Lasers and their fabrication methods

Abstract

This application provides a laser and its fabrication method, relating to the field of semiconductor technology, to address the problems of small core area and high fabrication cost in single-mode VCSELs. The laser includes: a first distributed Bragg mirror layer, an active layer disposed on the first distributed Bragg mirror layer, a second distributed Bragg mirror layer and a third distributed Bragg mirror layer disposed on the side of the active layer away from the first distributed Bragg mirror layer, and electrodes. The second distributed Bragg mirror layer surrounds the third distributed Bragg mirror layer, and the refractive index of the third distributed Bragg mirror layer is lower than that of the second distributed Bragg mirror layer. The electrodes provide current to the active layer to generate photons; a light-emitting port is provided at the end of the third distributed Bragg mirror layer away from the first distributed Bragg mirror layer.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a laser and a method for fabricating the same. Background Technology

[0002] Vertical cavity surface emitting lasers (VCSELs) have advantages such as small size, low power consumption, high coupling efficiency, large modulation bandwidth, high efficiency, and good stability, and are widely used in data communication, sensing, lidar, materials processing and other fields.

[0003] Among them, single-mode VCSELs have advantages such as small spectral width, small beam divergence angle, and near-Gaussian beam distribution, which are conducive to increasing the signal transmission distance, improving its coupling efficiency with optical fiber, and improving the accuracy, sensitivity, speed and efficiency of application systems.

[0004] However, traditional single-mode VCSELs require extremely small core regions to ensure single-mode operation and cannot be mass-produced. Summary of the Invention

[0005] This application provides a laser and its fabrication method to address the problems of small core area size and high fabrication cost in single-mode VCSELs.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] A first aspect of this application provides a laser, including a first distributed Bragg reflector layer, an active layer disposed on the first distributed Bragg reflector layer, a second distributed Bragg reflector layer and a third distributed Bragg reflector layer disposed on the side of the active layer away from the first distributed Bragg reflector layer, and electrodes. The second distributed Bragg reflector layer is disposed around the third distributed Bragg reflector layer, and the refractive index of the third distributed Bragg reflector layer is less than that of the second distributed Bragg reflector layer. The electrodes are used to provide current to the active layer to generate photons. A light-emitting port is provided at the end of the third distributed Bragg reflector layer away from the first distributed Bragg reflector layer.

[0008] The laser provided in this application comprises a first distributed Bragg mirror layer, a second distributed Bragg mirror layer, a third distributed Bragg mirror layer, and an active layer forming the resonant cavity of the laser. The active layer serves as the light-emitting region of the laser, the first distributed Bragg mirror layer serves as the total internal reflection mirror of the laser, and the second and third distributed Bragg mirror layers serve as the light-emitting mirrors of the laser. The second distributed Bragg mirror layer forms the outer region of the laser, and the third distributed Bragg mirror layer forms the core region of the laser.

[0009] After the electrodes are connected to the power supply, current is injected into the active layer to generate electrons and holes. At this point, the electrons and holes in the active layer recombine to produce photons, and stimulated emission occurs simultaneously. The photons reflect back and forth between the first and third distributed Bragg reflector layers, and generate stimulated emission with stimulated particles, continuously repeating the light amplification process. This enhances the photons along the direction from the first to the third distributed Bragg reflector layer, ultimately forming a laser beam, which is output from the light outlet of the third distributed Bragg reflector layer.

[0010] Since the refractive index of the second distributed Bragg mirror layer is greater than that of the third distributed Bragg mirror layer, the higher-order mode laser will leak from the interface between the second and third distributed Bragg mirror layers to the second distributed Bragg mirror layer, thereby suppressing the higher-order mode and allowing the fundamental mode laser to be emitted from the output port of the third distributed Bragg mirror layer, thus realizing the single-mode operation of the laser.

[0011] The refractive index of the second distributed Bragg mirror layer in the laser provided in this application is greater than that of the third distributed Bragg mirror layer, and the refractive index of the outer region of the laser is much greater than that of the core region. This results in a stronger anti-waveguide effect and stronger suppression of higher-order modes, enabling the laser to operate in single-mode. Therefore, the laser provided in this application does not need to limit the aperture size of the current injection layer or the size of the core region to achieve single-mode operation, thus enabling a laser with a larger core region.

[0012] In some embodiments, the second distributed Bragg reflector layer is a multilayer semiconductor layer stacked together. The second distributed Bragg reflector layer, serving as the outer region of the laser, has a relatively high refractive index.

[0013] In some embodiments, the third distributed Bragg reflector layer is a multilayer dielectric layer stacked together. The equivalent refractive index of the multilayer dielectric layer is lower than that of the multilayer semiconductor layer; therefore, the refractive index of the third distributed Bragg reflector layer is lower than that of the second distributed Bragg reflector layer. As the core region of the laser, the third distributed Bragg reflector layer has a lower refractive index.

[0014] In some embodiments, the electrode includes a first electrode and a second electrode; the first electrode is disposed on the side of the first distributed Bragg reflector layer away from the second distributed Bragg reflector layer; the second electrode is disposed on the side of the second distributed Bragg reflector layer away from the first distributed Bragg reflector layer. The first electrode and the second electrode are respectively connected to the positive and negative terminals of a power supply to provide current to the active layer.

[0015] In some embodiments, the laser further includes a first current diffusion layer and a second current diffusion layer; the first current diffusion layer is located between the active layer and the first distributed Bragg mirror layer, and the second current diffusion layer is located between the active layer and the second distributed Bragg mirror layer; the second distributed Bragg mirror layer and the second current diffusion layer form a stepped shape; the active layer and the first current diffusion layer form a stepped shape; the electrodes include a third electrode and a fourth electrode; the third electrode is disposed on the first current diffusion layer and surrounds the active layer; the fourth electrode is disposed on the second current diffusion layer and surrounds the second distributed Bragg mirror layer. In this embodiment, disposing the third electrode on the first current diffusion layer and the fourth electrode on the second current diffusion layer reduces the injected current path.

