Laser diode and laser structure
By using strain-compensated indium arsenide quantum dots limited by phosphide materials and alternating active and strain-compensated layers, the reliability and wavelength limitations caused by AlGaAs materials were solved, resulting in a laser diode with longer wavelength and higher performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- II VI DELAWARE INC
- Filing Date
- 2025-07-30
- Publication Date
- 2026-06-05
Smart Images
Figure CN122159052A_ABST
Abstract
Description
Technical Field
[0001] Various aspects of this disclosure relate to laser structures, such as laser diodes. Background Technology
[0002] A conventional approach to constructing laser diodes involves embedding indium arsenide (InAs) quantum dots (QDs) within indium gallium arsenide (InGaAs) quantum wells (QWs) and confining these InAs quantum dots (QDs) using an aluminum gallium arsenide (AlGaAs)-based lattice. See, for example, “InAs / InGaAs / GaAs quantum dot lasers of 1.3 μm range with enhanced optical gain,” ARKovsh et al., Journal of Crystal Growth, Vol. 251 (2003), pp. 729–736. However, this approach introduces compressive strain between the lattice layers. Historically, this strain has been controlled to avoid strain-induced defects by limiting the number of QD layers, limiting the thickness of the strained layers, and using thicker spacer layers. However, this remedy also limits the number of InAs QD layers and the achievable laser wavelength range. Abandoning and / or limiting the use of such remedies introduces heavy strain, which typically leads to reliability issues with the resulting laser diodes.
[0003] Furthermore, using AlGaAs as the confinement material for the laser active region results in a high-Al-content confinement material to provide the high confinement required for QD lasers. However, the high Al content can cause manufacturability and reliability issues due to the strong oxidation of Al-containing materials. One approach to addressing the reliability issues associated with Al-containing materials is to use an Al-free active region, such as the quantum well laser diode described by Botez et al. in U.S. Patent No. 5,889,805, which is suitable for lasing lasers with wavelengths of approximately 800 to 870 nanometers (nm).
[0004] By comparing this method with some aspects of this disclosure as set forth with reference to the accompanying drawings in the remainder of this application, additional limitations and disadvantages of conventional and traditional methods will become apparent to those skilled in the art. Summary of the Invention
[0005] As shown and / or described in combination with at least one of these figures, and as set forth more fully in the claims, is the laser diode and the associated processes for manufacturing the laser diode. Various embodiments of the laser diode may include strain-compensated indium arsenide quantum dots confined by a phosphide material. This strain compensation allows for the stacking of multiple layers of quantum dots to provide longer laser wavelengths (e.g., 1300 nanometers (nm), 1350 nm, etc.). Furthermore, confinement via the phosphide material allows for a reduction in the amount of aluminum (Al) and the associated negative effects of aluminum oxidation.
[0006] These and other advantages, aspects and novel features of this disclosure, as well as details of the embodiments shown therein, will be more fully understood from the following description and accompanying drawings. Attached Figure Description
[0007] The various features and advantages of this disclosure can be more readily understood by referring to the following detailed description taken in conjunction with the accompanying drawings, wherein the same reference numerals denote the same structural elements.
[0008] Figure 1 Embodiments of laser diodes according to various aspects of this disclosure are described.
[0009] Figure 2 Another embodiment of a laser diode according to various aspects of this disclosure is described.
[0010] Figure 3 A graph depicts a comparison of the strain of a conventional laser diode with the strain of a laser diode that includes one or more strain compensation layers.
[0011] Figure 4 A graph comparing the aluminum content of two confining materials and their corresponding band gaps at different aluminum contents is presented. Detailed Implementation
[0012] The following discussion provides various examples of laser diodes and related processes for manufacturing them. In some embodiments, the laser diode comprises strain-compensated indium arsenide quantum dots confined by a phosphide material. These examples are non-limiting, and the scope of the appended claims should not be limited to the specific examples disclosed. In the following discussion, the terms "example" and "e.g." are non-limiting.
[0013] The accompanying drawings illustrate a general construction method. Descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring this disclosure. Furthermore, elements in the drawings are not necessarily drawn to scale. For example, the dimensions of some elements in the drawings may be enlarged relative to other elements to aid in understanding the examples discussed in this disclosure. The same reference numerals in different drawings denote the same elements.
