Surface-etched grating semiconductor laser with periodic pump structure

Abstract

The present application relates to a surface-etched grating semiconductor laser with a periodic pumping structure, the structure comprising a bottom doped dielectric layer, a multi-quantum well active layer, a ridge-shaped doped dielectric layer stacked in sequence, a periodic grating groove structure formed on the ridge-shaped doped dielectric layer, and a top surface electrical contact layer that forms an ohmic electrical contact with the electrical contact region between the grating grooves. Carriers are injected through the periodic electrical contact layer, flow through the electrical contact region, diffuse laterally after reaching the bottom of the grating grooves, and continue to diffuse to the multi-quantum well active layer. When the distribution is uniform, a laser based on refractive index modulation can be realized; when the distribution is non-uniform, additional gain modulation is introduced to realize a hybrid-modulated laser. The present application reduces the manufacturing cost of the semiconductor laser and improves its yield and reliability while effectively improving its performance stability.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor lasers and photon integration technology, in particular to a ridge laser structure. Background Art

[0002] Distributed feedback semiconductor lasers are widely deployed in optical communication systems due to their advantages, including excellent dynamic single-mode performance, compact size, and reliable light source. The basic elements of a laser consist of three parts: a gain medium, a cavity with a feedback mechanism, and an energy input. Distributed feedback lasers (DFB lasers) have two feedback mechanisms: periodic refractive index modulation and periodic gain (or loss) modulation.

[0003] Traditional distributed feedback semiconductor lasers (DFB) suffer from high manufacturing costs, low production yields, and poor reliability. Reducing manufacturing costs while maintaining DFB performance and improving yield and reliability is a pressing technical challenge. Summary of the Invention

[0004] In response to the problems in the above background technology, the present invention provides a ridge laser based on periodic pumping of a surface-etched grating, which reduces its manufacturing cost and improves its yield and reliability while effectively improving the performance of the semiconductor laser.

[0005] To achieve the above-mentioned objectives and other related objectives, the present application proposes a ridge laser structure, comprising a bottom doped dielectric layer, a multi-quantum well active layer, a ridge doped dielectric layer, a grating structure formed on the ridge doped dielectric layer, and a top surface electrode layer located on the top surface of the grating structure, which are stacked in sequence; the grating structure includes a plurality of grating grooves periodically spaced along the waveguide direction of the laser and periodic electrical contact regions between the grating grooves, and an insulating layer at least covering the sidewalls of the grating grooves is provided in the grating grooves; the top surface electrode layer forms an ohmic electrical contact with the top surface of the electrical contact region; wherein carriers injected through the top surface electrode layer flow downward through the electrical contact region and the ridge doped dielectric layer in sequence and then enter the multi-quantum well active layer, and the injected carriers in the multi-quantum well active layer present a specific carrier density distribution region due to the presence of the insulating grating grooves.

[0006] In the ridge laser structure in the above embodiment, a grating structure is formed on the ridge doped dielectric layer, including a plurality of grating grooves uniformly and periodically distributed along the waveguide direction of the laser and an electrical contact area defined by each grating groove. The grating groove is an electrical insulator, which limits the flow area of the injected current. When the distance between the bottom of the grating groove and the multi-quantum well active layer is small, the diffusion of the injected current at the bottom of the grating groove is limited, which causes the carrier density to fluctuate periodically along the grating groove in the direction of the laser cavity, resulting in a certain degree of gain modulation. Since the phase of the gain coupling in the present application is consistent with the phase of the refractive index coupling and will not cancel each other out, the gain modulation intensity and the refractive index modulation intensity and their relative ratio can be adjusted by setting the shape, size and grating order of the grating groove, thereby effectively improving the performance of the laser, improving its yield and reliability, and reducing its manufacturing cost.

[0007] In one embodiment, the maximum length of the orthographic projection of the bottom surface of the grating groove on the upper surface of the multi-quantum well active layer is less than or equal to the minimum distance between the bottom surface of the grating groove and the upper surface of the multi-quantum well active layer, so that the carriers in the specific carrier density distribution area are uniformly distributed under different injection currents.

[0008] In one embodiment, the maximum distance between the bottom surface of the grating groove and the upper surface of the multi-quantum well active layer is less than or equal to twice the minimum length of the positive projection of the bottom surface of the grating groove on the upper surface of the multi-quantum well active layer, so that the carriers in the specific carrier density distribution area are periodically non-uniformly distributed in the waveguide direction, forming gain modulation, and the modulation period of the gain modulation is consistent with the grating period.

