Multi-active region semiconductor laser and its fabrication method

Abstract

This invention relates to the field of laser technology, and more particularly to a multi-active-region semiconductor laser and its fabrication method. The multi-active-region semiconductor laser includes: a stacked structure comprising, in sequence, an N-face electrode, a substrate buffer layer, a first N-type cladding, a first waveguide layer, a first P-type cladding, a tunnel junction, a second N-type cladding, a second waveguide layer, and a second P-type cladding; control channels spaced apart within the stacked structure, with the stacked structure between two adjacent control channels serving as a first central waveguide; and a confining channel located within the first central waveguide. The stacked structure on the side of the confining channel furthest from the adjacent control channel serves as a second central waveguide, the top surface of which is a current injection region, and the remaining stacked structure outside the second central waveguide is a non-injection region. This invention at least provides a multi-active-region semiconductor laser with good beam quality, minimal far-field current influence, and high brightness.

Description

Technical Field

[0001] This invention belongs to the field of laser technology, and particularly relates to a multi-active region semiconductor laser and its fabrication method. Background Technology

[0002] The brightness of a semiconductor laser is proportional to the ratio of power to beam quality. The laser power per unit solid angle reflects the brightness. In practical applications, it is often desirable for semiconductor lasers to have high output power and excellent beam quality, i.e., high brightness. However, due to the spatial structure limitations of the epitaxial structure, existing tunnel-cascaded multi-active-region semiconductor lasers, especially those with multi-layer quantum well structures, struggle to achieve good beam quality.

[0003] like Figure 1 As shown, if a second quantum well 10 is to be used, the first quantum well 11 will inevitably be etched through. Due to the etching of the first quantum well 11, the mode distribution will present as many lateral modes, and the beam quality will deteriorate rapidly. If the lateral beam quality of the first quantum well 11 is to be well controlled, the equivalent ridge width of the second quantum well 10 is often required to be large. This will cause the number of lasing modes in the second quantum well 10 to increase rapidly and the beam quality to deteriorate. If the ridge width of the top layer is small in order to achieve single mode, the small current injection window will cause the input voltage of the device to be abnormally high and the output power to decrease rapidly. Moreover, the technology is complex, the system size and cost are increased, which is not conducive to the industrial fabrication of high-power semiconductor lasers. Summary of the Invention

[0004] In view of this, the present invention aims to provide a multi-active region semiconductor laser and its fabrication method, which at least provides a multi-active region semiconductor laser with good beam quality, low influence of current in the far field, and high brightness.

[0005] To achieve the above objectives, the technical solution created by this invention is implemented as follows:

[0006] This invention provides a multi-active-region semiconductor laser, comprising: a stacked structure, the stacked structure including, in sequence, an N-type electrode, a substrate buffer layer, a first N-type cladding layer, a first waveguide layer, a first P-type cladding layer, a tunnel junction, a second N-type cladding layer, a second waveguide layer, and a second P-type cladding layer, wherein the first waveguide layer includes a first active layer, and the second waveguide layer includes a second active layer; and control channels spaced apart within the stacked structure, each control channel penetrating the second P-type cladding layer, the second waveguide layer, and the first P-type cladding layer along the thickness direction of the stacked structure. The two N-type claddings and tunnel junctions extend into the first P-type cladding. The stacked structure between two adjacent control channels serves as the first central waveguide. A confining channel is located within the first central waveguide and extends along the thickness direction of the stacked structure into the second P-type cladding. The confining channel and the adjacent control channels are arranged at intervals. The stacked structure on the side of the confining channel away from the adjacent control channel serves as the second central waveguide. The top surface of the second central waveguide is the current injection region, and the remaining stacked structure outside the second central waveguide is the non-injection region.

[0007] Furthermore, the first central waveguide has two confining channels arranged at intervals, and the second central waveguide is located between the two confining channels.

