Semiconductor laser and current control method thereof

Abstract

The application relates to the technical field of semiconductors, and discloses a semiconductor laser and a current control method thereof, which comprise an epitaxial structure and a packaging carrier; the epitaxial structure comprises oppositely arranged P faces and N faces, and the packaging carrier comprises first, second and third conductive layers which are arranged in isolation; the P face comprises a ridge waveguide region and a tapered power amplification region which are arranged in sequence along the cavity length direction, and the P face is provided with a P face common electrode which is connected with the first conductive layer; the N face is provided with first and second N face electrodes which are arranged along the cavity length direction; a conductive path formed by the first conductive structure and the first N face electrode injects a first current into the ridge waveguide region, and a conductive path formed by the second conductive structure and the second N face electrode injects a second current into the tapered power amplification region, so as to compensate for the current diffusion effect between the ridge waveguide region and the tapered power amplification region. The application can solve the problem of thermal effect and reduce the difficulty of electrode separation.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more specifically to a semiconductor laser and its current control method. Background Technology

[0002] Under high-power operating conditions, the preferential growth and amplification of low beam quality modes, the mismatch in gain and polarization characteristics between the ridge region and the cone amplification region, and the mismatch between the optical field distribution and the spatial distribution of carrier injection / gain are key factors that limit the further improvement of output power and beam quality of semiconductor lasers.

[0003] In related technologies, by separating the ridge region electrode and the tapered amplification region electrode on the P-side, independent control and differentiated thermal management of the current in the two regions can be achieved, suppressing the amplification of higher-order side modes and stray modes, and improving beam quality. However, after separating the electrodes, when flip-chip bonding is performed with the P-side down, the corresponding soldering / metallization area on the heat sink side also needs to be isolated. This partitioned bonding structure is susceptible to the influence of the mismatch in the thermal expansion coefficients of the solder, chip, and heat sink material during thermal cycling, resulting in local stress concentration and shear strain. This may lead to chip warping, microcracks, or local defect propagation, adversely affecting polarization stability and beam quality. In extreme cases, it may even cause chip breakage during the flip-chip bonding process. Summary of the Invention

[0004] This invention provides a semiconductor laser and its current control method to solve the problems of partitioned welding and local stress concentration introduced by traditional P-side separated electrodes under flip-chip bonding conditions.

[0005] In a first aspect, the present invention provides a semiconductor laser, comprising an epitaxial structure and a packaging carrier; the epitaxial structure includes a P-plane and an N-plane disposed opposite to each other in the epitaxial growth direction, and the packaging carrier includes a first conductive layer, a second conductive layer, and a third conductive layer disposed in isolation, the first conductive layer being grounded; the P-plane includes a ridge waveguide region and a tapered power amplification region disposed sequentially along the cavity length direction, and a common electrode is disposed on the P-plane, the common electrode being connected to the first conductive layer through a solder layer; the N-plane has a first N-plane electrode and a second N-plane electrode arranged along the cavity length direction, the first N-plane electrode and the second N-plane electrode being electrically isolated, the first N-plane electrode corresponding to the ridge waveguide region and being connected to the third conductive layer through a first conductive structure, the second N-plane electrode corresponding to the tapered power amplification region and being connected to the second conductive layer through a second conductive structure; wherein, a first current is injected into the ridge waveguide region through a conductive path formed by the first conductive structure and the first N-plane electrode, and a second current is injected into the tapered power amplification region through a conductive path formed by the second conductive structure and the second N-plane electrode, to compensate for the current diffusion effect between the ridge waveguide region and the tapered power amplification region.

[0006] The semiconductor laser provided by this invention employs a P-side-down flip-chip package, which shortens the heat dissipation path, improves heat dissipation capacity, and suppresses power saturation and thermal degradation under high current. Simultaneously, the separation electrodes for the ridge waveguide region and the tapered power amplification region are moved from the P-side to the N-side. Structurally, this avoids the interface stiffness abrupt changes and solder morphology inconsistencies caused by the heat sink partitioning / insulation isolation trenches required for the P-side separation electrodes in P-down packaging. It also reduces local shear strain and stress concentration caused by thermal expansion coefficient mismatch, improving polarization stability, device consistency, and packaging yield, while reducing the risk of chip cracking. The P-side can be bonded to the package carrier with continuous electrodes to form a continuous bonding interface, reducing device thermal resistance and junction temperature, and improving device efficiency and reliability at high power.

[0007] Furthermore, by controlling the current injected into the ridge waveguide region and the tapered power amplification region, the current diffusion effect between the ridge waveguide region and the tapered power amplification region can be compensated. In addition, packaging and manufacturing are easier to standardize, reducing system complexity. The N-side electrodes can be led out in multiple ways through wire bonding, bump interconnection, etc., which has better process compatibility and large-scale manufacturing potential.

[0008] In one optional embodiment, the second N-face electrode includes a plurality of sub-electrodes arranged along the cavity length direction, forming a plurality of electrical injection sub-regions corresponding one-to-one with the plurality of sub-electrodes in the tapered power amplification region, with electrical isolation between any two adjacent sub-electrodes; the second conductive structure includes a plurality of sub-conductive structures corresponding one-to-one with the plurality of sub-electrodes, the sub-electrodes being connected to the corresponding sub-conductive structures, the plurality of sub-conductive structures being located on the second conductive layer, and the plurality of sub-conductive structures being isolated from each other; wherein, a target current is injected into the corresponding electrical injection sub-region through the sub-electrodes, at least two electrical injection sub-regions are injected with different target currents, and the sum of the target currents injected into the plurality of electrical injection sub-regions is the second current.

[0009] This invention divides the second N-face electrode into multiple sub-electrodes along the cavity length and injects them independently, so that the carrier injection in the conical power amplification region is spatially programmable. Compared with overall uniform injection, this segmented injection can finely compensate for local gain, alleviate the uneven gain depletion, local oversaturation and amplification of higher-order stray modes caused by the "mismatch between optical field distribution and gain distribution" in the conical power amplification region, thereby improving the beam quality under high power and delaying the occurrence of nonlinear effects.

[0010] In one alternative implementation, any two adjacent sub-electrodes are electrically isolated by a first isolation trench. The target parameters of the first isolation trench are determined based on the target currents corresponding to multiple electrically injected sub-regions. The target parameters include at least one of the following: trench width, trench depth, trench center position, and trench shape coefficient.

[0011] In one alternative implementation, the number of sub-electrodes is 2 to 10.

[0012] In one alternative implementation, the first N-sided electrode and the second N-sided electrode are electrically isolated by a second isolation tank.

[0013] In one optional embodiment, the second isolation trench is an isolation trench formed by a first metal layer spacing between the first N-side electrode and the second N-side electrode, an isolation trench formed by the first metal layer spacing and a groove formed by indentation from the N-side, an isolation trench formed by filling with an insulating medium, or an isolation region formed by ion implantation.