[0009] In one embodiment, the refractive index modulation introduced by the grating structure and the gain modulation introduced by the top electrode layer have a preset phase relationship; the grating duty cycle, the grating order and the average distance between the bottom surface of the grating groove and the upper surface of the multi-quantum well active layer of the grating structure are all related to the gain modulation intensity or the refractive index modulation intensity of the ridge laser structure and their relative ratio, wherein the grating duty cycle is the ratio of the width of the unetched portion between the bottom surfaces of adjacent grating grooves to the grating period, and the grating period is the average spacing between adjacent grating grooves.

[0010] In one embodiment, the grating groove is formed in the ridge-shaped doped dielectric layer, and the depth of the grating groove is 0.1hh, where h is the thickness of the ridge-shaped doped dielectric layer. By adjusting the shape, size, and depth of the grating groove, under different injection currents, carriers injected through the top electrode layer sequentially flow through the electrical contact region and the bottom of the grating groove before laterally diffusing into the multi-quantum well active layer, forming a carrier distribution region with uniform carrier distribution, providing uniform pumping carriers for the laser, and effectively improving the performance and stability of the laser.

[0011] In one embodiment, the top electrode layer partially or completely covers the grating structure.

[0012] In one embodiment, the insulating layer includes a dielectric material and / or a polymer material.

[0013] In one embodiment, the doping type of the bottom doped dielectric layer is different from the doping type of the ridge-shaped doped dielectric layer.

[0014] In one embodiment, the ridge laser structure further includes at least one functional medium layer; the functional medium layer is formed on the side of the underlying doped medium layer away from the multi-quantum well active layer; functional elements are integrated in the functional medium layer, and the functional elements include at least one of passive components, active components, control components and mode conversion components.

[0015] The present application provides a surface-etched grating semiconductor laser with a periodic pumping structure, including any ridge laser structure described in the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to better describe and illustrate the embodiments and / or examples of the applications disclosed herein, reference may be made to the accompanying drawings. The additional details or examples used to describe the accompanying drawings should not be considered to limit the scope of the disclosed applications, the presently described embodiments and / or examples, and any of the presently understood best modes of these applications.

[0017] Figure 1 Shown is a schematic diagram of a cross-sectional structure of a ridge laser structure along a direction perpendicular to the waveguide of the laser in one embodiment of the present application;

[0018] Figure 2 Display as Figure 1 Schematic diagram of the cross-sectional structure along the AA' direction;

[0019] Figure 3 A schematic diagram showing the functional relationship between the grating coupling efficiency, the grating order, and the grating duty cycle provided in an embodiment of the present application is shown;

[0020] Figure 4-Figure 5 Shown are schematic diagrams of carrier injection patterns in different embodiments of the present application;

[0021] Figure 6 Shown is a schematic cross-sectional structure diagram of a ridge laser structure provided in another embodiment of the present application along a direction perpendicular to the waveguide of the laser;

[0022] Figure 7 Shown is a schematic flow chart of a method for preparing a ridge laser structure provided in one embodiment of the present application.

[0023] Description of reference numerals:

[0024] 10. Bottom doped dielectric layer; 20. Multi-quantum well active layer;

[0025] 30. Ridge-shaped doped dielectric layer; 31. Reflecting surface;

[0026] 40. Grating structure; 41. Grating groove; 42. Electrical contact region; 50. Ohmic electrical contact layer;

[0027] 60. Top electrode layer; 70. Functional dielectric layer;

[0028] 101. Insulation layer. DETAILED DESCRIPTION

[0029] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] It should be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it may be directly on, adjacent to, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there may be no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer, or part discussed below may be represented as a second element, component, region, layer, or part.

[0032] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein for convenience of description to describe the relationship of one element or feature shown in the figures to other elements or features. It should be understood that the spatially relative terms are intended to include different orientations of the device in use and operation in addition to the orientations shown in the figures. For example, if the device in the drawings is flipped, then the elements or features described as "under" or "beneath" or "beneath" the other elements will be oriented as "over" the other elements or features. Thus, the exemplary terms "under" and "under" may include both the upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or in other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0033] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present application. When used herein, the singular forms "a", "an", and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0034] Embodiments of the present invention are described herein with reference to cross-sectional views that are schematic illustrations of ideal embodiments (and intermediate structures) of the present invention. As such, variations from the shapes shown due to, for example, manufacturing techniques and / or tolerances are contemplated. Accordingly, embodiments of the present invention should not be limited to the specific shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. The regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the actual shapes of the regions of the device and are not intended to limit the scope of the present invention.

