A vertical cavity surface emitting laser

Abstract

This invention discloses a vertical-cavity surface-emitting laser (VCSEL). The VCSEL includes: a substrate; a first Bragg reflector located on the surface of the substrate; an active region located on the surface of the first Bragg reflector away from the substrate, the active region comprising at least two active layers and at least one tunnel junction, with a tunnel junction disposed between any two adjacent active layers; each tunnel junction comprising a P-type tunnel sublayer and an N-type tunnel sublayer, the P-type and N-type tunnel sublayers comprising the same elements but different compositions, and an energy level barrier inside the tunnel junction used to suppress electron overflow; and a second Bragg reflector located on the surface of the active region away from the first Bragg reflector. The technical solution provided by this invention improves the epitaxial growth quality of the tunnel junction while reducing the degree of quantum escape within the tunnel junction.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more particularly to a vertical cavity surface-emitting laser. Background Technology

[0002] Vertical-cavity surface-mount lasers (VCSELs) possess many inherent advantages. For example, the exit mirror surface of a Bragg reflector can be generated through metal-organic vapor phase epitaxy (MOVPE), minimizing light loss. This results in VCSELs exhibiting low loss, high beam quality, fast modulation speed, compact structure, ease of mass production, and high device reliability, leading to their widespread application in lidar, optical communication, and detectors. Among these, VCSELs using GaAs as the active layer material are widely used in the short to medium wavelength range.

[0003] However, compared to edge-emitting lasers (EELs), the output power of single-junction vertical-cavity lasers (VCSELs) remains relatively low. Therefore, multi-junction CCSELs, employing tunnel junction structures and multiple quantum wells connected in series, have emerged to enhance output power. In this case, the tunneling efficiency of the tunnel junction directly affects important performance indicators of the CCSEL, such as optical power and power conversion efficiency (PCE). Currently, there are two main tunnel junction structures: heterojunctions and homojunctions. The advantage of heterojunctions is that suitable materials can be used to reduce absorption at specific wavelengths. Furthermore, due to the different materials, a band barrier is formed within the tunnel junction, suppressing quantum escape and improving the tunneling efficiency. However, due to the different materials, during metal-organic vapor phase epitaxial growth, there is a certain probability of dislocations or shifts in the material lattice. Therefore, the epitaxial growth quality of the tunnel junction may actually affect the performance of the CCSEL. Another type is the homogeneous tunnel junction. Because it uses the same material, the lattice quality during the metal-organic vapor phase epitaxial growth stage is relatively high. However, this results in a smoother energy level profile and a sacrifice of some wavelengths of absorption, which can affect the performance of the vertical-cavity laser (VCSEL). During tunnel junction quanta, while tunneling, some quanta do not generate tunneling current but instead cross the band barrier. This escape of quantum barriers becomes more severe as the voltage applied across the device increases. This limits the tunneling efficiency of the tunnel junction, thus affecting the optical power and other performance parameters of VCSELs with multi-junction structures. Summary of the Invention

[0004] This invention provides a vertical cavity surface-emitting laser that improves the epitaxial growth quality of tunnel junctions while reducing the escape rate of quantum particles in the tunnel junctions.

[0005] According to one aspect of the present invention, a vertical-cavity surface-emitting laser is provided, comprising:

[0006] Substrate;

[0007] A first Bragg reflector is located on the surface of the substrate;

[0008] An active region is located on the surface of the first Bragg mirror away from the substrate. The active region includes at least two active layers and at least one tunnel junction. A tunnel junction is disposed between any two adjacent active layers. Each tunnel junction includes a P-type tunnel sublayer and an N-type tunnel sublayer. The P-type tunnel sublayer and the N-type tunnel sublayer contain the same elements but have different compositions. The tunnel junction includes an energy level barrier, which is used to suppress electron overflow.

[0009] A second Bragg reflector is located on the surface of the active region away from the first Bragg reflector.

[0010] Optionally, the P-type tunnel sublayer is A(x1)BC, the N-type tunnel sublayer is A(x2)BC, the values ​​of X1 and X2 are not equal, A is the first type of element included in the P-type tunnel sublayer and the N-type tunnel sublayer, B is the second type of element included in the P-type tunnel sublayer and the N-type tunnel sublayer, and C is the third type of element included in the P-type tunnel sublayer and the N-type tunnel sublayer.