[0014] The term "and / or" means any one or more items in a list connected by "and / or". As an example, "x and / or y" means any element in the three-element set {(x), (y), (x, y)}. In other words, "x and / or y" means "one or both of x and y". As another example, "x, y and / or z" means any element in the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, "x, y and / or z" means "one or more of x, y, and z".
[0015] The terms “comprises”, “comprising”, “includes”, and / or “including” are “open-ended” terms and specify the presence of the stated feature but do not exclude the presence or addition of one or more other features.
[0016] The terms “first,” “second,” etc., are used herein to describe various elements, and these elements should not be limited by these terms. These terms are used only to distinguish one element from another. Thus, for example, a first element discussed in this disclosure may be referred to as a second element without departing from the teachings of this disclosure.
[0017] Unless otherwise specified, the term "coupled" may be used to describe two elements that are in direct contact with each other or to describe two elements that are indirectly connected by one or more other elements. For example, if element A is coupled to element B, then element A may be in direct contact with element B or indirectly connected to element B through an intermediate element C. Similarly, the terms "above" or "on" may be used to describe two elements that are in direct contact with each other or to describe two elements that are indirectly connected by one or more other elements.
[0018] Various embodiments relate to laser structures that can be described as laser diodes. Specifically, a laser diode may include an active region defined by a waveguide or optical confinement layer. The active region may include one or more active layers and one or more strain compensation layers. Each active layer may include a quantum dot in a quantum well. The laser diode may also include a cladding layer defining the confinement layer. In various embodiments, the respective layers have substantially uniform properties and may be deposited or grown on a semiconductor substrate.
[0019] The active region and confinement layers form a laser cavity characterized by its length, width, and height. The latter is essentially the total thickness of the active region between the confinement layers. Each end of the cavity can be provided with a facet through which light is emitted from the laser diode.
[0020] Now for reference Figure 1 The figure illustrates an embodiment of a laser diode 100 according to various aspects of the present disclosure. As shown, the laser diode 100 may include an active region 110, confinement layers 120U and 120L, cladding layers 130U and 130L, a contact layer 140, a buffer layer 150, and a semiconductor bulk substrate 160.
[0021] The semiconductor bulk substrate 160 may include a gallium arsenide (GaAs) substrate. The semiconductor bulk substrate 160 may include a top surface of the bulk substrate and a bottom surface of the bulk substrate opposite to the top surface of the bulk substrate. Other layers of the laser diode 100 may be epitaxially grown, stacked, and / or otherwise formed on the top surface of the bulk substrate.
[0022] The buffer layer 150 may comprise a layer of the same semiconductor material as the bulk semiconductor substrate 160. Specifically, the buffer layer 150 may comprise a GaAs layer having a top surface and a bottom surface opposite to the top surface. The GaAs layer may be epitaxially grown, stacked, or otherwise formed on the top surface of the bulk substrate such that the bottom surface of the GaAs layer covers and contacts the top surface of the bulk substrate. Specifically, the lattice structure of the buffer layer 150 may be aligned with and continue the lattice structure of the bulk semiconductor substrate 160.
[0023] The active region 110 may be defined by an upper confinement layer 120U and a lower confinement layer 120L, which may be further defined by an upper cladding layer 130U and a lower cladding layer 130L, respectively. The active region 110 may include one or more active layers 112 and one or more strain compensation layers 114. Each active layer 112 may include layers embedded in indium gallium arsenide (InGaAs). r Ga 1-r Indium arsenide (InAs) quantum dots in a quantum well of an As alloy, where 0 ≤ r ≤ 1. One or more strain compensation layers 114 may define each active layer 112 such that the bottom surface of one strain compensation layer 114 contacts the top surface of the corresponding active layer 112, and the top surface of another strain compensation layer 114 contacts the bottom surface of the corresponding active layer 112.