[0008] Furthermore, the first waveguide layer also includes a first N-type waveguide and a first P-type waveguide, with the first N-type waveguide located on the side of the first active layer facing the first N-type cladding and the first P-type waveguide located on the side of the first active layer facing the first P-type cladding; the second waveguide layer also includes a second N-type waveguide and a second P-type waveguide, with the second N-type waveguide located on the side of the second active layer facing the second N-type cladding and the second P-type waveguide located on the side of the second active layer facing the second P-type cladding.

[0009] Furthermore, the refractive indices of the second P-type cladding and the second N-type cladding are both less than the refractive index of the second waveguide layer; the refractive indices of the first P-type cladding and the first N-type cladding are both less than the refractive index of the first waveguide layer.

[0010] Furthermore, the multi-active semiconductor laser also includes an insulating layer and a P-side electrode. The insulating layer is located on the remaining stacked structure outside the second central waveguide, and the P-side electrode is located on the top surface of the second central waveguide. The stacked structure also includes a capping layer, which is located on the side of the second P-type cladding away from the second waveguide layer.

[0011] Furthermore, the side of the first central waveguide located on the side of the limiting channel away from the second central waveguide is a sawtooth side or a square wave side.

[0012] Furthermore, the width of the control channel can be variable or constant, or the width of the control channel can be kept constant.

[0013] Furthermore, the width of the first central waveguide can be variable or constant, while the width of the second central waveguide remains constant.

[0014] Furthermore, the edges of the first central waveguide are free curves or straight lines of arbitrary shape, and the edges of the second central waveguide are free curves or straight lines of arbitrary shape.

[0015] In another aspect, this invention provides a method for fabricating a multi-active-region semiconductor laser. The method includes: forming a stacked structure comprising, in sequence, an N-face electrode, a substrate buffer layer, a first N-type cladding layer, a first waveguide layer, a first P-type cladding layer, a tunnel junction, a second N-type cladding layer, a second waveguide layer, and a second P-type cladding layer, wherein the first waveguide layer includes a first active layer and the second waveguide layer includes a second active layer; forming spaced-apart control channels within the stacked structure, each control channel extending along the stack... The thickness direction of the stacked structure penetrates the second P-type cladding, the second waveguide layer, the second N-type cladding, and the tunnel junction, extending into the first P-type cladding. The stacked structure between two adjacent control channels serves as the first central waveguide. A confinement channel is formed within the first central waveguide, and the confinement channel extends along the thickness direction of the stacked structure into the second P-type cladding. The confinement channel and the adjacent control channel are arranged at intervals. The stacked structure on the side of the confinement channel away from the adjacent control channel serves as the second central waveguide. The top surface of the second central waveguide is the current injection region, and the remaining stacked structure outside the second central waveguide is the non-injection region.

[0016] Compared with existing technologies, the present invention achieves the following beneficial effects: The multi-active-region semiconductor laser provided by the present invention employs a modulated channel and a confined channel, which significantly improves the beam quality and brightness of the device. Specifically, the confined channel focuses on restricting the mode distribution of the fundamental mode, confining the fundamental mode within the second central waveguide, while simultaneously allowing leakage of higher-order modes. This avoids the modulated channel causing loss to the fundamental mode within the second central waveguide. By disrupting the resonance of higher-order modes, the modulated channel effectively increases the loss of higher-order modes, thereby changing the mode distribution within the device cavity and suppressing higher-order lateral modes. This further widens the loss gap between the fundamental mode and higher-order modes, effectively suppressing higher-order modes and optimizing beam quality. Furthermore, the confined channel can effectively modulate the carrier distribution in the second active layer, preventing higher-order mode lasing caused by lateral carrier accumulation, thereby improving device brightness and stabilizing the far field. Compared with traditional multi-active-region semiconductor lasers, the multi-active-region semiconductor laser provided by the present invention not only has superior beam quality and less influence from current in the far field, but also possesses higher brightness, exhibiting significant performance advantages. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A schematic diagram of a semiconductor laser with two quantum wells provided for related technologies;

[0019] Figure 2 A cross-sectional view of the multi-active region semiconductor laser described in the embodiments of the present invention;

[0020] Figure 3 A graph showing the relationship between ridge width and channel depth obtained from simulation.