[0014] In one optional embodiment, the groove formed by the inward indentation of the N-face has a groove depth greater than 0 μm and a groove depth less than or equal to 150 μm, and the groove width of the second isolation groove is greater than or equal to 20 μm and a groove width less than or equal to 50 μm.

[0015] In a second aspect, the present invention provides a current control method for a semiconductor laser, wherein the semiconductor laser is the semiconductor laser described in the first aspect above or any corresponding embodiment thereof, a first conductive structure and a second conductive structure in the semiconductor laser are connected to a controller, the method is applied to the controller, and the method includes: acquiring a first current and a second current; injecting the first current into a ridge waveguide region through a conductive path formed by the first conductive structure and the first N-face electrode; and injecting the second current into a tapered power amplification region through a conductive path formed by the second conductive structure and the second N-face electrode to compensate for the current diffusion effect between the ridge waveguide region and the tapered power amplification region.

[0016] In one optional embodiment, injecting a second current into the conical power amplification region through a conductive path formed by the second conductive structure and the second N-face electrode includes: determining a current allocation weight corresponding to each of the plurality of electrical injection sub-regions according to a fitting function, wherein the second N-face electrode includes a plurality of sub-electrodes arranged along the cavity length direction, and the conical power amplification region forms a plurality of electrical injection sub-regions corresponding one-to-one with the plurality of sub-electrodes; determining a target current corresponding to each electrical injection sub-region according to the current allocation weight corresponding to each electrical injection sub-region and the second current, wherein the sum of the target currents injected into the plurality of electrical injection sub-regions is the second current; and injecting the target current into the corresponding electrical injection sub-region through a conductive path formed by the sub-conductive structure and the sub-electrodes.

[0017] In one alternative implementation, the expression for the fitting function is:

[0018] In the formula, Indicates the first i Current allocation weights for each injected sub-region This represents the lower bound bias coefficient of the fitted function. , This represents the slope coefficient of the fitted function, k > 0. The parameter representing the midpoint location of the fitted function, 1 ≤ < n , n Indicates the number of sub-regions injected with electricity. Indicates e An exponential function with base 0.

[0019] In one optional implementation, the target current for each injected sub-region is determined based on the current allocation weight and the second current corresponding to each injected sub-region, including: determining the target current for each injected sub-region using the following formula:

[0020] In the formula, Indicates the first i The target current corresponding to each injected sub-region, 1≤ i ≤ n , This indicates the second current. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the current flow in a semiconductor laser according to an embodiment of the present invention; Figure 2 This is a top view schematic diagram of a semiconductor laser according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the extensional structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of another semiconductor laser according to an embodiment of the present invention; Figure 5 This is a first schematic diagram of the electrical injection sub-region allocation according to an embodiment of the present invention; Figure 6 This is a second schematic diagram of the electrical injection sub-region allocation according to an embodiment of the present invention; Figure 7 This is a third schematic diagram of the electrical injection sub-region allocation according to an embodiment of the present invention; Figure 8 This is a schematic diagram illustrating the current density variation trend of multiple electro-injection sub-regions according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the fabrication process of the isolation groove according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the cross-sectional shape of the isolation groove according to an embodiment of the present invention; Figure 11 This is a schematic diagram illustrating the machining of a circular isolation groove according to an embodiment of the present invention; Figure 12 This is a schematic diagram of the average carrier density distribution in the xz plane without segmentation according to an embodiment of the present invention; Figure 13 This is a schematic diagram of the average photon density distribution in the xz plane without segmentation in an embodiment of the present invention; Figure 14 This is a schematic diagram of the average carrier density distribution in the xz plane during segmentation according to an embodiment of the present invention; Figure 15 This is a schematic diagram of the average photon density distribution in the xz plane during segmentation according to an embodiment of the present invention; Figure 16 This is a schematic diagram of a simulation model of a separate electrode according to an embodiment of the present invention; Figure 17 This is a schematic diagram of a segmented injection simulation model according to an embodiment of the present invention; Figure 18 This is a schematic diagram of a two-dimensional distribution of normal current density extracted from a QW surface according to an embodiment of the present invention.

[0023] Figure Descriptions: 100, Epitaxial structure; 101, Quantum well layer; 102, Ridge waveguide region; 103, Tapered power amplification region; 104, P-side common electrode; 105, First N-side electrode; 106, Second N-side electrode; 1061, Sub-electrode; 107, Second isolation trench; 108, Front-end surface grating structure; 109, Rear-end surface grating structure; 110, Destruction trench structure; 111, Tapered non-injection region; 112, First isolation trench; 200, Encapsulation carrier; 201, First conductive layer; 202, Second conductive layer; 203, Third conductive layer; 204, First conductive structure; 205, Second conductive structure; 2051, First electrode block; 300, Laser cutting equipment; 301, Laser. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the invention, not the entire structure.

[0025] In the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concepts of the present invention. Various structural schematic diagrams according to embodiments of the present invention are shown in the accompanying drawings. These drawings are not to scale, and some details are enlarged for clarity, and some details may be omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed. In the context of the present invention, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intermediate layer / element between them. Additionally, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element.

[0026] The semiconductor laser provided by this invention can be a master oscillator power amplifier (MOPA) semiconductor laser. The MOPA semiconductor laser consists of a refractive index-guided narrow ridge single-mode laser oscillator (MO) and a gain-guided cone amplifier (PA), and can be applied to fields such as materials processing, medical treatment, optical inspection, optical communication and lidar.

[0027] To suppress the amplification of low beam quality modes in semiconductor lasers under high-power operating conditions, early devices often employed a shared electrode to increase output power. However, this approach requires simultaneously increasing the injection current in the ridge and cone regions, which can easily lead to enhanced transverse mode competition and operating point instability, resulting in beam quality degradation. In contrast, the separate electrode scheme allows for independent control of the current in the two regions and differentiated thermal management, which helps suppress the amplification of higher-order modes and stray modes, and delays the onset of nonlinear effects and thermal degradation at high power.

[0028] Currently, there are two main ways to achieve separate electrodes: one is P-up packaging, where ridge waveguide electrodes and tapered amplification area electrodes are set on the P-side of the semiconductor laser to achieve independent current injection in the two areas; the other is P-down flip packaging, where the ridge waveguide electrodes and tapered amplification area electrodes are separated on the P-side, and an insulating isolation groove or partitioned welding structure is introduced on the heat sink side to avoid short circuits between the two electrodes during bonding and to ensure independent current injection.

[0029] Both of the above-mentioned solutions have certain limitations: P-side-up packaging results in a longer effective heat conduction path between the junction and the heat sink, limiting heat dissipation and making it more prone to junction temperature rise and output power thermal saturation under high current drive; while P-down packaging, if the ridge waveguide electrode and the tapered amplification area electrode are disconnected on the P-side, the corresponding soldering / metallization area on the heat sink side also needs to be partitioned and isolated. This partitioned bonding structure is susceptible to the effects of mismatched thermal expansion coefficients of the solder, chip, and heat sink materials during thermal cycling, resulting in localized stress concentration and shear strain, which may lead to chip warping, microcracks, or localized defect propagation, adversely affecting polarization stability and beam quality; in extreme cases, it may even cause chip breakage during flip bonding.