[0024] Due to lattice mismatch between one or more active layers 112 and the other layers of the laser diode 100, each active layer 112 can exert compressive strain on the laser diode 100. Therefore, increasing the number of active layers 112 increases the cumulative compressive strain exerted by the active layers 112 on the laser diode 100. However, if the compressive strain is too large, the strain may affect the structural integrity of the laser diode 100 and / or reduce its reliability.
[0025] To counteract the negative impact of compressive strain on the active layer 112, the laser diode 100 includes one or more strain compensation layers 114. Specifically, the strain compensation layers 114 apply tensile strain to the laser diode 100 due to lattice structure mismatch with the other layers. In short, each active layer 112 can apply strain in a first direction, and each strain compensation layer 114 can apply strain in a second direction opposite to the first direction. Therefore, by alternating the active layer 112 and the strain compensation layer 114 in the laser diode stack, the strain provided by the strain compensation layer 114 can effectively counteract the strain applied by the active layer 112. See, for example, Figure 3 .
[0026] Therefore, the active layer 112 and strain compensation layer 114 of the active region 110 can be repeated several times (e.g., t≥1). For example, the active region 110 can be implemented using two, three, four, or other alternating active layers 112 and strain compensation layers 114 (e.g., a first active layer 112, a first strain compensation layer 114 on the first active layer 112, a second active layer 112 on the first strain compensation layer 114, a second strain compensation layer 114 on the second active layer 112, etc.). Furthermore, compared to a structure without such a strain compensation layer 114, the laser diode 100 can implement a greater number of active layers 112. A greater number of active layers 112 and therefore a thicker active region 110 can improve the performance of the resulting laser diode 100. Therefore, a laser diode 100 with a greater number of active layers 112 can produce lasing light with longer wavelengths (e.g., 1300 nm, 1350 nm, etc.) and / or better performance characteristics than conventional laser diode stacks with fewer active layers and / or thinner active regions.
[0027] In addition to the repeating strain compensation layer 114, the active region 110 may include a strain compensation base layer 114B and a strain compensation cap layer 114C. The strain compensation base layer 114B and the strain compensation cap layer 114C may each be implemented in a manner similar to the repeating strain compensation layer 114 of the active region 110, but may respectively provide a base (substrate) and a cap (cap) for the active region 110. Specifically, the strain compensation base layer 114B may include a strain compensation base layer bottom surface defining the bottom surface of the active region 110, and the strain compensation cap layer 114C may include a strain compensation cap layer top surface defining the top surface of the active region 110.
[0028] As described above, the active region 110 can be defined by confinement layers 120U and 120L. The upper confinement layer 120U and the lower confinement layer 120L each may comprise aluminum gallium indium phosphide (Al2O3)2. z Ga 1-z ) 1-w In wa (P) layer, where 0 < w < 1 and 0 ≤ z < 1. Specifically, the lower confinement layer 120L may have a lower confinement layer top surface and a lower confinement layer bottom surface opposite to the lower confinement layer top surface. The lower confinement layer 120L may be epitaxially grown, stacked, or otherwise formed on the lower cladding layer 130L, as described below, such that the lower confinement layer bottom surface covers and contacts the lower cladding layer top surface. Conversely, the upper confinement layer 120U may have an upper confinement layer top surface and an upper confinement layer bottom surface opposite to the upper confinement layer top surface. The upper confinement layer 120U may be epitaxially grown, stacked, or otherwise formed on the active region 110, such that the upper cladding layer bottom surface covers and contacts the top surface of the active region 110.
[0029] As described above, the confinement layers 120U, 120L may be defined by the cladding layers 130U, 130L. Specifically, each of the upper cladding layer 130U and the lower cladding layer 130L may include aluminum gallium indium phosphide ((Al y Ga 1-y ) 1-x In x P) layer, where 0 < x < 1 and 0 ≤ y < 1. The lower cladding layer 130L may have a lower cladding layer top surface and a lower cladding layer bottom surface opposite to the lower cladding layer top surface. The lower cladding layer 130L may be epitaxially grown, stacked, or otherwise formed on the buffer layer 150, such that the lower cladding layer bottom surface covers and contacts the buffer layer top surface. Conversely, the upper cladding layer 130U may have an upper cladding layer top surface and an upper cladding layer bottom surface opposite to the upper cladding layer top surface. The upper cladding layer 130U may be epitaxially grown, stacked, or otherwise formed on the upper confinement layer 120U, such that the upper cladding layer bottom surface covers and contacts the upper confinement layer top surface.