[0016] In some embodiments, the semiconductor layer material includes at least one of gallium arsenide, gallium nitride, or indium phosphide. The equivalent refractive index of the multilayer semiconductor layer material is greater than that of the multilayer dielectric layer material; therefore, the refractive index of the second distributed Bragg mirror layer is greater than that of the third distributed Bragg mirror layer.

[0017] In some embodiments, the dielectric layer material includes at least one of silicon oxide, hafnium oxide, or silicon nitride. The equivalent refractive index of the multilayer semiconductor layer material is greater than the equivalent refractive index of the multilayer dielectric layer material; therefore, the refractive index of the second distributed Bragg mirror layer is greater than the refractive index of the third distributed Bragg mirror layer.

[0018] In some embodiments, the laser further includes an oxide confinement layer and a current injection layer; the oxide confinement layer is disposed around the current injection layer, located between the second distributed Bragg mirror layer and the active layer, and the current injection layer is located between the third distributed Bragg mirror layer and the active layer. The oxide confinement layer is used to confine the optical waveguide, and the current is concentrated by the current injection layer to increase the current density, thereby improving the uniformity of laser emission.

[0019] In some embodiments, the top surface of the third distributed Bragg mirror layer away from the first distributed Bragg mirror layer is flush with the top surface of the second distributed Bragg mirror layer away from the first distributed Bragg mirror layer. This results in good light output from the laser's output port.

[0020] In some embodiments, the top surface of the third distributed Bragg mirror layer, away from the first distributed Bragg mirror layer, is lower than the top surface of the second distributed Bragg mirror layer, away from the first distributed Bragg mirror layer. This design is simple to operate and easy to implement.

[0021] A second aspect of this application provides a method for fabricating a laser, comprising: forming a first distributed Bragg mirror layer, an active film, and a second distributed Bragg mirror film stacked sequentially; etching the second distributed Bragg mirror film to form a second distributed Bragg mirror layer, the second distributed Bragg mirror layer having a ring structure; forming a third distributed Bragg mirror layer in a region surrounded by the second distributed Bragg mirror layer; the refractive index of the third distributed Bragg mirror layer being less than the refractive index of the second distributed Bragg mirror layer; and forming an electrode for providing current to the active film.

[0022] The laser fabrication method provided in this application comprises a first distributed Bragg mirror layer, a second distributed Bragg mirror layer, a third distributed Bragg mirror layer, and an active layer constituting the resonant cavity of the laser. The active layer serves as the light-emitting region of the laser, the first distributed Bragg mirror layer serves as the total internal reflection mirror of the laser, and the second and third distributed Bragg mirror layers serve as the light-emitting mirrors of the laser. Specifically, the second distributed Bragg mirror layer serves as the outer region of the laser, and the third distributed Bragg mirror layer serves as the core region of the laser.

[0023] After the electrodes are connected to the power supply, current is injected into the active layer to generate electrons and holes. At this point, the electrons and holes in the active layer recombine to produce photons, and stimulated emission occurs simultaneously. The photons reflect back and forth between the first and third distributed Bragg reflector layers, and generate stimulated emission with stimulated particles, continuously repeating the light amplification process. This enhances the photons along the direction from the first to the third distributed Bragg reflector layer, ultimately forming a laser beam, which is output from the light outlet of the third distributed Bragg reflector layer.

[0024] Since the refractive index of the second distributed Bragg mirror layer is greater than that of the third distributed Bragg mirror layer, the higher-order mode laser will leak from the interface between the second and third distributed Bragg mirror layers to the second distributed Bragg mirror layer to suppress the higher-order mode, so that the fundamental mode laser will be emitted from the output port of the third distributed Bragg mirror layer, thus realizing the single-mode operation of the laser.

[0025] The laser fabrication method provided in this application involves a second distributed Bragg mirror layer with a refractive index greater than that of the third distributed Bragg mirror layer. Therefore, the refractive index of the outer region of the laser is significantly greater than that of the core region, resulting in a stronger anti-waveguide effect and stronger suppression of higher-order modes, enabling single-mode operation. Thus, the laser fabrication method of this application eliminates the need to limit the aperture size of the current injection layer or the size of the core region to achieve single-mode operation, enabling the fabrication of lasers with larger core regions.

[0026] In some embodiments, the third distributed Bragg reflector layer is formed in the area surrounded by the second distributed Bragg reflector layer using a vapor deposition process. This method is simple to operate and does not introduce optical loss or material defects.

[0027] In some embodiments, the electrode includes a first electrode and a second electrode; the first electrode is formed on the side of the first distributed Bragg reflector layer away from the second distributed Bragg reflector layer; the second electrode is formed on the side of the second distributed Bragg reflector layer away from the first distributed Bragg reflector layer. The first electrode and the second electrode are respectively connected to the positive and negative terminals of a power supply to provide current to the active layer.

[0028] In some embodiments, the active film is a multilayer semiconductor film stacked together. The semiconductor film closest to the second distributed Bragg mirror layer in the multilayer semiconductor film is locally oxidized to form an oxide confinement layer and a current injection layer. The oxide confinement layer is disposed around the current injection layer. The oxide confinement layer is located between the second and first distributed Bragg mirror layers, and the current injection layer is located between the third and first distributed Bragg mirror layers. Oxidizing the active film to form the oxide confinement layer is a simple and easy-to-implement process, avoiding lattice defects introduced by proton injection technology. Furthermore, the oxide confinement layer confines the optical waveguide, and the current injection layer concentrates the current, increasing the current density and thus improving the uniformity of laser emission.