[0021] Figure 4 This is a schematic diagram showing the loss characteristics under different order modes obtained from simulation.

[0022] Figure 5 This is a schematic diagram showing the loss and leakage of the fundamental mode and first-order mode of the second center waveguide under different ridge widths, calculated using the beam propagation method.

[0023] Figure 6 This is a schematic diagram showing the loss and leakage of the fundamental mode and first-order mode in the first central waveguide, calculated using the beam propagation method.

[0024] Figure 7 Simulation diagram of the mode for a multi-active region semiconductor laser without a limiting channel;

[0025] Figure 8 A mode simulation diagram of the multi-active region semiconductor laser described in the embodiments of the present invention;

[0026] Figure 9 A top view of the multi-active region semiconductor laser described in the embodiments of the present invention;

[0027] Figure 10 Another top view of the multi-active region semiconductor laser described in the embodiments of the present invention;

[0028] Figure 11 Another top view of the multi-active region semiconductor laser described in the embodiments of the present invention;

[0029] Figure 12 Another top view of the multi-active region semiconductor laser described in the embodiments of the present invention;

[0030] Figure 13 Another top view of the multi-active region semiconductor laser described in the embodiments of the present invention;

[0031] Figure 14 Another top view of the multi-active region semiconductor laser described in the embodiments of the present invention;

[0032] Figure 15 Another top view of the multi-active region semiconductor laser described in the embodiments of the present invention;

[0033] Figure 16 Another top view of the multi-active region semiconductor laser described in the embodiments of the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0036] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] refer to Figure 2 , Figures 9 to 16 This invention provides a multi-active-region semiconductor laser, comprising: a stacked structure, the stacked structure including, in sequence, an N-type electrode 116, a substrate buffer layer 101, a first N-type cladding layer 102, a first waveguide layer, a first P-type cladding layer 106, a tunnel junction 107, a second N-type cladding layer 108, a second waveguide layer, and a second P-type cladding layer 112, wherein the first waveguide layer includes a first active layer 104, and the second waveguide layer includes a second active layer 110; and control channels 201 spaced apart within the stacked structure, each control channel 201 penetrating the second P-type cladding layer 112, the second waveguide layer, and the second N-type cladding layer 108 along the thickness direction of the stacked structure. 8 and tunnel junction 107 extending into the first P-type cladding 106, the stacked structure between two adjacent control channels 201 serves as the first central waveguide 202; confining channel 203 is located within the first central waveguide 202 and extends along the thickness direction of the stacked structure into the second P-type cladding 112, the confining channel 203 is arranged at intervals with the adjacent control channels 201, the stacked structure on the side of the confining channel 203 away from the adjacent control channels 201 serves as the second central waveguide 204, the top surface of the second central waveguide 204 is the current injection region, and the remaining stacked structure outside the second central waveguide 204 is the non-injection region.

[0040] In some embodiments, the substrate buffer layer 101 is a III-V compound, such as GaAs, InP, GaSb, or GaN, and the substrate buffer layer 101 is typically N-type doped; the first active layer 104 can be a single-layer quantum well or a single-layer quantum dot, or it can be a multi-layer quantum well or a multi-layer quantum dot; the second active layer 110 can be a single-layer quantum well or a single-layer quantum dot, or it can be a multi-layer quantum well or a multi-layer quantum dot; both the first active layer 104 and the second active layer 110 are used as the gain region of the laser.

[0041] In some embodiments, the distance between the bottom of the channel 201 and the lower surface of the first P-type cladding 106 is less than the evanescent wave length of the first waveguide layer; the distance between the bottom of the channel 203 and the lower surface of the second P-type cladding 112 is limited to be less than the evanescent wave length of the second waveguide layer.

[0042] In some embodiments, the control channel 201 can be a free-curved channel with variable width.

[0043] In some embodiments, the limiting channel 203 can be a free-curved channel with a constant width.