[0030] Using AlGaInP-based materials as the confinement layers 120U, 120L and the cladding layers 130U, 130L can reduce the amount of aluminum around the active region 110. As Figure 4 shown, AlGaInP-based materials can provide a bandgap similar to that of AlGaAs-based materials at a lower aluminum content. As described above, a high aluminum content can cause manufacturability and reliability problems due to the strong oxidation of aluminum-containing materials. By using AlGaInP-based materials instead of AlGaAs-based materials, less aluminum can be used around the active region 110 to implement the laser diode 100, thereby reducing oxidation around the active region 110 and related negative effects.
[0031] Contact layer 140 may include a gallium arsenide (GaAs) layer on the upper confinement layer 120U. Specifically, contact layer 140 may include a top surface of the contact layer and a bottom surface of the contact layer opposite to the top surface. Contact layer 140 may be epitaxially grown, stacked, or otherwise formed such that the bottom surface of the contact layer covers and contacts the top surface of the confinement layer. Contact layer 140 typically provides an electrical contact through which a drive current can drive the active region 110 to emit lasing light via the facets of the laser diode 100.
[0032] The semiconductor bulk substrate 160, buffer layer 150, lower cladding layer 130L, and lower confinement layer 120L may be n-type doped to provide n-type material below the active region 110. Conversely, the upper confinement layer 120U, upper cladding layer 130U, and upper contact layer 140 may be p-type doped to provide p-type material above the active region 110. Furthermore, the x, y, w, and z values of the confinement layers 120U and 120L and the cladding layers 130U and 130L are selected such that the cladding layers 130U and 130L have a higher band gap than the confinement layers 120U and 120L.
[0033] Now for reference Figure 2 The figure illustrates an embodiment of a laser diode 200 according to various aspects of the present disclosure. As shown, the laser diode 200 may include an active region 210, confinement layers 220U and 220L, cladding layers 230U and 230L, a contact layer 240, a buffer layer 250, and a semiconductor bulk substrate 260.
[0034] The semiconductor bulk substrate 260 may include a gallium arsenide (GaAs) substrate. The semiconductor bulk substrate 260 may include a top surface of the bulk substrate and a bottom surface of the bulk substrate opposite to the top surface of the bulk substrate. Other layers of the laser diode 200 may be epitaxially grown, stacked, and / or otherwise formed on the top surface of the bulk substrate.
[0035] The buffer layer 250 may include a layer of the same semiconductor material as the bulk semiconductor substrate 260. Specifically, the buffer layer 250 may include a GaAs layer having a top surface and a bottom surface opposite to the top surface. The GaAs layer may be epitaxially grown, stacked, or otherwise formed on the top surface of the bulk substrate such that the bottom surface of the GaAs layer covers and contacts the top surface of the bulk substrate. Specifically, the lattice structure of the buffer layer 250 may be aligned with and continue the lattice structure of the bulk semiconductor substrate 260.
[0036] The active region 210 may be defined by an upper confinement layer 220U and a lower confinement layer 220L, which may be further defined by an upper cladding layer 230U and a lower cladding layer 230L. The active region 210 may include one or more active layers 212, each defining an upper strain compensation layer 214U and a lower strain compensation layer 214L. Specifically, each active layer 212 may include a semiconductor monolayer 212M and a quantum dot layer 212D. The semiconductor monolayer 212M may include a gallium phosphide (GaP) monolayer having a top surface and a bottom surface opposite to the top surface. Furthermore, the quantum dot layer 212D may include InAs quantum dots epitaxially grown, stacked, or otherwise formed on the top surface of the semiconductor monolayer 212M.