[0029] In some embodiments, the fabrication method further includes: forming a first current diffusion film on the first distributed Bragg mirror layer before forming the active film; forming a second current diffusion film on the side of the active film away from the first distributed Bragg mirror layer after forming the active film; and before locally oxidizing the semiconductor film, the fabrication method further includes: etching the second current diffusion film and the active film to form an active layer and a second current diffusion layer; the first current diffusion film serves as the first current diffusion layer of the laser; the active layer and the second current diffusion layer are stepped; while etching the center of the second distributed Bragg mirror film, the edges of the second distributed Bragg mirror film are also etched to make the second distributed Bragg mirror layer and the second current diffusion layer stepped. The active layer and the first current diffusion layer are stepped, and the second distributed Bragg mirror layer and the first current diffusion layer are stepped, so that electrodes can be subsequently formed on the first current diffusion layer and the second current diffusion layer.

[0030] In some embodiments, after forming the first current diffusion layer and the second current diffusion layer, the fabrication method further includes: forming a third electrode and a fourth electrode; the third electrode is disposed on the first current diffusion layer and surrounding the active layer; the fourth electrode is disposed on the second current diffusion layer and surrounding the second distributed Bragg reflector. The placement of the third electrode on the first current diffusion layer and the fourth electrode on the second current diffusion layer can reduce the injection current path.

[0031] A third aspect of the embodiments of this application provides a detection device, including a laser and a receiver provided in any of the first aspects; the receiver is used to receive the light signal emitted by the laser.

[0032] The detection device provided in the third aspect of the embodiments of this application includes the laser of any one of the first aspects, and its beneficial effects are the same as those of the laser, which will not be repeated here. Attached Figure Description

[0033] Figure 1 This application provides a schematic diagram of the structure of a radar system according to an embodiment of the present application.

[0034] Figure 2 This is a schematic diagram of the structure of a laser provided in an embodiment of this application;

[0035] Figure 3 A schematic flowchart illustrating a method for fabricating a laser, as provided in an embodiment of this application;

[0036] Figures 4A-4Q This is a schematic diagram illustrating a method for fabricating a laser according to an embodiment of this application.

[0037] Figure 5A A top view of a laser provided in an embodiment of this application;

[0038] Figure 5B for Figure 5A A cross-sectional view along the A1-A2 direction;

[0039] Figure 5C A schematic diagram of the refractive index distribution of a laser provided in an embodiment of this application;

[0040] Figure 5D for Figure 5A Another sectional view along the A1-A2 direction;

[0041] Figure 5E A top view of a laser provided in an embodiment of this application;

[0042] Figure 5F A top view of a laser provided in an embodiment of this application;

[0043] Figure 6 This is a schematic diagram of the structure of another laser provided in an embodiment of this application;

[0044] Figure 7 This is a schematic diagram of the structure of another laser provided in an embodiment of this application;

[0045] Figure 8 This is a schematic diagram of the structure of another laser provided in an embodiment of this application;

[0046] Figure 9 A schematic flowchart illustrating a laser operating method provided in an embodiment of this application;

[0047] Figure 10A A schematic diagram of a high-order mode propagation path of a laser provided in an embodiment of this application;

[0048] Figure 10B This is a schematic diagram of the fundamental mode distribution of a laser provided in an embodiment of this application;

[0049] Figure 11 A schematic flowchart illustrating another method for fabricating a laser provided in this application embodiment;

[0050] Figures 12A-12C A schematic diagram illustrating the process of another laser fabrication method provided in this application embodiment;

[0051] Figure 13A A top view of a laser provided in an embodiment of this application;

[0052] Figure 13B for Figure 13A A cross-sectional view along the B1-B2 direction. Attached Figure Description

[0054] 1-Radar system; 2-Signal transmitting module; 3-Signal receiving module; 4-Optical path adjustment module; 5-Data processing module; 6-Object under test; 21-Emitting optical path; 31-Reflecting optical path; 100-Laser; 110-First distributed Bragg reflector layer; 120-Second distributed Bragg reflector layer; 120'-Second distributed Bragg reflector film; 130-Third distributed Bragg reflector layer; 210-First current diffusion layer; 210'-First current diffusion film; 220-Second current diffusion layer; 220'-Second current diffusion film; 310-Active layer; 310'-Active film; 310"-Active film layer; 311-Oxidation confinement layer; 312-Current injection layer; 410'-First electrode; 420'-Second electrode; 410-Third electrode; 420-Fourth electrode. Detailed Implementation

[0055] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0056] Hereinafter, the terms "second," "first," etc., are used for descriptive convenience only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "second," "first," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0057] Furthermore, in the embodiments of this application, directional terms such as "upper," "lower," "left," and "right" may be defined relative to the orientation in which the components are schematically placed in the accompanying drawings. It should be understood that these directional terms can be relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation in which the components are placed in the accompanying drawings.

[0058] In this application, unless the context otherwise requires, the term "comprising" is interpreted as open-ended and encompassing, meaning "including, but not limited to," throughout the specification and claims. In the description, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "exemplary," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0059] In the embodiments of this application, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. Furthermore, the term "coupled connection" can be a direct electrical connection or an indirect electrical connection through an intermediate medium. The term "contact" can be direct contact or indirect contact through an intermediate medium.

[0060] In this embodiment of the application, "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following associated objects have an "or" relationship.

[0061] Exemplary embodiments are described in this application with reference to cross-sectional views and / or plan views, which are idealized exemplary drawings. In the drawings, the thickness of layers and regions is enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched regions shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the regions of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0062] To facilitate understanding of the technical solution, the structures involved in this application are explained below.

[0063] A vertical cavity surface emitting laser (VCSEL) is a novel type of semiconductor laser whose emitted light is perpendicular to the bottom surface. A typical VCSEL consists of three parts: an upper distributed Bragg reflector (DBR), a lower distributed Bragg reflector, and an active layer.