[0011] Optionally, X1 is greater than X2.

[0012] Optionally, X2 is greater than 0.

[0013] Optionally, X1 is less than 1.

[0014] Optionally, X1 is less than or equal to 0.41.

[0015] Optionally, at least two active layers include a first active layer and a second active layer, and the tunnel junction is located between the first active layer and the second active layer;

[0016] The first active layer comprises a stack of a first N-type sublayer, a first active region, and a first P-type sublayer;

[0017] The second active layer comprises a stack of a second N-type sublayer, a second active region, and a second P-type sublayer;

[0018] The P-type tunnel sub-layer and the first P-type sub-layer are stacked adjacent to each other;

[0019] The N-type tunnel sub-layer and the second N-type sub-layer are arranged adjacent to each other;

[0020] The first P-type sublayer is A(x)BC, and the second N-type sublayer is A(x)BC;

[0021] The X is equal to the X1, or the X is equal to the X2.

[0022] Optionally, A includes the element Al.

[0023] Optionally, B includes the Ga element.

[0024] Optionally, C includes an As element.

[0025] The technical solution provided in this embodiment uses the same materials for both the P-type tunneling sublayer (P-TJ) and the N-type tunneling sublayer (N-TJ). By adjusting the composition ratio of the tunnel junction materials, an energy level barrier is artificially created within the originally relatively smooth tunnel junction, reducing quantum escape and thus improving the quantum tunneling efficiency of the tunnel junction. Furthermore, it avoids the dislocation growth and strain issues caused by using different materials in heterojunction tunnel junctions. Ultimately, this will further improve the performance indicators of vertical-cavity lasers using multi-junction structures.

[0026] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the energy band structure of a homogeneous tunnel junction between two active layers provided in the prior art.

[0029] Figure 2 This is a schematic diagram of the energy band structure of a heterojunction tunnel junction provided in the prior art, where a heterojunction tunnel junction is disposed between two active layers.

[0030] Figure 3 This is a schematic diagram of a vertical cavity surface-emitting laser according to an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the energy band structure of a tunnel junction disposed between two active layers according to an embodiment of the present invention.

[0032] Figure 5 This is a schematic diagram of the energy band structure of another type of active layer provided by an embodiment of the present invention, in which a tunnel junction is disposed between two active layers. Detailed Implementation

[0033] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0035] To improve the epitaxial growth quality of tunnel junctions while reducing the escape rate of quanta in the tunnel junctions, the embodiments of the present invention provide the following technical solutions:

[0036] Figure 1 This is a schematic diagram of the energy band structure of a homogeneous tunnel junction between two active layers provided in the prior art. Figure 2 This is a schematic diagram of the energy band structure of a heterojunction tunnel junction disposed between two active layers in the prior art.

[0037] See Figure 3 , Figure 3This is a schematic diagram of a vertical cavity surface-emitting laser (VCSEL) according to an embodiment of the present invention. The VCSEL includes: a substrate 1; a first Bragg reflector 2 located on the surface of the substrate 1; an active region 3 located on the surface of the first Bragg reflector 2 away from the substrate 1, the active region 3 including at least two active layers and at least one tunnel junction, with a tunnel junction disposed between any two adjacent active layers; each tunnel junction including a P-type tunnel sublayer (P-TJ) and an N-type tunnel sublayer (N-TJ), the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) including the same elements but different compositions, the tunnel junction including an energy level barrier used to suppress electron overflow; and a second Bragg reflector 4 located on the surface of the active region 3 away from the first Bragg reflector 2.

[0038] Optionally, the vertical cavity surface-emitting laser further includes a first electrode 5, a first ohmic contact layer 6, a second ohmic contact layer 7, a second electrode 8, a first oxide layer 9, and a second oxide layer 10. The first oxide layer 9, the second oxide layer 10, and the third oxide layer 11 inside the second Bragg reflector 4, after oxidation (the oxide layer has a confining effect on the light field), form the light-emitting region 12.