[0037] The upper strain compensation layer 214U may be epitaxially grown, stacked, or otherwise formed over the corresponding active layer 212, such that the bottom surface of the upper strain compensation layer 214U covers and contacts the top surface of the corresponding active layer 212. However, in some embodiments, In r Ga 1-r The upper wetting layer 216U of As (where 0≤r≤1) may be epitaxially grown, stacked or otherwise formed on the top surface of the corresponding active layer 212, and the upper strain compensation layer 214U may be epitaxially grown, stacked or otherwise formed on the top surface of the upper wetting layer 216U.
[0038] The monolayer 212M can be epitaxially grown, stacked, or otherwise formed above the top surface of the lower strain compensation layer 214L, such that the bottom surface of the monolayer 212M covers and contacts the top surface of the lower strain compensation layer. However, in some embodiments, In r Ga 1-r The lower wetting layer 216L of As (where 0≤r≤1) may be epitaxially grown, stacked or otherwise formed on the top surface of the lower strain compensation layer 214L, and the monolayer 212M may be epitaxially grown, stacked or otherwise formed on the top surface of the lower wetting layer 216L.
[0039] Due to lattice mismatch between one or more active layers 212 and the other layers of the laser diode 200, each active layer 212 can exert compressive strain on the laser diode 200. Therefore, increasing the number of active layers 212 increases the cumulative compressive strain exerted by the active layers 212 on the laser diode 200. However, if the compressive strain is too large, the strain may affect the structural integrity of the laser diode 200 and / or reduce its reliability.
[0040] To counteract the negative impact of compressive strain on the active layer 212, the laser diode 200 includes strain compensation layers 214U and 214L. Specifically, the strain compensation layers 214U and 214L apply tensile strain to the laser diode 200 due to lattice structure mismatch with the other layers. In short, each active layer 212 can apply strain in a first direction, and each strain compensation layer 214U and 214L can apply strain in a second direction opposite to the first direction. Therefore, by alternating the active layer 212 and the strain compensation layers 214U and 214L in the laser diode stack, the strain provided by the strain compensation layers 214U and 214L can effectively counteract the strain applied by the active layer 212. See, for example, Figure 3 .
[0041] Therefore, the active layer 212 and strain compensation layers 214U, 214L of the active region 210 can be repeated several times (e.g., t≥1). For example, the active region 110 can be implemented using two, three, four, or other alternating active layers 212 and strain compensation layers 214U, 214L (e.g., a first lower strain compensation layer 214L, a first active layer 212 on the first lower strain compensation layer 214L, a first upper strain compensation layer 214U on the first active layer 212, a second lower strain compensation layer 214L on the first upper strain compensation layer 214U, a second active layer 212 on the second lower strain compensation layer 214L, a second upper strain compensation layer 214U on the second active layer 212, etc.). Furthermore, compared to a structure without such strain compensation layers 214U, 214L, the laser diode 200 can implement a greater number of active layers 212. A greater number of active layers 212 and therefore a thicker active region 210 can improve the performance of the resulting laser diode 200. Thus, a laser diode 200 with a greater number of active layers 212 can produce lasing light with longer wavelengths (e.g., 1300 nm, 1350 nm, etc.) and / or better performance characteristics than conventional laser diode stacks with fewer active layers and / or thinner active regions.
[0042] In addition to the repeating strain compensation layers 214U and 214L, the active region 210 may include a strain compensation base layer 214B and a strain compensation cap layer 214C. The strain compensation base layer 214B and the strain compensation cap layer 214C may each be implemented in a manner similar to the repeating strain compensation layer 214 of the active region, but may respectively provide a base (substrate) and a cover for the active region 210. Specifically, the strain compensation base layer 214B may include a strain compensation base layer bottom surface defining the bottom surface of the active region 210, and the strain compensation cap layer 214C may include a strain compensation cap layer top surface defining the top surface of the active region 210.
[0043] As described above, the active region 210 may be defined by the confinement layers 220U and 220L. The upper confinement layer 220U and the lower confinement layer 220L may each include an (Al z Ga 1-z ) 1-w In w P layer, where 0 < w < 1 and 0 ≤ z < 1. Specifically, the lower confinement layer 220L may have a lower confinement layer top surface and a lower confinement layer bottom surface opposite to the lower confinement top surface. The lower confinement layer 220L may be epitaxially grown, stacked, or otherwise formed on the lower cladding layer 230L, as described below, such that the lower confinement layer bottom surface covers and contacts the lower cladding layer top surface. Conversely, the upper confinement layer 220U may have an upper confinement layer top surface and an upper confinement layer bottom surface opposite to the upper confinement top surface. The upper confinement layer 220U may be epitaxially grown, stacked, or otherwise formed on the active region 210, such that the upper cladding layer bottom surface covers and contacts the top surface of the active region 210.