[0044] Furthermore, the first central waveguide 202 has two spaced-apart confinement channels 203, and the second central waveguide 204 is located between the two confinement channels 203.

[0045] Furthermore, the first waveguide layer also includes a first N-type waveguide 103 and a first P-type waveguide 105. The first N-type waveguide 103 is located on the side of the first active layer 104 facing the first N-type cladding 102, and the first P-type waveguide 105 is located on the side of the first active layer 104 facing the first P-type cladding 106. The second waveguide layer also includes a second N-type waveguide 109 and a second P-type waveguide 111. The second N-type waveguide 109 is located on the side of the second active layer 110 facing the second N-type cladding 108, and the second P-type waveguide 111 is located on the side of the second active layer 110 facing the second P-type cladding 112.

[0046] Furthermore, the refractive indices of the second P-type cladding 112 and the second N-type cladding 108 are both lower than the refractive index of the second waveguide layer; the refractive indices of the first P-type cladding 106 and the first N-type cladding 102 are both lower than the refractive index of the first waveguide layer. Only in this way can a total internal reflection waveguide be formed.

[0047] Furthermore, the multi-active semiconductor laser also includes an insulating layer 114 and a P-side electrode 115. The insulating layer 114 is located on the remaining stacked structure outside the second central waveguide 204, and the P-side electrode 115 is located at least on the top surface of the second central waveguide 204. The stacked structure also includes a capping layer 113, which is located on the side of the second P-type cladding 112 away from the second waveguide layer. The capping layer 113 is a heavily doped P-type material to facilitate ohmic contact. The P-side electrode 115 and the N-side electrode 116 serve as electrodes for current injection into the laser.

[0048] Furthermore, the side of the first central waveguide 202 located on the side of the limiting channel 203 away from the second central waveguide 204 is a sawtooth side or a square wave side. The sawtooth side or square wave side, as a loss structure, increases the loss of higher-order modes in the control channel 201, and can increase the injection gain area while maintaining a certain waveguide width, which is beneficial to improving beam quality and beam brightness.

[0049] Furthermore, the width of the control channel 201 can be variable or constant, while the width of the control channel 203 is limited to remain constant.

[0050] Furthermore, the width of the first center waveguide 202 can be variable or constant, while the width of the second center waveguide 204 remains constant. In the case where the width of the first center waveguide 202 is variable, the front exit cavity surface should be the end with the larger cross-sectional area of ​​the first center waveguide 202. This helps mitigate device damage caused by catastrophic cavity surface damage.

[0051] Furthermore, the edge of the first central waveguide 202 is a free curve or a straight line of arbitrary shape, and the edge of the second central waveguide 204 is a free curve or a straight line of arbitrary shape.

[0052] The following provides a detailed explanation of the setting principles of the confinement channel 203 and the modulation channel 201 in the multi-active region semiconductor laser provided by the present invention. For any waveguide in the device, the number of mode distributions n satisfies the following relationship:

[0053] ;

[0054] Where w is the ridge width, n R With n T These are the effective refractive indices at the ridge and the etched trench, respectively. In common weak refractive index guiding devices, the difference between the two is typically 10. -4 ~10 -2 After substituting the numerical values, it can be found that when the ridge width is tens of micrometers, the device only supports a few lateral modes. However, when the active region is etched through, the effective refractive index at the channel becomes 1. This causes the number of modes supported by the device to increase sharply when the ridge width is tens of micrometers, reaching tens or even a dozen modes. This will greatly reduce the beam quality of the device, making it difficult to improve brightness. This invention, by controlling the combination of channel 201 and confinement channel 203, significantly reduces the loss of the fundamental mode. Since higher-order modes are not affected by confinement channel 203, after leaking to the outside of confinement channel 203, controlling channel 201 will generate high losses for higher-order modes, thereby achieving the fundamental mode output of the first active layer 104, ultimately achieving the goal of improving output brightness.