[0064] Distributed Bragg reflectors (DBRs) are composed of alternating layers of materials with different refractive indices grown along the light transmission direction. The thickness of each layer is one-quarter of the wavelength of the emitted light. By using several pairs of alternating layers of two or more semiconductor or dielectric materials, high reflectivity is achieved for a specific optical band. The greater the refractive index difference between the two materials, the higher the reflection efficiency. The principle of a DBR is that Fresnel reflection occurs at each interface of the materials with different refractive indices. When light of a specific wavelength is incident, the optical path difference between the reflected light at two adjacent interfaces is half a wavelength. Furthermore, the sign of the reflection coefficient at the interface also changes. Therefore, all reflected light at the interface undergoes destructive interference, resulting in strong reflection. The reflectivity is determined by the number of material layers and the refractive index difference between the materials. The reflection bandwidth is mainly determined by the refractive index difference.

[0065] This application provides a detection device that can be applied to fields such as optical communication, scanning imaging, and lidar.

[0066] The detection device includes a laser and a receiver. This application does not impose any special limitations on the specific form of the detection device. For ease of explanation, the following embodiments use a radar system as an example.

[0067] This application describes a radar system. Radar systems can be applied to communication equipment such as motor vehicles, autonomous vehicles, drones, railcars, bicycles, traffic lights, speed measuring devices, or network equipment (e.g., base stations and terminal devices in various systems) to achieve functions such as spatial scanning, obstacle avoidance, and route planning. This application applies to vehicle-to-vehicle radar systems, as well as radar systems between vehicles and drones or other devices, or radar systems between other devices. For example, radar systems can be installed on intelligent transportation equipment, smart home devices, robots, and other intelligent terminals. This application does not limit the type of terminal equipment used to install the radar system, the installation location of the radar system, or the function of the radar system.

[0068] For example, such as Figure 1 As shown, radar system 1 mainly includes signal transmitting module 2, signal receiving module 3, optical path adjustment module 4, and data processing module 5.

[0069] The signal transmitting module 2 is used to transmit laser signals to the object under test 6.

[0070] In some embodiments, the signal transmitting module 2 includes a laser array. For example, the laser array may be a vertical-cavity surface-emitting laser array.

[0071] VCSELs possess advantages such as low threshold current, no catastrophic optical damage (COD), small size, low power consumption, high efficiency, fast modulation rate, large modulation bandwidth, long lifetime, circular beam, small divergence angle, on-chip testing, easy two-dimensional array arrangement, and stable single-wavelength operation. Furthermore, their beam quality is far superior to that of edge-emitting lasers (EELs) and light-emitting diodes (LEDs). This makes VCSELs highly valuable for applications in data communication, sensing, lidar, materials processing, and three-dimensional sensing and imaging technologies.

[0072] The signal receiving module 3 is used to receive the laser signal reflected back from the object under test 6.

[0073] In some embodiments, the signal receiving module 3 includes a receiver array. For example, the receiver array may be an avalanche photodiode (APD) array.

[0074] The optical path adjustment module 4 is used to adjust the optical path of the laser. The optical path adjustment module 4 is located on the optical path where the laser signal is located. For example, Figure 1 As shown, the optical path of the laser signal includes the laser light path emitted by the signal transmitting module 2 (emitting light path 21) and the laser light path reflected back by the object under test 6 (reflection light path 31). That is, the optical path adjustment module 4 is located on both the emitting light path 21 and the reflection light path 31, enabling adjustment of both the angle of the emitted laser and the angle of the reflected laser. In this way, by setting the optical path adjustment module 4 to adjust the laser light path, the high collimation of the laser reaching the object under test 6 and entering the signal receiving module 3 can be improved, thereby enhancing the sensitivity and accuracy of the radar system 1.

[0075] The data processing module 5 is connected to the signal receiving module 3 and is used to analyze and process the laser signal reflected back from the object under test 6.

[0076] In some embodiments, the data processing module 5 includes a signal conversion submodule and a data processing submodule. The signal conversion submodule is connected to the signal receiving module 3 and is used to convert the laser signal reflected back from the object under test 6 into an electrical signal. The data processing submodule is connected to the signal conversion submodule and is used to process the electrical signal obtained by the signal conversion submodule to obtain data such as the distance, relative velocity, and spatial position relationship between the object under test 6 and the radar system 1.

[0077] In some embodiments, the data processing module 5 further includes an image generation submodule and an output module. The image generation submodule is connected to the data processing submodule and generates an image signal based on the processing result of the data processing submodule. The image signal can be a three-dimensional image or a two-dimensional image, etc. The output submodule is connected to the image generation submodule and is used to output the image signal generated by the image generation submodule to a terminal. The terminal can be various mobile display terminals such as mobile phones, tablets, and in-vehicle TVs.

[0078] The radar system 1 provided in this embodiment further includes a control module and a timing module. Both the control module and the timing module are connected to the signal transmission module 2. The timing module is used to generate timing pulse signals, and the control module controls the signal transmission module 2 to generate picosecond-level pulse laser signals according to the timing pulse signals, which are then irradiated onto the object under test 6.

[0079] An example is a vertical cavity surface-emitting laser, such as a single-mode (SM) vertical cavity surface-emitting laser. Due to its advantages such as small spectral width, small beam divergence angle, and near-Gaussian beam distribution, it is widely used in the signal transmission module 2 of the radar system 1 mentioned above.

[0080] Single-mode VCSELs are advantageous for increasing signal transmission distance and improving the coupling efficiency between the signal and the optical fiber, thereby enhancing the accuracy, sensitivity, speed, and efficiency of application systems. The following illustration uses a single-mode VCSEL laser as an example from an embodiment of this application.

[0081] Single-mode VCSELs can achieve error-free transmission over a distance of 2.2 km at a rate of 54 Gb / s. Currently, the modulation rate of single-mode VCSELs in on-off-key (OOK) modulation formats has exceeded 100 Gb / s, with an energy efficiency approaching 50 fJ / bit at 25°C and error-free transmission of 30 Gb / s at 115°C. In some advanced modulation formats, such as pulse amplitude modulation 4 (PAM4), carrierless amplitude and phase modulation (CAP), and discrete multi-tone (DMT), advanced signal processing and wavelength multiplexing technologies can further improve the transmission rate of VCSEL-based optical links, reaching speeds of up to 100 Gb / s, 200 Gb / s, and 400 Gb / s.