[0044] As described above, the confinement layers 220U and 220L may be defined by the cladding layers 230U and 230L. Specifically, the upper cladding layer 230U and the lower cladding layer 230L may each include an (Al y Ga 1-y ) 1-x In x P layer, where 0 < x < 1 and 0 ≤ y < 1. The lower cladding layer 230L may have a lower cladding layer top surface and a lower cladding layer bottom surface opposite to the lower cladding layer top surface. The lower cladding layer 230L may be epitaxially grown, stacked, or otherwise formed on the buffer layer 250, such that the lower cladding layer bottom surface covers and contacts the buffer layer top surface. Conversely, the upper cladding layer 230U may have an upper cladding layer top surface and an upper cladding layer bottom surface opposite to the upper cladding layer top surface. The upper cladding layer 230U may be epitaxially grown, stacked, or otherwise formed on the upper confinement layer 220U, such that the upper cladding layer bottom surface covers and contacts the upper confinement layer top surface.
[0045] Using AlGaInP-based materials as the confinement layers 220U, 220L and the cladding layers 230U, 230L can reduce the amount of aluminum around the active region 210. As Figure 4 shown, AlGaInP-based materials can provide a bandgap similar to that of AlGaAs-based materials at a lower aluminum content. As described above, a high aluminum content can cause manufacturability and reliability problems due to the strong oxidation of aluminum-containing materials. By using AlGaInP-based materials instead of AlGaAs-based materials, less aluminum can be used around the active region 210 to implement the laser diode 200, thereby reducing the oxidation around the active region 210 and related negative effects.
[0046] Contact layer 240 may include a GaAs layer on the upper confinement layer 220U. Specifically, contact layer 240 may include a top surface of the contact layer and a bottom surface of the contact layer opposite to the top surface. Contact layer 240 may be epitaxially grown, stacked, or otherwise formed such that the bottom surface of the contact layer covers and contacts the top surface of the confinement layer. Contact layer 240 typically provides an electrical contact through which a drive current can drive the active region 210 to emit lasing light via the facets of the laser diode 200.
[0047] The semiconductor bulk substrate 260, buffer layer 250, lower cladding layer 230L, and lower confinement layer 220L may be n-type doped to provide n-type material below the active region 210. Conversely, the upper confinement layer 220U, upper cladding layer 230U, and upper contact layer 240 may be p-type doped to provide p-type material above the active region 210. Furthermore, the x, y, w, and z values of the confinement layers 220U and 220L and the cladding layers 230U and 230L are selected such that the cladding layers 230U and 230L have a higher band gap than the confinement layers 220U and 220L.
[0048] This disclosure includes references to certain examples; however, it will be understood by those skilled in the art that various changes and substitutions may be made without departing from the scope of this disclosure. Furthermore, modifications may be made to the disclosed examples without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the disclosed examples, but rather to include all examples falling within the scope of the appended claims.
Claims
1. A laser diode, comprising: The active region includes one or more active layers, each applying a first strain in a first direction, and one or more strain compensation layers, each applying a second strain in a second direction, which is opposite to the first direction. The upper and lower confining layers define the top and bottom surfaces of the active region; as well as The upper cladding layer and the lower cladding layer define the top surface of the upper limiting layer and the bottom surface of the lower limiting layer.
2. The laser diode according to claim 1, wherein, Each active layer consists of quantum dots in a quantum well.
3. The laser diode according to claim 1, wherein: The first strain is compressive strain; and The second strain is tensile strain.
4. The laser diode according to claim 1, wherein, The one or more active layers and the one or more strain compensation layers are stacked on top of each other.
