the substrate is gallium antimony. The substrate, the buffer layer, and the lower cladding layer are N-type doped with gallium telluride. The upper cladding layer is P-type doped with beryllium. And the contact layer is a P-type beryllium-doped gallium antimony layer.

[0053] For example, the GaSb substrate is an N-type doped substrate with a thickness of 500μm to 600μm (such as 550μm). The GaSb buffer layer is N-type doped with a thickness of about 0.2μm. The lower cladding and upper cladding AlGaAsSb are N-type and P-type doped respectively, with an aluminum component of 0.5 to 1 and a thickness of about 2μm. The lower waveguide layer and upper waveguide layer AlGaAsSb are not doped, with an aluminum component of 0.1 to 0.3 and a thickness of about 0.3μm. The contact layer GaSb layer is P-type doped with a thickness of about 0.2μm.

[0054] For example, for quantum well lasers based on GaSb-based materials, lattice matching means that the lattice constant (0.61 nm) of the epitaxially grown material is consistent with that of the substrate GaSb material.

[0055] Figure 3 A comparison diagram of electron and hole reflection energy spectra based on a chirped barrier structure and a traditional quantum well active region according to an embodiment of the present disclosure is schematically shown.

[0056] According to the embodiments of the present disclosure, based on the transmission matrix algorithm, the carrier reflection spectrum of the chirped barrier structure and the traditional quantum well active region of the present disclosure can be calculated. Figure 3 As shown, the energy corresponding to 100% reflectivity of electrons and holes is greatly improved, indicating that the chirped barrier structure proposed in the present disclosure can significantly improve the carrier confinement effect of the quantum well.

[0057] On the other hand, the present disclosure provides a quantum well laser, for example, including: a quantum well laser epitaxial structure of any embodiment of the present disclosure and a plurality of electrodes. One of the plurality of electrodes is in contact with the contact layer, and another of the plurality of electrodes is in contact with the substrate. And the operating wavelength of the quantum well laser is, for example, 2.6 μm to 2.9 μm.

[0058] For example, a quantum well laser can adopt a ridge waveguide structure, such as a double-channel ridge waveguide structure. In the embodiment of the present disclosure, the depth of the ridge waveguide structure formed by etching can be any position below the upper surface of the upper cladding layer 7 and above the lower surface of the upper waveguide layer 6, and the width of the double-channel ridge waveguide can be a narrow strip type of 5-35μm. For a single-structure strip waveguide structure, it can also be a wide strip type of about 100-200μm. It should be clear to those skilled in the art that the specific waveguide structure in this example can be multiple. The present disclosure sets a chirped barrier next to the quantum well layer. The chirped barrier structure is a high-reflection barrier designed for the electron energy level and hole energy level of the quantum well. It has a strong limiting effect on electrons and holes and can be suitable for quantum well lasers with longer wavelengths.

[0059] Figure 4 The growth flow chart of the quantum well laser epitaxial structure according to the embodiment of the present disclosure is schematically shown.

[0060] According to the embodiments of the present disclosure, Figure 4 As shown, the growth method of the quantum well laser epitaxial structure includes, for example:

[0061] S410, substrate inspection.

[0062] For example, a 2-inch GaSb (100-face growth) N-type doped substrate was taken out, and microscope inspection showed no obvious defects. Atomic force microscope scanning showed that the surface roughness was less than 0.5nm.

[0063] S420, substrate pretreatment.

[0064] For example, the substrate that meets the requirements of the first step is placed in the sample chamber of the molecular beam epitaxy equipment, and then degassed at 190°C for 1 hour in the sample chamber and 420°C for 1 hour in the buffer chamber. Finally, it is sent to the growth chamber for growth.

[0065] S430, high temperature deoxidation of the substrate.

[0066] For example, the substrate is heated to 640-680°C in the growth chamber and maintained for 10-15 minutes to remove the oxide on the substrate surface. Generally, molecular beam epitaxy equipment is equipped with a reflection high-energy electron diffractometer to monitor the growth in situ, and the diffraction image can be observed to determine the deoxidation and growth of the substrate surface.

[0067] S440, growth of various epitaxial functional layers on the substrate.

[0068] For example, the substrate is cooled to 600-630°C (such as 610°C) to grow a 300nm GaSb buffer layer, and the doping source GaTe is turned on. The surface roughness of the obtained GaSb buffer layer is, for example, less than 0.1nm. Then, the substrate is heated to 630°C for epitaxial growth of the AlGaAsSb lower cladding layer and the lower waveguide layer. The substrate temperature is then maintained at around 500°C to sequentially perform epitaxial growth of the quantum well active region, the upper waveguide layer, the upper cladding layer and the contact layer. In order to avoid high-temperature annealing in the quantum well active region, the temperature increase growth is no longer performed after the active region is grown. The chirped barrier structure proposed in the present disclosure can not only greatly improve the confinement capability of electrons and holes, but also has a large growth window and a simple growth process.