[0082] Among them, the near-infrared VCSEL adopts an oxide-confined structure. The transverse waveguide model of this VCSEL is similar to that of an optical fiber waveguide, which is a cylindrical waveguide structure.

[0083] Because the refractive index of the oxide confinement layer in oxide-confined VCSELs is very low, the refractive index (n) of the VCSEL core region is reduced. core The refractive index (n) is greater than that of the outer (clad) region of the VCSEL. clad ), that is, n core >n clad This causes total internal reflection at the interface between the core and outer layers of the fiber, limiting light transmission. Light transmission in multiple modes is confined to the core region. Reducing the core size allows other light modes to leak into the outer layer at certain angles. Therefore, only extremely small core sizes (e.g., less than or equal to 3 μm) can guarantee single-mode operation of the VCSEL.

[0084] In addition, since the preparation of the oxide confinement layer requires a chemical reaction between water vapor and the Al-containing layer, it is extremely dependent on the stability of the oxide environment and parameters such as the composition and thickness of the oxide layer. At present, it is not possible to mass-produce VCSELs in extremely small core areas, resulting in high costs for single-mode VCSELs.

[0085] In related technologies, proton injection technology, photonic crystal technology, or secondary epitaxy technology are typically used to achieve mass production of single-mode VCSELs.

[0086] Proton implantation technology uses protons to form an oxide confinement layer without changing its refractive index. Therefore, the refractive index of the core region is the same as that of the outer layer region, i.e., n... core =n clad This enables VCSEL to operate in single-mode.

[0087] However, proton injection technology breaks the chemical bonds of molecules, leading to a decrease in the binding force between molecules, resulting in lattice defects, which reduces the performance and reliability of VCSELs and makes them less practical.

[0088] Photonic crystal technology filters out all other modes at the light output port, leaving only one mode for output.

[0089] However, the photonic crystal process is complex and results in significant optical loss, which reduces the efficiency of VCSELs and leads to low performance.

[0090] Secondary epitaxy technology grows a high-refractive-index secondary epitaxial distributed Bragg mirror layer in the outer region outside the core region of the VCSEL, making the refractive index of the outer region higher than that of the core region.

[0091] However, the process of forming the secondary epitaxial distributed Bragg reflector layer is difficult and easily causes strain defects and interface defects, resulting in low performance of VCSEL.

[0092] Therefore, in order to solve the problems of low performance and high cost of VCSEL, this application provides a laser.

[0093] The following provides two specific embodiments to illustrate the laser.

[0094] Example 1

[0095] like Figure 2 As shown, the laser 100 mainly includes a first distributed Bragg reflector layer (hereinafter referred to as the first DBR layer) 110, a second distributed Bragg reflector layer (hereinafter referred to as the second DBR layer) 120, a third distributed Bragg reflector layer (hereinafter referred to as the third DBR layer) 130, a first current diffusion layer 210, a second current diffusion layer 220, an active layer 310, and electrodes. The electrodes provide current to the active layer 310 to generate photons. The third DBR layer 130 has a light-emitting port at its end furthest from the first DBR layer, from which the laser light is output.

[0096] like Figure 3 As shown in the figure, this application provides a method for fabricating a laser, including:

[0097] S1. A first DBR layer 110, a first current diffusion film, an active film, a second current diffusion film, and a second DBR film are sequentially stacked on a substrate.

[0098] The substrate material may include silicon (Si).

[0099] For example, such as Figures 4A-4E As shown, step S1 includes:

[0100] S11, such as Figure 4A As shown, a first DBR layer 110 is formed on the substrate.

[0101] A first DBR layer 110 is formed on the substrate, that is, as Figure 4A As shown, the first DBR layer 110 is disposed on the substrate. For example, the first DBR layer 110 is disposed on the surface of the substrate.

[0102] The first DBR layer 110 can be formed by, for example, chemical vapor deposition (CVD) or molecular beam epitaxy (MBE).

[0103] The first DBR layer 110 can be a multilayer semiconductor layer stacked together. The material of the first DBR layer 110 includes at least one of gallium arsenide (GaAs), gallium nitride (GaN), or indium phosphide (InP).

[0104] The first DBR layer 110 is a total reflection mirror with high reflectivity, for example, the reflectivity of the first DBR layer 110 is 99.9%.

[0105] For example, the first DBR layer 110 is an aluminum-doped (Al) DBR layer, that is, the first DBR layer 110 is composed of two different aluminum compositions with different refractive indices. x Ga 1-x As and Al y Ga 1-y Al is grown in alternating layers to achieve extremely high reflectivity, where x and y represent the Al composition (0 ≦ x, y ≦ 1). For example, the first DBR layer 110 is composed of Al... 0.22 Ga 0.78 As and Al 0.93 Ga 0.07 Al is formed by alternating growth. In this application embodiment, there is no limitation on the Al-doped composition of the first DBR layer 110 or the number of alternating layers; they can be reasonably set according to actual needs.

[0106] S12, such as Figure 4B As shown, a first current diffusion film 210' is formed on the first DBR layer 110.

[0107] Alternatively, it can be understood as forming a first current diffusion film 210' on the side of the first DBR layer 110 away from the substrate.

[0108] In other words, such as Figure 4B As shown, the first current diffusion film 210' is disposed on the side of the first DBR layer 110 away from the substrate. For example, the first current diffusion film 210' is disposed on the surface of the first DBR layer 110 away from the substrate.

[0109] The first current diffusion film 210' can be formed, for example, by chemical vapor deposition.

[0110] The material of the first current diffusion film 210' includes GaAs.

[0111] The first current diffusion film 210' facilitates current diffusion, provides better current diffusion effect, and improves current flow.