[0055] Figure 3 To simulate the relationship between ridge width and etching channels for different patterns, Figure 3 In the diagram, TE00 represents the fundamental mode, TE01 represents the first-order mode, TE02 represents the second-order mode, TE03 represents the third-order mode, and TE04 represents the fourth-order mode. It can be seen that for narrower ridge widths, it is easy to achieve single-mode or few-mode output by etching a channel of a certain depth. However, for wider ridge widths, it is difficult to achieve single-mode or few-mode output by adjusting the channel etching depth. Specifically, the modes near the first active layer 104 correspond to the dashed line portion, limiting this group of modes to require adjusting the ridge width by creating a deeper channel. The modes near the second active layer 110 correspond to the solid line portion, limiting this group of modes to require adjusting the ridge width by creating a shallower channel.

[0056] Figure 4To simulate and calculate the loss changes of different lateral modes when "only the control channel 201 exists" and "the control channel 201 is combined with the restrictive channel 203", it can be seen that when "only the control channel 201 exists", the loss of the fundamental mode and each higher-order mode is very close, which can easily lead to lasing of higher-order modes. However, after combining the control channel 201 with the restrictive channel 203, the loss difference between the higher-order mode and the fundamental mode is more obvious. In this way, high loss can be achieved for higher-order modes, thereby effectively improving the beam quality of the device.

[0057] Figure 5 To simulate and calculate the mode intensities of the fundamental mode and first-order mode near the second active layer 110 at different ridge widths (width of the second center waveguide), the Beam Propagation Method (BPM) can be used. This clearly shows the loss and leakage. Figure 4 It can be seen that, under the same ridge width, higher-order modes leak more, resulting in increased loss of higher-order modes. Among higher-order modes of the same order, a wider ridge width produces more leakage.

[0058] Figure 6 To simulate and calculate the leakage of the fundamental mode and the first-order mode near the first active layer 104 using the beam propagation method, it can be seen that the higher-order modes have greater loss and significantly stronger leakage compared to the fundamental mode. This proves that the non-uniform waveguide has selectivity for modes near both the first active layer 104 and the second active layer 110.

[0059] Furthermore, simulations were performed for the case of unrestricted channels and the solution provided by this invention, with reference to... Figure 7 When there are no restrictions on the channel, Figure 7 In this context, (a) represents the fundamental mode. Figure 7 (b) in the diagram represents the first-order mode. As can be seen from the mode simulation diagram, the unrestricted channel design exhibits higher-order modes. It should be noted that... Figure 7 Only the fundamental schema and the first-order mode are given. (Reference) Figure 8 The design of the limited channel 203 in this invention only has the fundamental mode and no higher-order modes.

[0060] In some embodiments, reference Figure 13 and Figure 14 By periodically varying the width of channel 201, the wider portion of channel 201 causes additional loss to higher-order modes within the first central waveguide 202, thereby improving the beam quality of the device by increasing the lasing threshold of higher-order modes. Simultaneously, in conjunction with confinement channel 203, the fundamental mode is primarily located in the second central waveguide 204, while higher-order modes leak outside confinement channel 203. By adjusting channel 201, higher-order modes present in the first central waveguide 202 can be effectively filtered out.

[0061] In some embodiments, reference Figure 10 and Figure 11 The width of the control channel 201 located on one side of the first central waveguide changes periodically. The first central waveguide 202 has only one confinement channel 203. The wider part of the control channel 201 will cause additional loss to the higher-order modes inside the first central waveguide 202. By increasing the lasing threshold of the higher-order modes, the device beam quality can be improved. At the same time, in conjunction with the confinement channel 203, the fundamental mode mainly exists in the second central waveguide 204, while the higher-order modes will leak out of the confinement channel 203. By controlling the channel 201, the higher-order modes existing in the first central waveguide 202 can be effectively filtered.

[0062] In some embodiments, reference Figure 15 and Figure 16 The first central waveguide 202 is a tilted or curved structure, which is beneficial to use the control channel 201 to cause additional loss to the higher-order modes inside the first central waveguide 202, thereby improving the beam quality of the device by increasing the lasing threshold of the higher-order modes.