[0030] In view of this, the present invention provides a semiconductor laser and its current control method. While maintaining the efficient P-down heat dissipation path, it avoids the partitioned welding and localized stress concentration introduced by traditional P-side electrode separation under flip-chip bonding conditions by transferring the electrode separation of the main oscillation region (MO region) and the tapered power amplification region (PA region) from the P-side to the N-side. This reduces the risk of shear strain caused by thermal expansion mismatch and improves device reliability. In other words, the present invention solves the thermal effect problem, simplifies the difficulty of electrode separation, ensures continuous operation under high current, and simultaneously achieves electrode separation, improving the power and brightness of the tapered laser.

[0031] The semiconductor laser provided by the present invention will now be described in detail with reference to the accompanying drawings.

[0032] like Figure 1 , Figure 2 and Figure 3 As shown, the semiconductor laser includes an epitaxial structure 100 and a packaging carrier 200 (also called a heat sink). The epitaxial structure 100 includes a P-plane disposed opposite to the epitaxial growth direction Y (see...). Figure 3 (the upper surface) and N-side (see the ... lower surface) Figure 3 The lower surface of the package carrier 200 includes a first conductive layer 201, a second conductive layer 202 and a third conductive layer 203 that are isolated from each other. The first conductive layer 201 is grounded, and the second conductive layer 202 and the third conductive layer 203 are connected to an external circuit.

[0033] Specifically, the P-side can be the surface of the epitaxial structure 100 with a conductivity type of P, and the N-side can be the surface of the epitaxial structure 100 with a conductivity type of N. The epitaxial structure 100 may include, from top to bottom, an N-type substrate layer, an N-type confinement layer, an N-type waveguide layer, an active layer (including a quantum well layer 101), a P-type waveguide layer, a P-type confinement layer, and a P-type contact layer. Specifically, the P-side can be the surface of the P-type contact layer away from the P-type confinement layer, and the N-side can be the surface of the N-type substrate layer away from the N-type confinement layer.

[0034] like Figure 3 As shown, the P-side includes a ridge waveguide region 102 (also called the MO region) and a tapered power amplification region 103 (PA region) arranged sequentially along the cavity length direction Z. A common electrode 104 is provided on the P-side, which is connected to the first conductive layer 201 via a solder layer. During packaging, the P-side faces the packaging carrier 200. The common electrode 104 is used for P-down bonding to maintain a continuous and uniform bonding interface. The ridge waveguide region 102 is the area containing the ridge waveguide, and the tapered power amplification region 103 is the area containing the tapered waveguide amplification structure. The lateral width (i.e., the width in the lateral direction X) of the tapered waveguide amplification structure gradually increases along the cavity length direction Z.

[0035] like Figures 1 to 3 As shown, the N-side is provided with a first N-side electrode 105 and a second N-side electrode 106 arranged along the Z-direction of the cavity length. The first N-side electrode 105 and the second N-side electrode 106 are electrically isolated. The first N-side electrode 105 corresponds to the ridge waveguide region 102 and is connected to the third conductive layer 203 through a first conductive structure 204. The second N-side electrode 106 corresponds to the tapered power amplification region 103 and is connected to the second conductive layer 202 through a second conductive structure 205. The second conductive layer 202 and the third conductive layer 203 are connected to an external circuit structure (such as a controller).

[0036] like Figure 1 As shown, when the semiconductor laser is working, the controller injects a first current into the ridge waveguide region 102 through the conductive path formed by the first conductive structure 204 and the first N-face electrode 105, and injects a second current into the tapered power amplification region 103 through the second conductive structure 205 and the second N-face electrode 106. The controller can control the magnitude of the injected first and second currents to compensate for the current diffusion effect between the ridge waveguide region 102 and the tapered power amplification region 103.

[0037] Specifically, the projection of the ridge waveguide region 102 on the epitaxial growth direction Y is located within the first N-plane electrode 105, which is the N-plane ridge waveguide injection region. The projection of the tapered power amplification region 103 on the epitaxial growth direction Y is located within the second N-plane electrode 106, which is the N-plane tapered amplification injection region.

[0038] The first N-side electrode 105 and the second N-side electrode 106 can be electrically isolated by the second isolation trench 107. The present invention does not specifically limit the implementation of the second isolation trench 107. For example, the second isolation trench 107 can be an isolation trench formed by the first metal layer spacing between the first N-side electrode 105 and the second N-side electrode 106, an isolation trench formed by the first metal layer spacing and the groove formed by the inward indentation from the N-side, an isolation trench formed by the insulating medium filling the groove, a high-resistivity isolation region formed by ion implantation, or a combination thereof. Figure 3 Taking the second isolation trench 107 as an example, which is an isolation trench formed by the first metal layer spacing between the first N-side electrode 105 and the second N-side electrode 106.

[0039] The first conductive structure 204 refers to the conductive structure that connects the first N-side electrode 105 to the external circuit structure, and the second conductive structure 205 refers to the conductive structure that connects the second N-side electrode 106 to the external circuit structure. The present invention does not specifically limit the implementation form of the conductive structure. For example, the conductive structure can be wire bonding, bump interconnection, metal trace or a combination thereof. Figure 2 Taking the first conductive structure 204 and the second conductive structure 205 as metal leads as an example.

[0040] The semiconductor laser provided by this invention employs a P-side-down flip-chip package, shortening the heat dissipation path, improving heat dissipation capacity, and suppressing power saturation and thermal degradation under high current. Simultaneously, the separation electrodes of the ridge waveguide region 102 and the tapered power amplification region 103 are moved from the P-side to the N-side. This structurally avoids the interface stiffness abrupt changes and solder morphology inconsistencies caused by the heat sink partitioning / insulation isolation trenches required for the P-side separation electrodes in P-down packaging. It also reduces local shear strain and stress concentration caused by thermal expansion coefficient mismatch, improving polarization stability, device consistency, and packaging yield, while reducing the risk of chip cracking. The P-side can be bonded to the packaging carrier with continuous electrodes to form a continuous bonding interface, reducing device thermal resistance and junction temperature, and improving device efficiency and reliability at high power. Furthermore, packaging and manufacturing are easier to standardize, reducing system complexity. The N-side electrodes can be multi-ended through wire bonding, bump interconnection, etc., offering better process compatibility and scalable manufacturing potential.

[0041] For example, such as Figure 3 As shown, the epitaxial structure 100 also includes a front surface grating structure 108, a rear surface grating structure 109, a breaking groove structure 110, and a tapered non-injection region 111.