[0035] See also Figure 1-Figure 7 It should be noted that the diagrams provided in this embodiment are merely schematic illustrations of the basic concept of the present application. Although the diagrams only show components related to the present application and are not drawn according to the number, shape, and size of components in actual implementation, the type, quantity, and proportion of each component in actual implementation may be changed arbitrarily, and the component layout may also be more complex.

[0036] See also Figure 1-Figure 2 In one embodiment of the present application, a ridge laser structure is provided, comprising a bottom doped dielectric layer 10, a multi-quantum well active layer 20, a ridge doped dielectric layer 30 stacked in sequence, a grating structure 40 formed on the ridge doped dielectric layer 30, and a top surface electrode layer 60 located on the top surface of the grating structure 40; the grating structure 40 comprises a plurality of grating grooves 41 periodically distributed along the waveguide direction of the laser and an electrical contact region 42 defined by each grating groove 41, and an insulating layer 1 is provided in the grating groove 41 to at least cover the sidewalls of the grating groove 41. 01; an ohmic electrical contact layer 50 is formed between the top electrode layer 60 and the top surface of the electrical contact region 42; the ohmic electrical contact layer 50 is in contact with at least the top surface of the electrical contact region 42; wherein, carriers injected through the top electrode layer 60 and the periodic ohmic electrical contact layer 50 flow sequentially through the electrical contact region 42 and the bottom of the grating grooves 41 before beginning to diffuse laterally into the multi-quantum well active layer 20, causing the injected carriers in the multi-quantum well active layer 20 to exhibit a specific carrier density distribution region due to the presence of the insulating grating grooves 41, which is used to provide electrical pumping. Please note that the periodic intervals of the grating grooves 41 and the ohmic electrical contact layer 50 in this embodiment are not specifically limited to their periodic values and can be of equal periodicity or not.

[0037] As an example, see Figure 1-Figure 2A grating structure 40 can be formed within the ridge-doped dielectric layer 30, comprising a plurality of grating grooves 41 periodically spaced along the waveguide direction of the laser and an electrical contact region 42 defined by each grating groove 41. By utilizing the small distance between the bottom of the grating grooves 41 and the multi-quantum well active layer 20, the diffusion of the injected current is limited. This allows the carrier density to fluctuate periodically along the grating grooves 41 in the direction of the laser cavity, generating a certain degree of gain modulation. Because the phase of the gain coupling and the phase of the refractive index coupling in this application are consistent and do not cancel each other out, the gain modulation intensity and the refractive index modulation intensity can be adjusted by setting the order and duty cycle of the grating grooves 41, effectively improving the performance of the laser, reducing its manufacturing cost, and increasing its yield and reliability.

[0038] As an example, see Figure 1-Figure 2 By setting the distance between the bottom of the grating groove 41 and the multi-quantum well active layer 20, under different injection currents, the carriers injected through the top electrode layer 60 and the periodic ohmic electrical contact layer 50 flow through the electrical contact region 42 and the bottom of the grating groove 41 in sequence and then begin to diffuse laterally to the multi-quantum well active layer 20, forming a carrier distribution region with uniform carrier distribution, thereby providing a uniform pumping carrier distribution for the laser.

[0039] As an example, see Figure 1-Figure 2 Since the grating structure 40 includes a plurality of grating grooves 41 periodically distributed along the waveguide direction of the laser and an electrical contact area 42 defined by each grating groove 41, that is, the distribution of the grating grooves 41 is periodic, the grating duty cycle of the grating structure 40 is related to the gain modulation intensity of the ridge laser structure, wherein the grating period is the average spacing between adjacent grooves, and the grating duty cycle is the ratio of the electrical contact area 42 to the grating period; the grating order and grating duty cycle of the grating structure 40 are related to the refractive index modulation intensity of the ridge laser structure.

[0040] As an example, see Figure 1-Figure 2 The ohmic electrical contact layer 50 and the top electrode layer 60 may fully or partially cover the distributed grating 40 .