[0112] S13, such as Figure 4C As shown, an active film 310' is formed on the first current diffusion film 210'.

[0113] Alternatively, it can be understood as forming an active film 310' on the side of the first current diffusion film 210' away from the first DBR layer 110.

[0114] In other words, such as Figure 4C As shown, the active film 310' is disposed on the side of the first current diffusion film 210' away from the first DBR layer 110. For example, the active film 310' is disposed on the surface of the first current diffusion film 210' away from the first DBR layer 110.

[0115] The active membrane 310' can be formed, for example, by chemical vapor deposition.

[0116] Among them, the active film 310' is a multilayer semiconductor film stacked together.

[0117] For example, the material of the active membrane 310' includes GaAs. The active membrane 310' is an aluminum-doped (Al) DBR layer, that is, the active membrane 310' is made of Al with different aluminum compositions. x Ga 1-x As and Al y Ga 1-y Al is formed by alternating growth, where x and y represent the Al composition (0≦x, y≦1). This application does not limit the Al-doped composition or the number of alternating layers in the active film 310'; these can be set reasonably according to actual needs.

[0118] The material of the active membrane 310' can be the same as or different from the material of the first DBR layer 110, and this application does not limit this.

[0119] S14, such as Figure 4D As shown, a second current diffusion film 220' is formed on the active film 310'.

[0120] Alternatively, it can be understood that a second current diffusion film 220' is formed on the side of the active film 310' that is away from the first current diffusion film 210'.

[0121] In other words, such as Figure 4D As shown, the second current diffusion film 220' is disposed on the side of the active film 310' away from the first current diffusion film 210'. For example, the second current diffusion film 220' is disposed on the surface of the active film 310' away from the first current diffusion film 210'.

[0122] The method for forming the second current diffusion film 220' is, for example, to form the first current diffusion film 210' by chemical vapor deposition.

[0123] For example, the material of the second current diffusion film 220' can be the same as the material of the first current diffusion film 210'. For instance, the material of the second current diffusion film 220' includes GaAs.

[0124] The second current diffusion film 220' facilitates current diffusion, provides better current diffusion effect, and improves current flow.

[0125] S15, such as Figure 4E As shown, a second distributed Bragg reflector film (hereinafter referred to as the second DBR film) 120' is formed on the second current diffusion film 220'.

[0126] Alternatively, it can be understood as forming a second DBR film 120' on the side of the second current diffusion film 220' away from the active film 310'.

[0127] In other words, such as Figure 4E As shown, the second DBR film 120' is disposed on the side of the second current diffusion film 220' away from the active film 310'. For example, the second DBR film 120' is disposed on the surface of the second current diffusion film 220' away from the active film 310'.

[0128] The method for forming the second DBR film 120' is, for example, by chemical vapor deposition.

[0129] The second DBR film 120' is a multilayer semiconductor film stacked together, and the semiconductor film material includes at least one of gallium arsenide (GaAs), gallium nitride (GaN) or indium phosphide (InP).

[0130] For example, the second DBR film 120' is an aluminum-doped (Al) DBR layer, that is, the second DBR film 120' is composed of Al layers with different aluminum compositions. x Ga 1-x As and Al y Ga 1-y Al is formed by alternating growth, where x and y represent the Al composition (0≦x, y≦1). For example, the second DBR membrane 120' is composed of Al... 0.28 Ga 0.72 As and Al 0.96 Ga 0.04 Al is formed by alternating growth. In this application embodiment, there is no limitation on the Al-doped component of the second DBR film 120' or the number of alternating layers; they can be reasonably set according to actual needs.

[0131] The material of the second DBR membrane 120' can be the same as or different from the material of the first DBR layer 110; this application does not limit this.

[0132] S2. Etch the second DBR film 120' to form the second DBR layer 120.

[0133] In some embodiments, such as Figure 4F As shown, only the center of the second DBR film 120' is etched to form the second DBR layer 120.

[0134] In other embodiments, such as Figure 4G As shown, while etching the center of the second DBR film 120', a second DBR layer 120 is also formed on the edge portion of the second DBR film 120'.

[0135] At this point, the second DBR layer 120 and the second current diffusion film 220' form a stepped shape.

[0136] In other words, the edge of the second current diffusion film 220' expands relative to the edge of the second DBR layer 120. Or, the edge of the second DBR layer 120 contracts relative to the edge of the second current diffusion film 220'.

[0137] Along the thickness direction z of the second DBR layer 120, the projection of the second DBR layer 120 lies within the projection of the second current diffusion film 220'.

[0138] It should be clarified here that not every part of the second DBR layer 120 and the second current diffusion film 220' is stepped. That is, at least a portion of the edge of the second DBR layer 120 is located on the surface of the second current diffusion film 220'.

[0139] For ease of illustration, the following will all use... Figure 4G The second DBR layer 120 shown is explained below.

[0140] The second DBR layer 120 has a ring-shaped structure. For example, the second DBR layer 120 can be a circular ring or a square ring. This application embodiment does not limit this, as long as the second DBR layer 120 has a hollow structure.

[0141] It should be clarified here that the area surrounded by the second DBR layer 120 is the core region of the laser 100 to be formed. That is to say, step S2 etches the portion of the second DBR film 120' located in the core region and the portion corresponding to the light outlet.

[0142] S3. The second current diffusion film 220' and the active film 310' are etched, and the active film 310' is oxidized to form the second current diffusion layer 220 and the active layer 310.

[0143] For example, step S3 includes:

[0144] S31, such as Figure 4HAs shown, the second current diffusion film 220' and the active film 310' are etched to form the second current diffusion layer 220 and the active film layer 310.

[0145] It is clarified here that the etched second current diffusion film 220' serves as the second current diffusion layer 220 of the laser 100. The second current diffusion layer 220 is located between the active film layer 310” and the second DBR layer 120.