5. The laser diode according to claim 1, wherein: The first strain compensation layer of the one or more strain compensation layers covers and contacts the top surface of the first active layer of the one or more active layers; as well as The second strain compensation layer of the one or more strain compensation layers covers and contacts the bottom surface of the first active layer of the one or more active layers.
6. The laser diode according to claim 1, wherein: Each active layer includes In r Ga 1-r InAs quantum dots in an As quantum well, where 0 ≤ r ≤ 1; and Each strain compensation layer includes GaAs 1-s P s Layer, of which 0 <s≤1。 7. The laser diode according to claim 6, wherein: The upper confinement layer and the lower confinement layer each comprise (Al z Ga 1-z ) w In 1-w P layer, where 0 < w < 1 and 0 ≤ z < 1; and The upper cladding and the lower cladding each comprise (Al y Ga 1-y ) x In 1-x P layer, where 0 < x < 1 and 0 ≤ y < 1.
8. The laser diode according to claim 1, wherein: Each active layer includes: In r Ga 1-r The lower wetting layer of As, where 0≤r≤1; GaP layer on the lower wetting layer An InAs quantum dot layer on the GaP layer; and In r Ga 1-r The upper wetting layer of As, where 0 ≤ r ≤ 1; and Each strain compensation layer includes GaAs 1-s P s , of which 0 <s≤1。 9. The laser diode according to claim 8, wherein, The upper confinement layer and the lower confinement layer each include (Al z Ga 1-z ) w In 1-w P layer, where 0 < w < 1 and 0 ≤ z < 1.
10. The laser diode according to claim 9, wherein, The upper cladding and the lower cladding each include (Al y Ga 1-y ) x In 1-x P layer, where 0 < x < 1 and 0 ≤ y < 1.
11. The laser diode according to claim 1, comprising an n-type GaAs semiconductor bulk substrate.
12. The laser diode according to claim 1, wherein: The upper cladding layer and the upper confinement layer are p-type; and The lower cladding layer and the lower confinement layer are of type n.
13. A laser structure, comprising: Semiconductor substrate; The lower cladding layer above the semiconductor substrate; A lower limiting layer above the lower cladding layer; A first strain compensation layer above the lower cladding layer; A first active layer above the first strain compensation layer, the first active layer comprising quantum dots; A second strain compensation layer above the first active layer; An upper confinement layer above the second strain compensation layer; as well as The upper cladding layer above the upper limiting layer; Wherein, the first active layer applies compressive strain to the laser structure; and The first strain compensation layer and the second strain compensation layer each apply tensile strain to the laser structure.
14. The laser structure according to claim 13, wherein: The first active layer includes a quantum well; and The quantum dot is in the quantum well.
15. The laser structure according to claim 13, comprising: A plurality of second active layers above the second strain compensation layer, wherein each second active layer comprises a quantum dot; and A plurality of third strain compensation layers above the second strain compensation layer, wherein one or more of the plurality of third strain compensation layers separate the second active layer among the plurality of second active layers.
16. The laser structure according to claim 13, wherein: The first active layer includes In r Ga 1-r InAs quantum dots in an As quantum well, where 0 ≤ r ≤ 1; and The first strain compensation layer and the second strain compensation layer each comprise GaAs. 1-s P s Layer, of which 0 <s≤1。 17. The laser structure according to claim 16, wherein, The upper confinement layer and the lower confinement layer each comprise (Al z Ga 1-z ) w In 1-w P layer, where 0 < w < 1 and 0 ≤ z < 1.
18. The laser structure according to claim 17, wherein, The upper cladding and the lower cladding each include (Al y Ga 1-y ) x In 1-x P layer, where 0 < x < 1 and 0 ≤ y < 1.
19. The laser structure according to claim 13, wherein: The first active layer includes: In r Ga 1-r The lower wetting layer of As, where 0≤r≤1; GaP layer on the lower wetting layer An InAs quantum dot layer on the GaP layer; and In r Ga 1-r The upper wetting layer of As, where 0 ≤ r ≤ 1; and The first strain compensation layer and the second strain compensation layer each comprise GaAs. 1-s P s Layer, of which 0 <s≤1。 20. The laser structure according to claim 13, wherein, The semiconductor substrate is a GaAs substrate.