[0041] As an example, see Figure 1-Figure 2The grating groove 41 is formed in the ridge-shaped doped dielectric layer 30. The maximum length W of the orthographic projection of the bottom surface of the grating groove 41 on the upper surface of the multi-quantum well active layer 20 is less than or equal to the minimum distance d between the bottom surface of the grating groove 41 and the upper surface of the multi-quantum well active layer 20. This ensures that the carriers in a specific carrier density distribution area are uniformly distributed under different injection currents. In this case, the carriers injected through the top electrode layer 60 flow through the electrical contact region 42, reach the bottom of the grating groove 41, and then diffuse laterally, forming a uniform carrier density distribution within the multi-quantum well active layer 20. This uniform distribution is maintained under different injection currents, providing effective pumping for the laser.

[0042] As an example, see Figure 1-Figure 2 The maximum length W of the orthographic projection of the bottom surface of the grating groove 41 on the upper surface of the multi-quantum well active layer 20 is less than or equal to the minimum distance d between the bottom surface of the grating groove 41 and the upper surface of the multi-quantum well active layer 20, so that the carriers in the specific carrier density distribution area are periodically non-uniformly distributed in the waveguide direction, forming gain modulation, and the modulation period of the gain modulation is consistent with the grating period. In this case, the carriers injected through the periodic top surface electrode layer flow through the electrical contact area, and the diffusion of the injected current at the bottom of the grating groove is limited, which will cause the carrier density to fluctuate periodically along the grating groove in the direction of the laser cavity, resulting in a certain degree of gain modulation. Since the phase of the gain coupling generated by the gain modulation in this application is consistent with the phase of the refractive index coupling generated by the refractive index modulation, they will not offset each other to cause additional losses, and thus can effectively help suppress the nonlinear effect caused by the spatial burning of the simple refractive index coupling laser cavity and improve its instability introduced by external reflection, thereby improving the yield and reliability and reducing manufacturing costs. The laser in this embodiment has both gain modulation and refractive index modulation, and the ratio between the two directly affects the stability of the laser mode. In the present application, this ratio can be adjusted by the grating order, the grating duty cycle, and the shape and etching depth of the groove, wherein the grating duty cycle is the ratio of the electrical contact area (unetched portion) at the bottom of the grating groove to the grating period, and the grating period is the average spacing between adjacent grating grooves.

[0043] As an example, see Figure 1-Figure 2The grating groove 41 is formed in the ridge-shaped doped dielectric layer 30, and the depth of the grating groove 41 is 0.1hh, where h is the thickness of the ridge-shaped doped dielectric layer. The carriers in the carrier distribution region are uniformly distributed under different injection currents. By setting the shape, size, and depth of the grating groove, under different injection currents, the carriers injected through the top electrode layer flow sequentially through the electrical contact region and the bottom of the grating groove before laterally diffusing into the multi-quantum well active layer, forming a carrier distribution region with uniform carrier distribution, providing uniform pumping carriers for the laser, and effectively improving the performance and stability of the laser.

[0044] For example, the gain modulation intensity of the grating structure is inversely proportional to the grating duty cycle of the ridge laser structure, while the refractive index modulation intensity is further related to the grating order of the grating structure. The ratio of the gain and refractive index modulation intensities of the ridge laser structure can be adjusted by setting the grating order and adjusting the grating duty cycle of the grating structure.

[0045] As an example, see Figure 1-Figure 2 The insulating layer 101 may be configured to include a dielectric material and / or a polymer material. The insulating layer may include, but is not limited to, at least one of silicon nitride, silicon dioxide, silicon oxynitride, benzocyclobutene, polyimide, and spin-on-glass. When the grating trench is filled, a small amount of air, photoresist, or metal may remain, which does not significantly affect the grating function. Therefore, the insulating layer may include voids, residual photoresist, and / or residual metal.

[0046] As an example, see Figure 1-Figure 2 The doping type of the first doped dielectric layer 10 is different from the doping type of the ridge-shaped doped dielectric layer 30. For example, the doping type of the first doped dielectric layer 10 can be set to p-type and the doping type of the ridge-shaped doped dielectric layer 30 can be set to n-type; or the doping type of the first doped dielectric layer 10 can be set to n-type and the doping type of the ridge-shaped doped dielectric layer 30 can be set to p-type.