[0063] It should be noted that the present invention is illustrated using a multi-active region semiconductor laser with two stacked structures in the vertical direction as an example. The solution of the present invention is also applicable to cases where there are three or more stacked structures in the vertical direction.

[0064] In another aspect, this invention provides a method for fabricating a multi-active-region semiconductor laser. The method includes: forming a stacked structure comprising, in which N-face electrodes 116, a substrate buffer layer 101, a first N-type cladding layer 102, a first waveguide layer, a first P-type cladding layer 106, a tunnel junction 107, a second N-type cladding layer 108, a second waveguide layer, and a second P-type cladding layer 112 are stacked sequentially. The first waveguide layer includes a first active layer 104, and the second waveguide layer includes a second active layer 110. Furthermore, the invention provides a method for forming spaced-apart control channels 201 within the stacked structure, each control channel 201 extending along the thickness direction of the stacked structure. The stacked structure between two adjacent control channels 201 extends through the second P-type cladding 112, the second waveguide layer, the second N-type cladding 108, and the tunnel junction 107 into the first P-type cladding 106, serving as the first central waveguide 202. A confinement channel 203 is formed within the first central waveguide 202, and the confinement channel 203 extends along the thickness direction of the stacked structure into the second P-type cladding 112. The confinement channel 203 is spaced apart from the adjacent control channels 201. The stacked structure on the side of the confinement channel 203 away from the adjacent control channels 201 serves as the second central waveguide 204. The top surface of the second central waveguide 204 is the current injection region, and the remaining stacked structure outside the second central waveguide 204 is the non-injection region.

[0065] In some embodiments, forming a stacked structure includes: sequentially growing a buffer layer, a first N-type cladding 102, a first N-type waveguide 103, a first active layer 104, a first P-type waveguide 105, a first P-type cladding 106, a tunnel junction 107, a second N-type cladding 108, a second N-type waveguide 109, a second active layer 110, a second P-type waveguide 111, a second P-type cladding 112, and a capping layer 113 on a substrate using molecular beam epitaxy or metal-organic chemical vapor deposition. The substrate and the buffer layer together constitute a substrate buffer layer 101.

[0066] In some embodiments, forming a control channel 201 within a stacked structure includes: uniformly coating photoresist on a capping layer 113, and fabricating the control channel 201 on the stacked structure using ultraviolet exposure and etching techniques through an optical mask, thereby forming a first central waveguide 202 and a non-injection region located on the side of the control channel 201 away from the first central waveguide 202.

[0067] In some embodiments, forming a confinement channel 203 within the first central waveguide 202 includes: recoating photoresist, forming the confinement channel 203 within the first central waveguide 202 using ultraviolet exposure and etching techniques through an optical mask, thereby forming a second central waveguide 204.

[0068] In some embodiments, the fabrication method of the multi-active region semiconductor laser further includes growing a silicon dioxide layer as an insulating layer 114 on the capping layer 113, and etching an ohmic contact region on the top surface of the first central waveguide 202 using optical mask, ultraviolet exposure and silicon dioxide etching techniques.

[0069] In some embodiments, the fabrication method of the multi-active region semiconductor laser further includes depositing a layer of P-type ohmic contact metal, namely P-face electrode 115, using a metal growth device.

[0070] In some embodiments, the fabrication method of the multi-active region semiconductor laser further includes thinning and polishing the substrate, cleaning it after completion, and then growing an N-face electrode 116 on the polished surface of the substrate.

[0071] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0072] 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 multiple active region semiconductor laser, characterized by, Comprising: a stack structure comprising N-face electrodes, a substrate buffer layer, a first N-type cladding layer, a first waveguide layer, a first P-type cladding layer, a tunnel junction, a second N-type cladding layer, a second waveguide layer, and a second P-type cladding layer stacked in sequence, wherein the first waveguide layer comprises a first active layer, and the second waveguide layer comprises a second active layer; regulation channels arranged at intervals in the stack structure, each regulation channel extending through the second P-type cladding layer, the second waveguide layer, the second N-type cladding layer, and the tunnel junction along the thickness direction of the stack structure and extending into the first P-type cladding layer, and the stack structure between any two adjacent regulation channels serving as a first central waveguide; a confinement channel located in the first central waveguide and extending into the second P-type cladding layer along the thickness direction of the stack structure, the confinement channel being arranged at intervals from the adjacent regulation channels, and the stack structure on the side of the confinement channel away from the adjacent regulation channels serving as a second central waveguide, the top surface of the second central waveguide being a current injection region, and the remaining stack structure outside the second central waveguide being a non-injection region.