[0039] For example, Figure 3 The active region 3 shows three active layers and two tunnel junctions. The three active layers are active layer 30, active layer 32 and active layer 34. A tunnel junction 31 is provided between active layer 30 and active layer 32, and a tunnel junction 33 is provided between active layer 32 and active layer 34.

[0040] Figure 3 The light emission principle of the vertical cavity surface-emitting laser shown is as follows: an electrical signal is applied to the first electrode 5 and the second electrode 8, the tunnel junction 31 is connected in series with the active layer 30 and the active layer 32, the tunnel junction 33 is connected in series with the active layer 32 and the active layer 34, the film layer of the active region 3 emits light under the action of the electrical signal, and the light is reflected by the first Bragg reflector 2 and the second Bragg reflector 4 and then emitted through the light-emitting region 12.

[0041] Figure 4 This is a schematic diagram of the energy band structure of a tunnel junction disposed between two active layers according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the energy band structure of another type of active layer with a tunnel junction disposed between two active layers, as provided in an embodiment of the present invention. Figure 4 and Figure 5 As shown, Figure 4 and Figure 5 A schematic diagram of the band structure is shown, illustrating a tunnel junction positioned between any two adjacent active layers. Figure 1 This diagram illustrates the band structure of a homogeneous tunnel junction located between any two adjacent active layers. Figure 2A schematic diagram of the band structure of a heterojunction tunnel junction is shown between any two adjacent active layers.

[0042] Figure 1 , Figure 2 , Figure 4 and Figure 5 The diagram, exemplarily, illustrates the band structure of a tunnel junction 31 connected in series with active layers 30 and 32. The tunnel junction 31 includes a P-type tunneling sublayer (P-TJ) and an N-type tunneling sublayer (N-TJ). The active layers adjacent to the P-type tunneling sublayer (P-TJ) include active layer 30 and active layer 32. Active layer 30 serves as the first active layer, and active layer 32 serves as the second active layer. Active layers 30 and 32 can represent any two adjacent active layers.

[0043] At least two active layers are included, comprising a first active layer 30 and a second active layer 32. It should be noted that active layer 30 is the first active layer, and active layer 32 is the second active layer. Active layer 30 and active layer 32 can represent any two adjacent active layers. For example, in this embodiment, the first active layer is referred to as reference numeral 30, and the second active layer as reference numeral 32. The first active layer 30 includes a stack of a first N-type sublayer (N-Layer), a first active region, and a first P-type sublayer (P-Layer). The second active layer 30 includes a stack of a second N-type sublayer (N-Layer), a second active region, and a second P-type sublayer (P-Layer). The P-type tunneling sublayer (P-TJ) and the stack of the first P-type sublayer (P-Layer) of active layer 30 are arranged adjacently, and the N-type tunneling sublayer (N-TJ) and the second N-type sublayer (N-Layer) of active layer 32 are arranged adjacently.

[0044] Tunnel junctions are widely used in multi-junction vertical-cavity surface-emitting lasers (VCSELs) and multi-junction solar cell structures. Traditional heterojunction tunnel junctions are often made of highly doped and different materials. While this creates a potential barrier at the energy levels to restrict carrier escape, dislocations in the material lattice and stress can easily lead to a decrease in wafer quality, thus reducing device performance and reliability. Homojunction tunnel junctions, on the other hand, often use the same materials and composition, resulting in continuous and smoother energy levels. While carriers tunnel through, some escape against the energy level due to thermal factors, bypassing the tunnel junction. This phenomenon becomes more pronounced with increasing temperature as the voltage across the tunnel junction increases. The technical solution provided in this embodiment artificially creates an energy level barrier with similar effects to a heterojunction tunnel junction by adjusting the composition of the tunnel junction material without changing the materials, achieving an energy level structure similar to a heterojunction tunnel junction. Therefore, by adopting this tunnel junction structure, the wafer quality degradation caused by lattice dislocations can be significantly reduced, and the energy level barrier similar to that of a heterojunction tunnel junction structure can be used to effectively suppress quantum escape and improve the overall quantum tunneling efficiency of the tunnel junction.