[0047] As an example, see Figure 3 , showing the relationship between the grating duty cycle of the grating structure 40 of a ridge laser structure and the refractive index modulation intensity under different grating orders. By adjusting the grating order and grating duty cycle of the grating structure 40, the refractive index modulation intensity of the ridge laser can be adjusted to achieve the desired ratio of the laser gain modulation intensity to the refractive index modulation intensity.

[0048] As an example, see Figure 4-Figure 5When the grating groove is formed in the ridge-shaped doped dielectric layer, the distance d from the bottom of the grating groove to the upper surface of the multi-quantum well active layer 20 can be set to a ratio of the width w of the bottom of the grating groove, that is, d / w. In one embodiment, the bottom of the grating groove is close to the multi-quantum well active layer, that is, the d / w ratio is 2 or any value below, so that the carrier distribution pattern formed by the current injected through the top periodic electrical contact layer is well maintained below the grating groove, modulating the carrier density distribution in the multi-quantum well active layer, and thus modulating the gain of the ridge laser. Figure 5 It can be found that the carriers are periodically modulated along the grating distribution direction. The higher the amplitude of the injected current, the greater the modulation degree of the carrier distribution. In another embodiment, the distance d between the bottom of the grating groove and the upper surface of the multi-quantum well active layer is larger than the width w of the bottom of the grating groove, that is, the d / w ratio is greater than 1 or any value above. This allows the carriers injected through the top periodic electrical contact layer to reach the bottom of the grating groove and then diffuse evenly along the grating distribution direction, thereby forming a uniform distribution of carriers in the multi-quantum well active layer, as shown in FIG. Figure 4 As shown in FIG, in this case, the carrier density distribution is uniform at different injection currents.

[0049] As an example, see Figure 6 The surface-etched grating ridge laser structure of the periodic electrode proposed in the present invention can also vertically integrate other functional component blocks, such as a functional dielectric layer 70 inserted below the underlying doped dielectric layer 10. The light generated by the laser can be guided to the corresponding functional components on the optional functional dielectric layer through a lossless (low) tapered structure. The functional component blocks of the functional dielectric layer 70 can include at least one of passive components, active components, control components, and mode conversion components. Passive components can include, but are not limited to, at least one of a spot size converter, a multiplexer, and a demultiplexer. Active components can include, but are not limited to, at least one of an electro-absorption modulator or a semiconductor amplifier. Control components can include, but are not limited to, at least one of a variable optical attenuator and an optical switch.

[0050] As an example, the present application provides a surface-etched grating semiconductor laser with a periodic pumping structure, including any ridge laser structure described in the embodiments of the present application. By forming a grating structure including a plurality of grating grooves periodically distributed along the waveguide direction of the laser and an electrical contact area defined by each grating groove on a ridge-doped dielectric layer, the distance between the bottom of the grating groove and the multi-quantum well active layer is small, and the diffusion of the injected current is limited, so that in the direction of the laser cavity, the carrier density fluctuates periodically with the grating groove, resulting in a certain degree of gain modulation. Since the phase of the gain coupling in the present application is consistent with the phase of the refractive index coupling and will not cancel each other out, the gain modulation intensity and the refractive index modulation intensity can be adjusted by setting the shape, size and number of the grating grooves, thereby effectively improving the performance of the laser, reducing its manufacturing cost, and improving its yield and reliability.

[0051] See also Figure 7 , the present application provides a method for preparing a ridge laser structure, comprising:

[0052] Step S110, providing a substrate and a device epitaxial structure, wherein the device epitaxial structure includes an optional functional dielectric layer, a bottom doped dielectric layer, a multi-quantum well active layer, and a ridge doped dielectric layer stacked in sequence;

[0053] Step S120, forming a grating structure on the ridge-shaped doped dielectric layer, the grating structure comprising a plurality of grating grooves periodically spaced along a waveguide direction of the laser, an electrical contact region defined by each grating groove, and an insulating layer formed in the grating grooves to at least cover the sidewalls of the grating grooves;

[0054] In step S130, a top surface electrode layer is formed, and the top surface electrode layer forms an ohmic electrical contact region with at least the top surface of the electrical contact region, so that the carriers injected through the top surface electrode layer flow through the periodic electrical contact region in sequence, pass through the bottom of the grating groove, and then diffuse laterally to the multi-quantum well active layer, forming a carrier distribution region for providing pumping.