2. The multi-active-region semiconductor laser of claim 1, wherein, The first central waveguide has two confinement channels arranged at intervals, and the second central waveguide is located between the two confinement channels.

3. The multi-active-region semiconductor laser of claim 1, wherein, The first waveguide layer further comprises a first N-type waveguide and a first P-type waveguide, the first N-type waveguide being located on the side of the first active layer facing the first N-type cladding layer, and the first P-type waveguide being located on the side of the first active layer facing the first P-type cladding layer; The second waveguide layer further comprises a second N-type waveguide and a second P-type waveguide, the second N-type waveguide being located on the side of the second active layer facing the second N-type cladding layer, and the second P-type waveguide being located on the side of the second active layer facing the second P-type cladding layer.

4. The multi-active-region semiconductor laser of claim 1, wherein, The refractive index of the second P-type cladding layer and the refractive index of the second N-type cladding layer are both less than the refractive index of the second waveguide layer; and the refractive index of the first P-type cladding layer and the refractive index of the first N-type cladding layer are both less than the refractive index of the first waveguide layer.

5. The multi-active-region semiconductor laser of claim 1, wherein, The multi-active-region semiconductor laser further comprises an insulating layer located on the remaining stack structure outside the second central waveguide, and a P-face electrode located on the top surface of the second central waveguide. The stack structure further comprises a cap layer located on the side of the second P-type cladding layer away from the second waveguide layer.

6. The multi-active-region semiconductor laser of claim 1, wherein, The side surface of the first central waveguide on the side of the confinement channel away from the second central waveguide is a zigzag side surface or a square wave side surface.

7. The multi-active-region semiconductor laser of claim 1, wherein, The width of the regulation channel is variable or constant, and the width of the confinement channel is constant.

8. The multi-active-region semiconductor laser of claim 1, wherein, The width of the first central waveguide is variable or constant, and the width of the second central waveguide is constant.

9. The multi-active-region semiconductor laser of claim 1, wherein, The edge of the first central waveguide is an arbitrary-morphology free curve or a straight line, and the edge of the second central waveguide is an arbitrary-morphology free curve or a straight line.

10. A method of fabricating a multiple active region semiconductor laser, the method comprising: providing a substrate; forming a first active region on the substrate; forming a second active region on the substrate; and forming a third active region on the substrate. A method for manufacturing the multi-active-region semiconductor laser of any one of claims 1 to 9, the method comprising: A stack structure is formed, which comprises, in sequence, an N-face electrode, a substrate buffer layer, a first N-type cladding layer, a first waveguide layer, a first P-type cladding layer, a tunnel junction, a second N-type cladding layer, a second waveguide layer, and a second P-type cladding layer, wherein the first waveguide layer comprises a first active layer, and the second waveguide layer comprises a second active layer; Regulation channels are formed in the stack structure at intervals, each regulation channel extends through the second P-type cladding layer, the second waveguide layer, the second N-type cladding layer, and the tunnel junction in the thickness direction of the stack structure and extends into the first P-type cladding layer, and the stack structure between any two adjacent regulation channels serves as a first central waveguide; A confinement channel is formed in the first central waveguide and extends into the second P-type cladding layer in the thickness direction of the stack structure, the confinement channel is arranged at intervals from the adjacent regulation channels, the stack structure on the side of the confinement channel away from the adjacent regulation channels serves as a second central waveguide, the top surface of the second central waveguide is a current injection region, and the remaining stack structure outside the second central waveguide is a non-injection region.

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