[0042] Specifically, the front-end surface grating structure 108 is disposed at the front end of the ridge waveguide, where the front end refers to the end of the ridge waveguide away from the tapered waveguide amplification structure in the cavity length direction Z. The edge of the front-end surface grating structure 108 is coated with a high-reflectivity film (reflectivity greater than or equal to 90%). The rear-end surface grating structure 109 is disposed at the rear end of the ridge waveguide, where the rear end refers to the end of the ridge waveguide closer to the tapered waveguide amplification structure in the cavity length direction Z. The edge of the rear-end surface grating structure 109 is coated with an anti-reflection film. The disrupting groove structure 110 is disposed on both sides of the ridge waveguide in the lateral direction X, and the tapered non-injection region 111 is disposed on both sides of the tapered power amplification region 103 in the lateral direction X, forming a tapered waveguide section without injected current.

[0043] The disrupting groove structure 110 is used to disrupt parasitic waveguides, reduce optical feedback, or reduce carrier leakage channels. In conjunction with the surface grating region (the region where the front-end surface grating structure 108 is located and the region where the rear-end surface grating structure 109 is located), it can stabilize MO mode selection and reduce parasitic oscillations caused by PA end face or structural reflection.

[0044] It should be noted that the P-plane is closer to the active layer and waveguide layer, resulting in a shorter propagation path and weaker lateral diffusion of current injected from the P-plane before reaching the quantum well. Therefore, it is easier to achieve independent injection control between the MO and PA regions. In this invention, when the separating electrode is transferred to the N-plane, the current needs to pass through the conductive N-type substrate before reaching the quantum well. Lateral diffusion may occur during this process, easily causing MO / PA crosstalk. The thickness of the N-type substrate is between 100 μm and 150 μm.

[0045] Furthermore, the present invention introduces a segmented current injection mechanism in the N-face conical power amplification region 103. On the one hand, it actively compensates for the current diffusion effect that may exist in the N-type substrate. On the other hand, it realizes fine control of carrier injection and gain distribution in the conical power amplification region 103, alleviates the gain space mismatch and mode competition problem under high power operation, and thus improves beam quality and output stability.

[0046] like Figure 4 As shown, the second N-face electrode 106 includes a plurality of sub-electrodes 1061 arranged along the Z-direction of the cavity length, so that the conical power amplification region 103 forms a plurality of electrical injection sub-regions corresponding one-to-one with the plurality of sub-electrodes 1061, and any two adjacent sub-electrodes are electrically isolated from each other; the second conductive structure 205 includes a plurality of sub-conductive structures corresponding one-to-one with the plurality of sub-electrodes 1061, the sub-electrodes are connected to the corresponding sub-conductive structures, the plurality of sub-conductive structures are all located on the second conductive layer 202, and the plurality of sub-conductive structures are isolated from each other, the sub-electrodes are connected to the controller through the corresponding sub-conductive structures, and the controller injects a target current into the corresponding electrical injection sub-region through the sub-electrodes, at least two electrical injection sub-regions are injected with different target currents, and the sum of the target currents injected into the plurality of electrical injection sub-regions is the second current.

[0047] The present invention does not specifically limit the implementation form of the sub-conductive structure. For example, the sub-conductive structure can also be wire bonding, bump interconnection, metal trace or a combination thereof. Figure 4 Taking a sub-conductive structure including a metal lead and a first electrode block 2051 as an example, an insulating layer is provided between the first electrode block 2051 and the second conductive layer 202. That is, multiple sub-conductive structures are isolated on the second conductive layer 202 through the insulating layer, and any two sub-conductive structures are electrically isolated from each other. Each electrical injection sub-region can be injected with current independently without interfering with each other.

[0048] Specifically, in order to compensate for current diffusion and alleviate the problems of gain mismatch, enhanced mode competition, and deteriorated beam quality caused by the mismatch between the optical field distribution and the gain spatial distribution in the conical power amplification region 103 under high power operating conditions, the present invention sets segmented electrodes (multiple sub-electrodes 1061) on the N-side of the conical power amplification region 103, so that the conical power amplification region 103 forms multiple independently adjustable electrical injection sub-regions along the cavity length direction Z, thereby achieving fine shaping of carrier injection and gain distribution in the conical power amplification region 103.

[0049] The tapered power amplification region 103 is divided along the cavity length direction Z (light propagation direction) into: n Each injection sub-region Each electrical injection sub-region A corresponding sub-electrode is set on the N-plane. Each sub-electrode is connected to the controller (drive end) via a sub-wire structure, thereby allowing different injection currents to be applied to each electrical injection sub-region. .

[0050] exist n= At 1 o'clock, if Figure 5 As shown, the second N-face electrode is a single piece, and the controller injects a first current into the ridge waveguide region 102 through the first N-face electrode. The controller injects a second current into the cone-shaped power amplification region 103 through the second N-face electrode. ;exist n = At 2 o'clock, if Figure 6 As shown, the second N-face electrode is divided into two sub-electrodes, and the tapered power amplification region 103 is also correspondingly divided into two electrical injection sub-regions. The controller injects a first current into the ridge waveguide region 102 through the first N-face electrode. The controller injects the first target current into the first electrical injection sub-region through a sub-electrode. A second target current is injected into the second electrical injection sub-region through another sub-electrode. ,and ;exist n= At 4 o'clock, if Figure 7As shown, the second N-face electrode is divided into 4 sub-electrodes, and the conical power amplification region 103 is also correspondingly divided into 4 electrical injection sub-regions. The controller injects a first current into the ridge waveguide region 102 through the first N-face electrode. The controller injects the target current into the corresponding electrical injection sub-region through four sub-electrodes. ,and .

[0051] The lengths of multiple sub-electrodes 1061 along the cavity length Z can be equal or unequal, and can also be determined based on the two-dimensional photon density distribution (i.e., optical field intensity distribution) of the semiconductor laser along the cavity length Z and the laser slow axis (lateral direction X). The length of the sub-electrodes 1061 along the cavity length Z is inversely proportional to the change in optical field intensity. Regions with rapid changes in optical field intensity are divided into finer segments (shorter sub-electrodes), while regions with gradual changes in optical field intensity are divided into coarser segments (longer sub-electrodes). Regions with lower photon density and greater sensitivity to injection can also be appropriately segmented. For example, a weighting function can be constructed, and the boundaries of each segment can be determined based on its cumulative distribution, thereby matching the electrical injection sub-region division with the actual optical field distribution and improving the effectiveness of gain shaping in the amplification region.

[0052] The number of sub-electrodes can be determined based on the length of the tapered power amplification region 103 along the cavity length direction Z. When the number is too small (e.g. n When =1), the tapered power amplification region 103 can only achieve rough two-stage control, which is difficult to effectively compensate for the gain mismatch along the cavity length direction within the tapered power amplification region 103; when the number is too large, although the theoretical control freedom increases, the length of each segment is too short, which easily approaches the current diffusion length, resulting in a decrease in the independence of adjacent segments, a significant increase in the number of N-side pads, isolation gaps, leads and drive channels, and an increase in packaging complexity.