[0045] See Figure 1 Both the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) are made of Al(x)GaAs. Tunnel junction 31 is a homojunction tunnel junction with the same elements and composition. The energy levels at the band junction of this homojunction tunnel junction are too smooth. As a voltage is applied to both ends, while quantum tunneling occurs, some charge carriers will also escape along the smooth energy levels.

[0046] See Figure 2 The P-type tunnel sublayer (P-TJ) is Al(x)GaAs, and the N-type tunnel sublayer (N-TJ) is GaAs. Tunnel junction 31 is a heterojunction tunnel junction with different elements. Because different materials are used, the wafer quality will decrease due to stress and growth dislocations.

[0047] like Figure 4 and Figure 5As shown, tunnel junction 31 includes a P-type tunnel sublayer (P-TJ) and an N-type tunnel sublayer (N-TJ). The P-type tunnel sublayer (P-TJ) is Al(x1)GaAs, and the N-type tunnel sublayer (N-TJ) is Al(x2)GaAs. In this embodiment, the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) contain the same elements, which avoids the growth dislocations and stress damage to wafer crystals caused by heterojunction tunnel junctions. Since the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) contain the same elements but have different compositions, by adjusting the composition of the tunnel junction material, a barrier of discontinuous energy levels is artificially created. Compared with homojunction tunnel junction structures, at the same voltage, tunnel junctions with energy level barriers can effectively suppress carrier escape, thereby increasing tunneling efficiency. This also avoids the wafer quality degradation caused by growth dislocations and strain due to different materials in heterojunction tunnel junctions. For example, see Figure 4 Because P-type tunnel sublayers (P-TJ) and N-type tunnel sublayers (N-TJ) contain the same elements but have different compositions, Figure 4 There is a band discontinuity between the intermediate P-type tunneling sublayer (P-TJ) and the N-type tunneling sublayer (N-TJ), forming a level barrier E1. Alternatively, see... Figure 5 Because P-type tunnel sublayers (P-TJ) and N-type tunnel sublayers (N-TJ) contain the same elements but have different compositions, Figure 5 The band structure between the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) is discontinuous and forms a level barrier E2.

[0048] The technical solution provided in this embodiment uses the same materials for both the P-type tunneling sublayer (P-TJ) and the N-type tunneling sublayer (N-TJ). By adjusting the composition ratio of the tunnel junction materials, an energy level barrier is artificially created within the originally relatively smooth tunnel junction, reducing quantum escape and thus improving the quantum tunneling efficiency of the tunnel junction. Furthermore, it avoids the dislocation growth and strain issues caused by using different materials in heterojunction tunnel junctions. Ultimately, this will further improve the performance indicators of vertical-cavity lasers using multi-junction structures.

[0049] Optionally, based on the above technical solution, the P-type tunnel sublayer is A(x1)BC, the N-type tunnel sublayer is A(x2)BC, the values ​​of X1 and X2 are not equal, A is the first element included in the P-type tunnel sublayer and the N-type tunnel sublayer, B is the second element included in the P-type tunnel sublayer and the N-type tunnel sublayer, and C is the third element included in the P-type tunnel sublayer and the N-type tunnel sublayer.

[0050] Specifically, the P-type tunnel sublayer is A(x1)BC, and the N-type tunnel sublayer is A(x2)BC. The values ​​of X1 and X2 are not equal, so that the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) contain the same elements, which can avoid the growth dislocations and stress damage to wafer crystallization caused by the tunnel junction of the heterojunction structure. Since the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) contain the same elements but have different compositions (the values ​​of X1 and X2 are not equal), compared with the P-type tunnel sublayer (P-TJ) and N-type tunnel sublayer (N-TJ) in the homojunction structure tunnel junction, the technical solution provided in this embodiment uses the same materials on the basis of the heterojunction structure tunnel junction, only adjusting the composition of element A (Al). Therefore, it minimizes the risk of growth dislocations and strain-induced wafer quality degradation. By employing different Al (aluminum) compositions, energy level barriers are artificially created. This effectively suppresses escaping carriers when the same voltage is applied across the VCSEL, thereby improving the tunneling efficiency of the tunnel junction. It should be noted that in this embodiment of the invention, A includes Al, B includes Ga, and C includes As.