[0146] At this point, the second DBR layer 120 and the second current diffusion layer 220 form a stepped shape.

[0147] In other words, the edge of the second current diffusion layer 220 expands relative to the edge of the second DBR layer 120, or the edge of the second DBR layer 120 shrinks relative to the edge of the second current diffusion layer 220.

[0148] Along the thickness direction z of the second DBR layer 120, the projection of the second DBR layer 120 lies within the projection of the second current diffusion layer 220.

[0149] It should be clarified here that not every part of the second DBR layer 120 and the second current diffusion layer 220 is stepped. That is, at least a portion of the edge of the second DBR layer 120 is located on the surface of the second current diffusion layer 220.

[0150] In some embodiments, such as Figure 4H As shown, the edge of the active film layer 310” is flush with the edge of the second current diffusion layer 220. That is, in step S3, the second current diffusion layer 220’ and the active film 310’ are etched simultaneously to form the second current diffusion layer 220 and the active film layer 310”.

[0151] This simplifies the process and makes it easy to implement. For ease of illustration, the following will use... Figure 4H The active film layer 310 shown will be explained.

[0152] In other embodiments, such as Figure 4I As shown, the second current diffusion layer 220 and the active film layer 310” form a stepped shape.

[0153] In other words, the edge of the active film layer 310” expands relative to the edge of the second current diffusion layer 220. Or, the edge of the second current diffusion layer 220 shrinks relative to the edge of the active film layer 310”.

[0154] In other words, along the thickness direction z of the second DBR layer 120, the projection of the second current diffusion layer 220 is located within the projection of the active film layer 310".

[0155] It should be clarified here that not every part of the second current diffusion layer 220 and the active film layer 310” is stepped. That is, at least part of the edge of the second current diffusion layer 220 is located on the surface of the active film layer 310”.

[0156] In some embodiments, such as Figure 4I As shown, the first current diffusion film 210' serves as the first current diffusion layer 210 of the laser 100. The first current diffusion layer 210 is located between the active film layer 310" and the first DBR layer 110.

[0157] This simplifies the process and makes it easy to implement. For ease of illustration, the following will use... Figure 4I The first current diffusion layer 210 shown will be explained.

[0158] like Figure 4H As shown, the active film layer 310” and the first current diffusion layer 210 also form a stepped shape.

[0159] In other words, the edge of the first current diffusion layer 210 expands relative to the edge of the active film layer 310”, or the edge of the active film layer 310” shrinks relative to the edge of the first current diffusion layer 210.

[0160] Along the thickness direction z of the second DBR layer 120, the projection of the active film layer 310” is located within the projection of the first current diffusion layer 210.

[0161] It should be clarified here that not every part of the active film layer 310” and the first current diffusion layer 210 is stepped. That is, at least part of the edge of the active film layer 310” is located on the surface of the first current diffusion layer 210.

[0162] In other embodiments, such as Figure 4J As shown, step S31 further includes etching the first current diffusion film 210'.

[0163] It is clarified here that the etched first current diffusion film 210' serves as the first current diffusion layer 210 of the laser 100.

[0164] At this point, the first current diffusion layer 210 and the first DBR layer 110 form a stepped shape.

[0165] In other words, the edge of the first DBR layer 110 expands relative to the edge of the first current diffusion layer 210. Or, the edge of the first current diffusion layer 210 shrinks relative to the edge of the first DBR layer 110.

[0166] Along the thickness direction z of the second DBR layer 120, the projection of the first current diffusion layer 210 lies within the projection of the first DBR layer 110.

[0167] In this embodiment, the positional relationship between the edge of the first current diffusion layer 210 and the edge of the first DBR layer 110 is not limited; it can be set reasonably according to actual needs.

[0168] It should be noted that steps S2 and S31 can be etched simultaneously or in separate steps, and the comparison of the embodiments in this application is not limited.

[0169] S32, such as Figure 4K As shown, the active film layer 310” is oxidized to form the active layer 310.

[0170] In other words, the semiconductor film layer closest to the second current diffusion layer 220 of the active film layer 310 is locally oxidized to form an oxide confinement layer 311 and a current injection layer 312 of the active layer 310. The oxide confinement layer 311 is disposed around the current injection layer 312 and is located between the second DBR layer 120 and the first DBR layer 110.

[0171] Among them, the unoxidized portion of the semiconductor film closest to the second current diffusion layer 220 in the active film layer 310 is called the current injection layer 312.

[0172] The oxidation process for forming an oxide confinement layer is simple and easy to implement, avoiding lattice defects caused by proton implantation technology.

[0173] The active layer 310, also known as the light-emitting region, is used to generate photons under the influence of electric current.

[0174] The current injection layer 312 can be circular or rectangular, etc. The shape of the current injection layer 312 is not limited in this embodiment of the application, and can be reasonably set according to actual needs.

[0175] The material of the oxide confinement layer 311 may include aluminum oxide (Al). x O y ).

[0176] The function of the oxide confinement layer 311 is to confine the optical waveguide. The current is concentrated by the current injection layer 312 to increase the current density, thereby improving the uniformity of light emission of the laser 100.

[0177] S4, such as Figure 4L As shown, a third DBR layer 130 is formed in the region surrounded by the second DBR layer 120.

[0178] The second DBR layer 120 is arranged around the third DBR layer 130. That is, the second DBR layer 120 surrounds the third DBR layer 130.

[0179] At this time, the second DBR layer 120 is located in the outer region of the laser 100 to be formed, and the third DBR layer 130 is located in the core region of the laser 100 to be formed. The third DBR layer 130 is far away from the top surface of the first DBR layer 110.

[0180] In some embodiments, such as Figure 4L As shown, the top surface of the third DBR layer 130 away from the first DBR layer 110 is flush with the top surface of the second DBR layer 120 away from the first DBR layer 110.