[0053] Optionally, the number of sub-electrodes can be from 2 to 10, for example, 2, 5, 8 or 10, to avoid introducing excessive packaging complexity. Further, the number of sub-electrodes can be from 2 to 5.

[0054] Furthermore, in order to match the gain distribution of the conical power amplification region 103 with the actual optical field distribution, the present invention allocates injection current to each electric injection sub-region according to the two-dimensional photon density distribution.

[0055] Specifically, the controller is also used to acquire the two-dimensional photon density distribution of the semiconductor laser in the cavity length direction and the laser slow axis direction, and to acquire the total injection current of the tapered power amplification region; the controller is also used to determine the target current corresponding to each electric injection sub-region based on the two-dimensional photon density distribution and the total injection current, and to inject current into each electric injection sub-region based on the target current corresponding to each electric injection sub-region.

[0056] For example, the two-dimensional photon density distribution can be simulated in simulation software (such as COMSOL) based on a traveling-wave model. , Indicates the coordinate position in the lateral direction X. This represents the coordinate position along the Z-axis of the cavity length, and the total injected current in the tapered power amplification region. It can be determined based on the output power of the semiconductor laser.

[0057] In some optional embodiments, the step of the controller determining the target current corresponding to each electrically injected sub-region based on the two-dimensional photon density distribution and the total injection current may include the following steps: Step a1: Determine the weighting coefficients corresponding to each electrically injected photon region based on the two-dimensional photon density distribution.

[0058] Specifically, firstly, the equivalent total number of photons (or equivalent photons) corresponding to each electrically injected sub-region is determined based on the two-dimensional photon density distribution. i The equivalent total number of photons in each injected sub-region It can be as shown in formula (1):

[0059] In the formula, For the first i The integral domain of each injected photon region in the xz plane. For a two-dimensional model, the dimensions obtained from the above equation can be understood as the equivalent total number of photons per unit thickness of the emitting plane; since this invention uses their relative magnitudes for weight allocation, it does not affect the effectiveness and comparability of the piecewise current allocation. Mask function Characterizing the first i Each injected sub-region corresponds to an effective injection region (which can also be equivalent to an effective injection region including the effect of current diffusion). The effective injection region is defined by the designer; the equivalent total number of photons... Through the first i The average photon density level within the effective injection region corresponding to each electrically injected sub-region is characterized. The denominator of formula (1) is defined as the first... i Effective injection area of ​​each injection sub-region ,Right now .

[0060] After obtaining the equivalent total number of photons corresponding to each electrically injected sub-region, the normalization benchmark of the average photon density is determined by the following formula (2). :

[0061] A lower average photon density in an electrically injected sub-region indicates a weaker optical field and insufficient net gain, requiring higher injection to compensate. Conversely, a higher average photon density in an electrically injected sub-region necessitates a reduction in injection to suppress oversaturation and fringe enhancement in the later stages. Based on this, the ratio of the normalized average photon density to the equivalent total photon count corresponding to the electrically injected sub-region is determined as the weighting coefficient for that sub-region, i.e., the [missing value]. i The weighting coefficient corresponding to each injected sub-region As shown in formula (3):

[0062] Step a2: The target current for each electrical injection sub-region is determined by multiplying the total injection current by the weighting coefficient corresponding to each electrical injection sub-region.

[0063] In other embodiments, the current injection density of each injection sub-region can be determined based on a weighting coefficient and a baseline coefficient (normalized current density) for the current injection density; then, the target current for each injection sub-region is determined by multiplying the current injection density of each injection sub-region by the effective injection area. i Current injection density corresponding to each injection sub-region It can be shown in formula (4):

[0064] In the formula, A reference factor representing the current injection density. It can be shown in formula (5), that is , This refers to the total current in the cone-shaped power amplification region, i.e., the second current mentioned above.

[0065]

[0066] This invention divides the second N-face electrode into multiple sub-electrodes along the cavity length and injects them independently, so that the carrier injection in the conical power amplification region 103 is spatially programmable. Compared with uniform injection, this segmented injection can finely compensate for local gain, alleviate the uneven gain depletion, local oversaturation and amplification of higher-order stray modes caused by the "mismatch between optical field distribution and gain distribution" in the conical power amplification region 103, thereby improving the beam quality under high power and delaying the occurrence of nonlinear effects.

[0067] Furthermore, the injection weight of each sub-electrode is determined by the photon density spatial distribution obtained through the traveling wave model, and the target current corresponding to each sub-electrode is calculated under the constraint of total current conservation, so that the injection allocation matches the actual light intensity / stimulated emission intensity, thereby forming an engineering closed loop of "simulation-allocation-implementation". This mechanism can reduce the difficulty of empirical parameter tuning and improve the portability and consistency of different batches of devices and different packaging conditions.

[0068] In some alternative embodiments, the controller is further configured to determine the weighting coefficient corresponding to each electrical injection sub-region based on the fitting function, and to determine the target current corresponding to each electrical injection sub-region based on the weighting coefficient corresponding to each electrical injection sub-region and the total injection current of the tapered power amplification region. The controller is configured to inject current into each electrical injection sub-region based on the target current corresponding to each electrical injection sub-region.

[0069] Specifically, the fitting function can be a sigmoid function, the first of which is a sigmoid function. i The weighting coefficient corresponding to each injected sub-region , Indicates the first i The current distribution weights of each injected sub-region are obtained by fitting the Sigmoid function, as shown in Equation (6):

[0070] In the formula, This represents the lower bound bias coefficient of the Sigmoid function. , This represents the slope coefficient of the Sigmoid function, k > 0. The parameter representing the midpoint position of the Sigmoid function, 1 ≤ < n , n Indicates the number of sub-regions injected with electricity. Indicates e An exponential function with base Z. When the PA region is divided into 5 injection sub-regions along the cavity length Z (i.e., when the second N-face electrode includes 5 sub-electrodes). .

[0071] After determining the weighting coefficients, the target current for each electrical injection sub-region is determined by multiplying the weighting coefficient corresponding to each electrical injection sub-region by the total injection current of the tapered power amplification region. i The target current of each injected sub-region It can be shown in formula (7):

[0072] The slope of the fitted function increases rapidly at the front end of the tapered power amplification region (near the ridge waveguide region), and gradually approaches 0 at the rear end. The trend of current density variation from the front end to the rear end of the tapered amplification region along the cavity length Z is as follows: Figure 8 As shown, it first gradually increases and then tends to stabilize, where 0 on the horizontal axis represents the front end position of the conical magnification region.

[0073] For example, any two adjacent sub-electrodes can be electrically isolated by the first isolation trench 112. The present invention does not specifically limit the implementation of the first isolation trench 112. For example, the first isolation trench 112 can be an isolation trench formed by the metal layer spacing of the second N-side electrode 106, an isolation trench formed by the metal layer spacing of the second N-side electrode 106 and a groove formed by recessing from the N-side inward, an isolation trench formed by filling the groove with insulating medium, a high-resistivity isolation region formed by ion implantation, or a combination thereof. Figure 4 Taking the first isolation groove 112 as an example, which is an isolation groove formed by the spacing of the second N-face electrode 106.