[0051] Optionally, based on the above technical solution, X1 is greater than X2.

[0052] Specifically, the P-type tunnel sublayer is A(x1)BC, and the N-type tunnel sublayer is A(x2)BC, where X1 is greater than X2. This ensures that the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) contain the same elements, avoiding the growth dislocations and stress damage to wafer crystals caused by tunnel junctions in heterojunction structures. Since the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) contain the same elements but have different compositions (X1 is greater than X2), compared to the P-type tunnel sublayer (P-TJ) and N-type tunnel sublayer (N-TJ) in homojunction structures, the technical solution provided in this embodiment includes an energy level barrier. This energy level barrier is similar to the barrier in a heterojunction structure, thereby limiting the escape of charge carriers.

[0053] Optionally, based on the above technical solution, X2 is greater than 0.

[0054] Specifically, both the P-type tunnel sublayer and the N-type tunnel sublayer include element A, making the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) contain the same element. This avoids growth dislocations and stress damage to wafer crystals caused by tunnel junctions in heterojunction structures. In this embodiment, element Al, which has good absorption properties, is selected as the A element to limit carrier escape.

[0055] Optionally, based on the above technical solution, X1 is less than 1, preferably less than or equal to 0.41. Specifically, X1 being less than 1, preferably less than or equal to 0.41, ensures that the P-type tunnel sublayer (P-TJ) and N-type tunnel sublayer (N-TJ) contain the same elements, thus avoiding growth dislocations and stress damage to wafer crystals caused by tunnel junctions in heterojunction structures. Maintaining different compositions within a similar composition range, the technical solution provided in this embodiment includes an energy level barrier, similar to the barrier in a heterojunction structure, thus limiting carrier escape.

[0056] Optionally, based on the above technical solution, at least two active layers include a first active layer and a second active layer, with the tunnel junction located between the first active layer and the second active layer; the first active layer includes a stack of a first N-type sublayer, a first active region, and a first P-type sublayer; the second active layer includes a stack of a second N-type sublayer, a second active region, and a second P-type sublayer; the stack of the P-type tunnel sublayer and the first P-type sublayer are arranged adjacent to each other; the N-type tunnel sublayer and the second N-type sublayer are arranged adjacent to each other; the first P-type sublayer is A(x)BC, and the second N-type sublayer is A(x)BC; X equals X1, or X equals X2.

[0057] See Figure 4 and Figure 5 Tunnel structure 31 includes a P-type tunnel sublayer (P-TJ) and an N-type tunnel sublayer (N-TJ). The active layers adjacent to the P-type tunnel sublayer (P-TJ) include active layer 30 and active layer 32. Active layer 30 serves as the first active layer 30, and active layer 32 serves as the second active layer 32. Active layers 30 and 32 can represent any two adjacent active layers.

[0058] The active layer includes a first active layer 30 and a second active layer 32. The first active layer 30 includes a stack of a first N-type sublayer, a first active region, and a first P-type sublayer. The second active layer 32 includes a stack of a second N-type sublayer, a second active region, and a second P-type sublayer. The P-type tunneling sublayer (P-TJ) and the stack of the first P-type sublayer of the active layer 30 are arranged adjacent to each other, and the N-type tunneling sublayer (N-TJ) and the second N-type sublayer of the active layer 32 are arranged adjacent to each other. The first P-type sublayer is A(x)BC, and the second N-type sublayer is A(x)BC. For example, see [link to example]. Figure 4 X equals X1. Since the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) contain the same elements but have different compositions, Figure 4 There is a band discontinuity between the intermediate P-type tunneling sublayer (P-TJ) and the N-type tunneling sublayer (N-TJ), forming a level barrier E1. Alternatively, see... Figure 5 X equals X². Since the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) contain the same elements but have different compositions, Figure 5 The band structure between the P-type tunnel sublayer (P-TJ) and the N-type tunnel sublayer (N-TJ) is discontinuous and forms a level barrier E2.