[0069] In summary, the embodiments of the present disclosure propose a quantum well laser epitaxial structure, which has a high reflective effect on electrons and holes by setting a chirped potential barrier next to the quantum well layer of the active region of multiple periodic quantum wells, thereby confining electrons and holes in the quantum well layer, enhancing the interaction between electrons and holes, and thereby improving the optical gain, reducing the device threshold current, and increasing the characteristic temperature.

[0070] The details not included in the method embodiment section are similar to those in the device embodiment section. Please refer to the device embodiment section and will not be repeated here.

[0071] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to a specific order or hierarchy.

[0072] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only reference directions of the drawings and are not intended to limit the scope of protection of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure. In addition, the shapes, sizes, and positional relationships of the components in the drawings do not reflect the actual sizes, proportions, and actual positional relationships.

[0073] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the attached claims, the disclosure is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the attached claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the disclosure.

[0074] In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. With respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", as explained in terms of "including," used as a transitional word in the claims. Any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

[0075] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A quantum well laser epitaxial structure, characterized in that: include: A substrate, a buffer layer, a lower cladding layer, a lower waveguide layer, a quantum well active region, an upper waveguide layer, an upper cladding layer and a contact layer stacked in sequence; The lower cladding is used to limit the laser leakage in the first direction, and the upper cladding is used to limit the laser leakage in the second direction; The band gap width of the lower waveguide layer is between the lower cladding layer and the quantum well active region, and the band gap width of the lower waveguide layer is greater than the band gap width of the quantum well active region, and the refractive index of the lower waveguide layer is greater than the refractive index of the lower cladding layer; The bandgap width of the upper waveguide layer is between the upper cladding layer and the quantum well active region, and the bandgap width of the upper waveguide layer is greater than the bandgap width of the quantum well active region, and the refractive index of the upper waveguide layer is greater than the refractive index of the upper cladding layer; and The quantum well active region includes one or more quantum well layers and chirped potential barriers that are overlapped with each other. The chirped potential barriers are used to reflect electrons and holes in the quantum well layers to limit the electrons and holes from recombining and emitting light in the quantum well layers.

2. The quantum well laser epitaxial structure according to claim 1, characterized in that: The chirp barrier comprises: Short-period superlattices and thin-layer materials; The period number of the short-period superlattice is 3 to 5, and the thickness of the thin-layer material is 5 to 20 nm.

3. The quantum well laser epitaxial structure according to claim 2, characterized in that: The short-period superlattice comprises: Indium arsenide layers, aluminum antimony layers, and gallium antimony layers superimposed on each other in any order; The thin layer material is Al 0.25～0.5 GaAsSb.

4. The quantum well laser epitaxial structure according to claim 3, characterized in that: The thickness and composition of the quantum well layer are determined according to the operating wavelength of the quantum well laser; Wherein, the component of the quantum well layer is In 0.45-0.5 GaAs 0.18-0.2 Sb; and The thickness of the quantum well layer is 8-13 nm.

5. The quantum well laser epitaxial structure according to claim 4, characterized in that: The aluminum antimony layer is in contact with the quantum well layer.

6. The quantum well laser epitaxial structure according to claim 1, characterized in that: The lower cladding layer and the upper cladding layer are AlGaAsSb bulk materials with a high aluminum component, wherein the aluminum component is greater than or equal to 0.

5.

7. The quantum well laser epitaxial structure according to claim 6, characterized in that: The lower waveguide layer and the upper waveguide layer are AlGaAsSb with a low aluminum content, wherein the aluminum content is less than or equal to 0.

3.

8. The quantum well laser epitaxial structure according to claim 1, characterized in that: The substrate is lattice matched with at least one of the materials of the buffer layer, the lower cladding layer, the lower waveguide layer, the quantum well active region, the upper waveguide layer, the upper cladding layer, and the contact layer; Wherein, the material of the substrate is gallium antimony.

9. The quantum well laser epitaxial structure according to claim 8, characterized in that: The substrate, the buffer layer, and the lower cladding layer are doped with N-type gallium-telluride; The upper cladding layer is P-type doped with beryllium; and The contact layer is a P-type Be doped Gallium Antimony layer.

10. A quantum well laser, characterized in that: A quantum well laser epitaxial structure comprising any one of claims 1 to 9 and a plurality of electrodes; wherein one of the plurality of electrodes is in contact with the contact layer, and another of the plurality of electrodes is in contact with the substrate; and The working wavelength of the quantum well laser is 2.6 μm to 2.9 μm.

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