[0074] Optionally, any two adjacent sub-electrodes are electrically isolated by a first isolation trench. The target parameters of the first isolation trench are determined based on the target currents corresponding to multiple electrically injected sub-regions. The target parameters include the trench width. trench depth Center position of the tank and groove coefficient At least one of the following: trench depth Affecting the remaining thickness of the bottom of the tank , This indicates the thickness of the N-type substrate layer.

[0075] Specifically, the center position of the trough The slot shape factor, representing the position relative to the boundary line between adjacent injected sub-regions, is determined based on the cross-sectional shape of the isolation slot (e.g., U-shaped, V-shaped, trapezoidal, etc.) and is used to characterize the equivalent isolation resistance of the isolation slot. The geometric parameters of the isolation slot affect the lateral equivalent isolation resistance between adjacent injected regions. Adjusting the geometry of the isolation trench helps suppress lateral current diffusion within the N-substrate. By aligning the geometry of the isolation trench with the target parameters, the effective injection current of each electrically injected sub-region in the quantum well layer can approach its respective set injection current (target current).

[0076] The first N-face electrode and the second N-face electrode are electrically isolated by the second isolation trench 107. The target parameters of the second isolation trench 107 are determined based on the target currents corresponding to multiple electrically injected sub-regions and the injection currents corresponding to the ridge waveguide region, so that the effective injection current of the ridge waveguide region in the quantum well layer also approaches the set injection current.

[0077] The depth of the second isolation trench 107 refers to the depth of the groove formed by the inward indentation from the N-face. The maximum depth is set according to the thickness of the N-type substrate layer. When the isolation trench is formed by the first metal layer between the first N-face electrode 105 and the second N-face electrode 106, the depth of the second isolation trench 107 is equivalent to 0 μm. The isolation effect can be achieved even if only the metal at the peeling trench position is not etched into the N-type substrate layer.

[0078] In one example, the groove formed by the inward indentation of the N-face has a depth greater than 0 μm and a depth less than or equal to 150 μm, and the width of the second isolation groove is greater than or equal to 20 μm and a width less than or equal to 50 μm. For example, the groove depth can be 1 μm, 40 μm, 80 μm, or 150 μm, etc., and the width of the second isolation groove 107 can be 20 μm, 30 μm, or 50 μm, etc.

[0079] With the width of the groove and groove depth The increase in thickness, and the remaining thickness at the bottom of the tank The reduction in [something] reduces the crosstalk current between regions; when the center position of the isolation slot is [something]... The isolation effect is best when aligned with the boundary line of adjacent injected sub-regions. Inter-region crosstalk current. Satisfy the following formula (8):

[0080] In the formula, This represents the lateral potential difference between adjacent injected sub-regions. The wider and deeper the slot, the greater the lateral equivalent isolation resistance and the smaller the crosstalk current between regions; the smaller the remaining thickness at the bottom of the slot, the narrower the lateral conductive channel and the smaller the crosstalk; the closer the center of the slot is to the current boundary line between adjacent regions, the more effectively it can suppress cross-region diffusion; the more conducive the slot shape is to increasing the length of the flow path (e.g., U-shape, circular arc bottom trapezoid, etc.), the more obvious the isolation effect.

[0081] For example, such as Figure 9 and Figure 10 As shown, the isolation trenches (first and second isolation trenches) can be fabricated using a laser cutting device 300 for micro / nano devices. The laser 301 can have a processing linewidth of 10μm to 20μm and a depth of up to 30μm. Deeper isolation trenches can be fabricated using high-frequency, high-energy pulse processing. After encapsulating the semiconductor laser in a packaging carrier, isolation trenches are fabricated on the N-side using a laser. Subsequently, wire bonding is performed to connect electrodes, achieving electrode separation and segmented implantation. The fabricated cross-section is shown below. Figure 10 As shown, the shape of the isolation groove can be rectangular, arched, stepped, etc.

[0082] The cross-sectional shape of the isolation groove is not limited in this invention. Figure 10This is for illustrative purposes only. The key point of the isolation trench is not its specific geometric profile, but rather its ability to create a high-resistance isolation band between the N-side electrodes, extend the lateral current diffusion path, and reduce inter-segment crosstalk. Therefore, any technology that achieves electrical isolation / diffusion suppression without compromising the chip's mechanical strength or active region structure falls within the scope of this invention.

[0083] Therefore, the shape of the isolation groove in this application can be arc-shaped, U-shaped, V-shaped, rectangular, trapezoidal, inverted trapezoidal, stepped, or equivalent deformations thereof. It is preferred to have a groove shape with a smooth bottom and no sharp stress concentration, so as to balance the electrical isolation effect and the mechanical reliability of the chip.

[0084] However, in actual processing, some arc shapes cannot be machined in one go, such as... Figure 11 The processing steps are the same as shown, with the arc edge being scanned repeatedly to form a superimposed trapezoidal structure.

[0085] This invention achieves independent injection of MO / PA by matching the conductivity of the epitaxial layer / substrate with the N-plane electrically isolated structure, so that the MO region and PA region still maintain significantly different longitudinal current density distributions at the quantum well location.

[0086] The present invention also provides a current control method for a semiconductor laser, wherein the semiconductor laser is the semiconductor laser provided in any of the above embodiments, a first conductive structure and a second conductive structure in the semiconductor laser are connected to a controller, and the current control method for the semiconductor laser is applied to the controller, the method comprising the following steps: Step S1201: Obtain the first current and the second current.

[0087] In step S1202, a first current is injected into the ridge waveguide region through the conductive path formed by the first conductive structure and the first N-face electrode.

[0088] In step S1203, a second current is injected into the tapered power amplification region through the conductive path formed by the second conductive structure and the second N-face electrode to compensate for the current diffusion effect between the ridge waveguide region and the tapered power amplification region.

[0089] Furthermore, the second N-face electrode includes multiple sub-electrodes arranged along the cavity length direction, so that the tapered power amplification region forms multiple electrical injection sub-regions corresponding one-to-one with the multiple sub-electrodes.

[0090] In some embodiments, step S1202 may include: Step b1: Determine the current allocation weight corresponding to each of the multiple electrical injection sub-regions based on the fitting function.

[0091] Specifically, the fitting function can be a sigmoid function.

[0092] For example, the fitting function can be as shown in formula (6), the first... i The weighting coefficient corresponding to each injected sub-region , Indicates the first i The current allocation weights for each injected sub-region are determined by fitting a function.

[0093] Step b2: Determine the target current for each electrical injection sub-region based on the current allocation weight and the second current corresponding to each electrical injection sub-region.

[0094] The sum of the target currents injected into multiple electrical injection sub-regions constitutes the second current.

[0095] For example, the target current corresponding to each electrical injection sub-region can be determined by formula (7).