[0055] Please note that the above embodiment is only for illustrative purposes and does not mean limitation of the application. It should be understood that, unless clearly stated herein, the execution of the steps does not have strict order restrictions, and these steps can be performed in other orders. Moreover, at least a portion of the steps may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these sub-steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of other steps or sub-steps or stages of other steps.

[0056] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0057] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. As long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. The scope of protection of the patent application shall be determined by the appended claims.

Claims

1. A ridge laser structure, characterized in that: The device comprises a bottom doped dielectric layer, a multi-quantum well active layer, a ridge-shaped doped dielectric layer, a grating structure formed in the ridge-shaped doped dielectric layer, and a top surface electrode layer located on the top surface of the grating structure. The grating structure includes a plurality of grating grooves periodically distributed along the waveguide direction of the laser and periodic electrical contact regions between the grating grooves, and an insulating layer at least covering the sidewalls of the grating grooves is provided in the grating grooves; the orthographic projection of the ridge-shaped doped dielectric layer on the top surface of the multi-quantum well active layer is located inside the top surface of the multi-quantum well active layer; the grating grooves do not penetrate the sidewalls of the ridge-shaped doped dielectric layer, and the ridge-shaped doped dielectric layer between adjacent grating grooves is used to form the electrical contact region; The top surface electrode layer with a flush top surface forms an ohmic electrical contact with the top surface of the periodic electrical contact area; Among them, the carriers injected through the top electrode layer flow downward through the electrical contact area and the ridge-type doped medium layer in sequence and then enter the multi-quantum well active layer. The injected carriers of the multi-quantum well active layer present a specific carrier density distribution area due to the presence of the insulating grating grooves; the refractive index modulation introduced by the grating structure and the gain modulation introduced by the top electrode layer are consistent in phase.

2. The ridge laser structure according to claim 1, wherein: The maximum length of the orthographic projection of the bottom surface of the grating groove on the upper surface of the multi-quantum well active layer is less than or equal to the minimum distance between the bottom surface of the grating groove and the upper surface of the multi-quantum well active layer, so that the carriers in the specific carrier density distribution area are uniformly distributed under different injection currents.

3. The ridge laser structure according to claim 1, wherein: The maximum distance between the bottom surface of the grating groove and the upper surface of the multi-quantum well active layer is less than or equal to twice the minimum length of the positive projection of the bottom surface of the grating groove on the upper surface of the multi-quantum well active layer, so that the carriers in the specific carrier density distribution area are periodically non-uniformly distributed in the waveguide direction, forming gain modulation, and the modulation period of the gain modulation is consistent with the grating period.

4. The ridge laser structure according to claim 1, wherein: The grating duty cycle, grating order and average distance between the bottom surface of the grating groove and the upper surface of the multi-quantum well active layer of the grating structure are all related to the gain modulation intensity or refractive index modulation intensity of the ridge laser structure, wherein the grating duty cycle is the ratio of the width of the unetched material between the bottom surfaces of adjacent grating grooves to the grating period, and the grating period is the average spacing between adjacent grating grooves.

5. The ridge laser structure according to any one of claims 1 to 4, characterized in that: The grating groove is formed in the ridge-shaped doped dielectric layer, and the depth of the grating groove is 0.1hh; Wherein, h is the thickness of the ridge-shaped doped dielectric layer.

6. The ridge laser structure according to any one of claims 1 to 4, characterized in that: The top electrode layer partially or completely covers the grating structure.

7. The ridge laser structure according to any one of claims 1 to 4, characterized in that: The insulating layer includes a dielectric material and / or a polymer material.

8. The ridge laser structure according to any one of claims 1 to 4, characterized in that: The doping type of the bottom doped dielectric layer is different from the doping type of the ridge-shaped doped dielectric layer.

9. The ridge laser structure according to any one of claims 1 to 4, characterized in that: Also includes at least one functional medium layer; The functional dielectric layer is formed on a side of the underlying doped dielectric layer away from the multi-quantum well active layer; Functional elements are integrated in the functional medium layer, and the functional elements include at least one of passive components, active components, control components and mode conversion components.

10. A surface-etched grating semiconductor laser with a periodic pump structure, characterized in that: The ridge laser structure comprises the ridge laser structure according to any one of claims 1 to 9.

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