[0059] The above-described technical solution ensures that the P-type tunnel sublayer (P-TJ) and N-type tunnel sublayer (N-TJ) contain the same elements, thus avoiding the growth dislocations and stress damage to wafer crystals caused by tunnel junctions in heterojunction structures. However, the composition of element A is different. Therefore, compared to the P-type tunnel sublayer (P-TJ) and N-type tunnel sublayer (N-TJ) in homojunction structures, the technical solution provided in this embodiment includes an energy level barrier, which is similar to the barrier in a heterojunction structure, thereby limiting the escape of charge carriers.

[0060] In this embodiment, a first NDBR structure is grown on a GaAs substrate using a metal-organic vapor phase epitaxy (MOE) apparatus with Al(x)GaAs. The value of x is adjusted according to the specific vertical-cavity surface-emitting laser (VCSEL) wavelength and reflectivity. Taking an 808nm VCSEL as an example, the x value is distributed in the range of 0-1, the doping concentration is in the range of 1.0E+17-5.0E+18, and the thickness is approximately 10 micrometers. The oxide layer material on both sides of the active region 3 is Al(x)GaAs. The active region (including but not limited to the first and second active regions) in the active layer of the active region 3 adopts a classic three-layer quantum well structure. The wells / barrier layers can be made of materials such as AlGaAs, GaAsP, or AlGaAsP. A tunnel junction structure is formed between the multiple quantum wells, which is composed of Al(x)GaAs with different aluminum compositions. The portion near the P-junction is composed of highly C-doped Al(x1)GaAs, where x1 ranges from 1 to 0.5. The portion near the N-junction is composed of highly Te-doped Al(x2)GaAs, where x2 ranges from 0 to x1. The total thickness of the tunnel junction is in the range of 20-40 nm. A second Bragg reflector (PDBR) structure is grown on top of the active region 3, using Al(x)GaAs, where x is approximately in the range of 0-1. The doping concentration is distributed in the range of 1.0E+17-5.0E+19. Finally, a highly doped contact layer with a thickness of approximately 20 nm is grown using GaAs. After growth, the designated locations are oxidized to form an oxide layer for current confinement (i.e., the oxidation of the first oxide layer 9, the second oxide layer 10, and the third oxide layer 11 inside the second Bragg reflector 4 (the oxidation of the oxide layer has a confinement effect on the light field) forms the light-emitting region 12. Metal electrodes were deposited on both sides of the vertical cavity surface-emitting laser, quenched, cut, and tested.

[0061] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0062] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A vertical-cavity surface-emitting laser, characterized in that, include: Substrate; A first Bragg reflector is located on the surface of the substrate; An active region is located on the surface of the first Bragg mirror away from the substrate. The active region includes at least two active layers and at least one tunnel junction. A tunnel junction is disposed between any two adjacent active layers. Each tunnel junction includes a P-type tunnel sublayer and an N-type tunnel sublayer. The P-type tunnel sublayer and the N-type tunnel sublayer contain the same elements but have different compositions. The tunnel junction includes an energy level barrier, which is used to suppress electron overflow. A second Bragg reflector is located on the surface of the active region away from the first Bragg reflector; The P-type tunnel sublayer is A. x1 BC, the N-type tunnel sublayer is A x2 BC, the values ​​of X1 and X2 are not equal, A is the first element included in the P-type tunnel sublayer and the N-type tunnel sublayer, B is the second element included in the P-type tunnel sublayer and the N-type tunnel sublayer, and C is the third element included in the P-type tunnel sublayer and the N-type tunnel sublayer; X1 is greater than X2; X2 is greater than 0; X1 is less than 1; The tunnel junction comprises at least two active layers, including a first active layer and a second active layer, and is located between the first active layer and the second active layer. The first active layer comprises a stack of a first N-type sublayer, a first active region, and a first P-type sublayer; The second active layer comprises a stack of a second N-type sublayer, a second active region, and a second P-type sublayer; The P-type tunnel sub-layer and the first P-type sub-layer are stacked adjacent to each other; The N-type tunnel sub-layer and the second N-type sub-layer are arranged adjacent to each other; The first P-type sublayer is A x BC, the second N-type sublayer is A x BC; The X is equal to the X1, or the X is equal to the X2.

2. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, X1 is less than or equal to 0.

41.

3. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The A includes the element Al.

4. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The B element includes Ga.

5. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The C includes the As element.

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