[0096] Specifically, the product of the weighting coefficient corresponding to each electrical injection sub-region and the total injected current of the tapered power amplification region is the target current corresponding to the electrical injection sub-region, and the sum of the target currents injected into multiple electrical injection sub-regions is the second current.

[0097] Step b3: Inject the target current into the corresponding electrical injection sub-region through the conductive path formed by the sub-conductive structure and the sub-electrode.

[0098] The changing trends of the target currents corresponding to multiple electrical injection sub-regions can be seen as follows: Figure 8 As shown, it first gradually increases and then tends to stabilize.

[0099] In some optional embodiments, the method further includes the following steps: Step c1: Obtain beam quality evaluation indicators.

[0100] Step c2: Optimize the target current corresponding to each electrical injection sub-region according to the beam quality evaluation index, and inject current into the corresponding electrical injection sub-region according to the optimized target current.

[0101] Among them, beam quality evaluation indicators are used to characterize the quality of the beam output by the semiconductor laser after injection with the target current. Beam quality evaluation indicators may include output power, far-field sidelobes, and M 2 At least one of the factor and polarization extinction ratio.

[0102] Specifically, the optimization objective can be to achieve a threshold for beam quality evaluation indicators. An optimization algorithm (such as a genetic algorithm) can be used to optimize the target current corresponding to each electrically injected sub-region, resulting in an optimized target current. This embodiment further optimizes the injection current, which can further improve the mode stability and beam quality of the semiconductor laser at high power.

[0103] The effectiveness of the semiconductor laser provided by this invention is illustrated below with specific examples.

[0104] The structure of the semiconductor laser in this embodiment is as follows: Figures 1 to 3 As shown, the MO region has a width of 3µm and a length of 2000µm, the PA region has a cone angle of 6° and a length of 5000µm, and the total length is 7000µm. The MO and PA regions are injected in segments. The injection current density in the MO region is J1 = 5000A / cm², and the total uniform injection current in the PA region is I. PA =25A. A long cavity structure (total length 7000µm) is used for better heat dissipation in practical applications. A traveling wave model is used to simulate the semiconductor laser, and the simulation results are as follows: Figure 12 and Figure 13 As shown, Figure 12 N represents the average carrier density distribution in the xz plane without segmentation. avg (x, z) case, Figure 13 Sph represents the average photon density distribution in the xz plane without segmentation. avg (x, z) case.

[0105] After obtaining the simulation results, the current is allocated according to the current allocation principle provided above. In this embodiment, we take... n =5, that is, the PA is divided into 5 electrical injection sub-regions, each segment spaced 50µm apart, and different current densities are injected into each sub-region, while the total current remains constant. The effective area and total number of photons of the 5 electrical injection sub-regions are shown in Table 1, and the injection current corresponding to each electrical injection sub-region calculated based on Table 1 is shown in Table 2.

[0106] Table 1. Effective area and total photon count of the five electro-injection regions

[0107] Table 2. Current distribution in each segment

[0108] The optimized results are then output using a new segmented injection model, and the simulation results are as follows: Figure 14 and Figure 15 As shown, Figure 14 N represents the average carrier density distribution in the xz plane during segmentation. avg (x, z) case, Figure 15 Sph represents the average photon density distribution in the xz plane when segmented. avg (x, z) case.

[0109] The comparison before and after segmentation shows that the stripes / filamentation of the light field distribution inside the PA region is significantly reduced, the light field distribution is more uniform, the photon density distribution of the segmented injection is more concentrated in the central region, and the edges are smoother.

[0110] Simulation verification of N-plane injected current diffusion: To verify the feasibility of the N-face separated electrode structure and N-face segmented injection structure provided by the present invention, a three-dimensional current diffusion simulation model was established to calculate the normal current density distribution at the quantum well (QW) location. The MO region and PA region (and PA segmented region) were partitioned and integrated to obtain the effective injection current at QW in each region.

[0111] Simulation Model and Evaluation Indicators (1) Geometry and structure: such as Figure 16 As shown, the N-side of the model sequentially includes the MO region electrode, the isolation groove (or insulation gap), and the PA region electrode along the cavity length. The MO region has a length of 2000 μm, the isolation gap has a length of 20 μm, the PA region has a length of 5000 μm, and the lateral width of the PA gradually increases with the cavity length.

[0112] (2) Boundary conditions: The P-side is a continuous electrode and is set as a common return terminal (equipotential / grounded); the N-side is equipped with mutually electrically isolated MO injection electrodes and PA injection electrodes, and current is applied to them respectively. and The remaining outer surfaces are electrically insulated boundaries. Indicates the injected current in the MO region. This indicates the injected current in the PA region.

[0113] (3) Evaluation index: Extract the normal current density in the QW plane J n The effective injection current at QW is obtained by integrating over different regions. It can be shown in formula (9):

[0114] In the formula, Indicates the charge coefficient. , and These are the three orthogonal components of the normal current density. , and Let the unit component of the normal vector of the QW plane be denoted as . Represents the area of ​​a infinitesimal element on the QW plane. This indicates the current injection deviation in the MO region. This represents the effective injection current of the MO region in the QW plane. Indicates the current injection deviation in the PA region. This represents the effective injection current in the PA region into the QW plane.

[0115] Feasibility verification of N-face separated electrodes Injecting current into the N-plane MO region With the current injected into the PA region of the N-plane remaining constant at 0.3A, the current injected into the PA region of the N-plane is changed. (0A~25A), the partition current at QW is shown in Table 3: Table 3. Simulation results of separated electrodes

[0116] As can be seen from Table 3, the injection consistency in the PA region is good, with the deviation between the N-plane and the QW-plane being less than 5%. Under high current, the effective injection current of QW in the MO region is close to the set value, and as... The decrease in effective injection current (QW) in the MO region reflects the significant impact of current diffusion within a thick substrate at low current levels. However, since the target application of this invention is high-power MOPA-taper amplification, under typical MOPA operating mode (MO+PA simultaneously forward driven), the effective injection current in the MO region can be maintained within an usable range and decrease accordingly. The rapid improvement indicates that MO / PA separation injection is feasible under typical high-power MOPA operating conditions.

[0117] Feasibility verification of N-face segmented injection Furthermore, such as Figure 17 As shown, the N-side electrode in the PA region is divided into multiple sub-electrodes along the cavity length (e.g., 5 segments in Example 1). A set injection current (or current density) is applied to each segment, and the effective injection current of each segment is obtained by integrating the same segmented regions in the QW plane. Based on the principle that the lower the photon density (the darker the image), the more current compensation is applied, weights are assigned to the five PA segments. w i The current density of each segment was then calculated. J i With segmented current I i A non-uniform segmented injection was formed (the total is strictly 25A), and the specific data are given in Table 2. Simulations were performed under the conditions in Table 2, and the epitaxial (z-direction) component distribution of the QW surface current density is shown below. Figure 18 As shown.

[0118] Two-dimensional distribution of the normal current density (z-component) extracted from the QW plane reveals that the current density is higher near the cone corner edge than in the center (a typical current diffusion / current congestion phenomenon). Despite edge aggregation, the injection variation trend corresponding to the segment boundaries can still be observed along the cavity length, indicating that the segmented electrodes have tunable control over the injection distribution on the QW plane. Integrating each segment in the QW plane region yields the effective injection current for each segment, and the rate of change is listed in Table 4.

[0119] Table 4. Simulation results of segmented injection

[0120] From the results, we can see that I 21 I 24 I 25 The effective injection deviation of the QW surface from the port setting is within a small range of ±0.13% to -3.69%; while I 22 I 23 The deviations are relatively large (approximately -19.21% and -11.74%), with most segments achieving high consistency. Deviations in individual segments mainly stem from electrical diffusion and edge aggregation. However, the maximum deviation does not exceed 20%. With an N-layer thickness of approximately 150 μm, the segmented electrodes can still form a distinguishable and controllable injection distribution on the QW plane, and the injection error in the MO region remains within a controllable range of approximately -4%. The above analysis demonstrates that the N-plane segmented injection structure proposed in this invention is feasible within the conical amplification region and can serve as an electrical injection method for subsequent gain shaping and beam quality optimization.

[0121] In the description of this specification, the references to terms such as "this embodiment," "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples, without contradiction.

[0122] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0123] The above description does not provide detailed explanations of the technical aspects of each layer's patterning and etching. However, those skilled in the art should understand that various technical means can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be effectively combined.

[0124] The above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described above, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention.

[0125] Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention.

Claims

1. A semiconductor laser, characterized in that, Includes epitaxial structure and packaging carrier; The epitaxial structure includes a P-plane and an N-plane disposed opposite to each other in the epitaxial growth direction, and the encapsulation carrier includes a first conductive layer, a second conductive layer and a third conductive layer disposed in isolation, wherein the first conductive layer is grounded; The P-plane includes a ridge waveguide region and a tapered power amplification region arranged sequentially along the cavity length direction. The P-plane is provided with a common electrode, which is connected to the first conductive layer through a solder layer. The N-side is provided with a first N-side electrode and a second N-side electrode arranged along the cavity length direction. The first N-side electrode and the second N-side electrode are electrically isolated. The first N-side electrode corresponds to the ridge waveguide region and is connected to the third conductive layer through a first conductive structure. The second N-side electrode corresponds to the tapered power amplification region and is connected to the second conductive layer through a second conductive structure. Specifically, a first current is injected into the ridge waveguide region through the conductive path formed by the first conductive structure and the first N-face electrode, and a second current is injected into the tapered power amplification region through the conductive path formed by the second conductive structure and the second N-face electrode, in order to compensate for the current diffusion effect between the ridge waveguide region and the tapered power amplification region.

2. The semiconductor laser according to claim 1, characterized in that, The second N-face electrode includes a plurality of sub-electrodes arranged along the cavity length direction, so that the conical power amplification region forms a plurality of electrical injection sub-regions corresponding one-to-one with the plurality of sub-electrodes, and any two adjacent sub-electrodes are electrically isolated. The second conductive structure includes multiple sub-conductive structures that correspond one-to-one with the multiple sub-electrodes. The sub-electrodes are connected to the corresponding sub-conductive structures. The multiple sub-conductive structures are all located on the second conductive layer and are isolated from each other. Target current is injected into the corresponding electrical injection sub-region through the sub-electrodes. At least two electrical injection sub-regions have different target currents injected into them. The sum of the target currents injected into the multiple electrical injection sub-regions is the second current.

3. The semiconductor laser according to claim 2, characterized in that, Any two adjacent sub-electrodes are electrically isolated by a first isolation trench. The target parameters of the first isolation trench are determined based on the target currents corresponding to the plurality of electrically injected sub-regions. The target parameters include at least one of the following: trench width, trench depth, trench center position, and trench shape coefficient.

4. The semiconductor laser according to claim 2, characterized in that, The number of sub-electrodes is 2 to 10.

5. The semiconductor laser according to any one of claims 1 to 4, characterized in that, The first N-face electrode and the second N-face electrode are electrically isolated by a second isolation tank.

6. The semiconductor laser according to claim 5, characterized in that, The second isolation trench is an isolation trench formed by the first metal layer spacing between the first N-face electrode and the second N-face electrode, an isolation trench formed by the first metal layer spacing and the groove formed by the inward indentation from the N-face, an isolation trench formed by filling with an insulating medium, or an isolation region formed by ion implantation.

7. The semiconductor laser according to claim 6, characterized in that, The groove formed by the inward indentation of the N-face has a depth greater than 0 μm and a groove depth less than or equal to 150 μm, and the width of the second isolation groove is greater than or equal to 20 μm and a groove width less than or equal to 50 μm.

8. A current control method for a semiconductor laser, characterized in that, The semiconductor laser is the semiconductor laser according to any one of claims 1 to 7, wherein the first conductive structure and the second conductive structure in the semiconductor laser are connected to a controller, and the method is applied to the controller, the method comprising: Obtain the first current and the second current; The first current is injected into the ridge waveguide region through the conductive path formed by the first conductive structure and the first N-face electrode. The second current is injected into the tapered power amplification region through the conductive path formed by the second conductive structure and the second N-face electrode to compensate for the current diffusion effect between the ridge waveguide region and the tapered power amplification region.

9. The method according to claim 8, characterized in that, The injection of the second current into the tapered power amplification region through the conductive path formed by the second conductive structure and the second N-face electrode includes: The current allocation weight corresponding to each of the multiple electrical injection sub-regions is determined according to the fitting function. The second N-face electrode includes multiple sub-electrodes arranged along the cavity length direction, and the conical power amplification region is formed with multiple electrical injection sub-regions corresponding one-to-one with the multiple sub-electrodes. Based on the current allocation weight corresponding to each electrical injection sub-region and the second current, the target current corresponding to each electrical injection sub-region is determined, wherein the sum of the target currents injected into the plurality of electrical injection sub-regions is the second current; The target current is injected into the corresponding electrical injection sub-region through the conductive path formed by the sub-conductive structure and sub-electrode.

10. The method according to claim 9, characterized in that, The expression for the fitting function is: In the formula, Indicates the first i Current allocation weights for each injected sub-region This represents the lower bound bias coefficient of the fitted function. , This represents the slope coefficient of the fitted function, k >

0. The parameter representing the midpoint location of the fitted function, 1 ≤ < n , n Indicates the number of sub-regions injected with electricity. Indicates e An exponential function with base 0.

11. The method according to claim 10, characterized in that, The step of determining the target current corresponding to each injection sub-region based on the current allocation weight corresponding to each injection sub-region and the second current includes: The target current for each injected sub-region is determined using the following formula: In the formula, Indicates the first i The target current corresponding to each injected sub-region, 1≤ i ≤ n , This indicates the second current.

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