[0181] In other embodiments, such as Figure 4M As shown, the top surface of the third DBR layer, which is furthest from the first DBR layer 110, is lower than the top surface of the second DBR layer, which is furthest from the first DBR layer 110. This embodiment does not limit this; it can be set reasonably according to actual needs.

[0182] The third DBR layer 130 can be formed, for example, by a lift-off process (e.g., thermal evaporation or electron beam evaporation), magnetron sputtering, physical-chemical vapor deposition, or molecular beam epitaxy. Lift-off processes are simple to operate and do not introduce optical losses or material defects.

[0183] The third DBR layer 130 is a multilayer dielectric layer stacked together. The dielectric layer material includes at least one of silicon oxide (SiO2), hafnium oxide (HfO2), or silicon nitride (Si3N4).

[0184] The third DBR layer 130 is a partial reflector, meaning it can both reflect and transmit light. For example, the reflectivity of the third DBR layer 130 is 99%. The side of the third DBR layer 130 furthest from the first DBR layer 110 serves as the light output port of the laser 100.

[0185] For example, the third DBR layer 130 is an aluminum-doped (Al) DBR layer. In this embodiment, the Al-doped composition of the third DBR layer 130 and the number of alternating layers are not limited, and can be reasonably set according to actual needs.

[0186] The material of the third DBR layer 130 is not limited in this application embodiment, as long as the refractive index of the third DBR layer 130 is less than that of the second DBR layer 120.

[0187] In this way, since the refractive index of the third DBR layer 130 is less than that of the second DBR layer 120, the refractive index of the core region is less than that of the outer region, and thus the laser 100 can be operated in single mode without limiting the size of the core region.

[0188] It should be noted that the alternating growth layers of the third DBR layer 130 and the second DBR layer 120 are staggered. This is because when the second DBR film 120' is etched to form the second DBR layer 120, part of the middle region of the second current diffusion layer 20 is etched away. Therefore, the third DBR layer 130 and the second DBR layer 120 are staggered.

[0189] It should be noted that when etching the second DBR film 120', the etching depth should not exceed the active film 310', in order to prevent current from being unable to flow into the active layer 310.

[0190] S5, such as Figure 4N As shown, a third electrode 410 and a fourth electrode 420 are formed.

[0191] For example, such as Figure 4O As shown, Figure 4O for Figure 4N The top view shows that both the third electrode 410 and the fourth electrode 420 are ring electrodes.

[0192] In this way, the current can be injected uniformly from all directions through the ring electrode, thereby improving the current injection effect and the uniformity of current injection on the surface of the active layer 310.

[0193] Alternatively, by way of example, in the embodiments of this application, the third electrode 410 or the fourth electrode 420 can be multiple ring-shaped electrode structures. For example... Figure 4P As shown, the third electrode 410 consists of two ring electrodes, and the fourth electrode 420 consists of one ring electrode.

[0194] In this way, multiple ring electrodes can be used to inject current into different regions of the active layer 310, reducing the lateral diffusion of current and ensuring good uniformity before current injection. The current density at the current injection point can be significantly reduced, thus improving the current injection uniformity of the device.

[0195] The third electrode 410 and the fourth electrode 420 can be circular ring electrodes. Alternatively, the third electrode 410 and the fourth electrode 420 can also be rectangular ring electrodes. This application does not limit the specific type of electrode.

[0196] Or, for example, such as Figure 4Q As shown, the third electrode 410 is a semi-ring electrode, and the fourth electrode 420 is a strip electrode.

[0197] The embodiments of this application do not limit the size and shape of the third electrode 410 and the fourth electrode 420; they can be reasonably set according to actual needs.

[0198] The material of the third electrode 410 may include titanium (Ti), platinum (Pt) or gold (Au), and the material of the fourth electrode 420 may include nickel (Ni), gold-germanium alloy (AuGe) or gold (Au).

[0199] The method for forming the third electrode 410 and the fourth electrode 420 is, for example, by forming the third electrode 410 and the fourth electrode 420 by a vapor deposition process.

[0200] The third electrode 410 is disposed on the first current diffusion layer 210, and the third electrode 410 is disposed around the active layer 310.

[0201] The fourth electrode 420 is disposed on the second current diffusion layer 220 and surrounds the second DBR layer 120.

[0202] In this way, the third electrode 410 and the fourth electrode 420 are used to inject current into the laser 100. The third electrode 410 and the fourth electrode 420 are located on the first current diffusion layer 210 and the second current diffusion layer 220 on the upper and lower sides of the active layer 310, respectively, which can reduce the injection current path.

[0203] The preparation method provided in this application does not impose any restrictions on the order of steps and can be reasonably adjusted as needed.

[0204] Furthermore, steps S1-S5 above can be omitted as needed, and are not required to be included in every step. Alternatively, steps can be added as needed, and are not limited to only the steps described above.

[0205] The method for fabricating a laser 100 provided in this application embodiment involves forming a first DBR layer 110, a first current diffusion film 210', an active film 310', a second current diffusion film 220', and a second DBR film 120' stacked sequentially. The second DBR film 120' is etched to form a ring-shaped structure, and a third DBR layer 130 is formed within the ring of the second DBR layer 120. The refractive index of the third DBR layer 130 is less than that of the second DBR layer 120. Simultaneously, the first current diffusion film 210', the active film 310', and the second current diffusion film 220' are also etched to form the first current diffusion layer 210, the active layer 310, and the second current diffusion layer 220, so that a third electrode 410 can be formed on the first current diffusion layer 210, and a fourth electrode 420 can be formed on the second current diffusion layer 220.

[0206] The method for fabricating a laser 100 provided in this application embodiment comprises a first DBR layer 110, a second DBR layer 120, a third DBR layer 130, and an active layer 310 forming the resonant cavity of the laser 100. The active layer 310 serves as the light-emitting region of the laser 100, the first DBR layer 110 serves as the total internal reflection mirror of the laser 100, and the second DBR layer 120 and the third DBR layer 130 serve as the light-emitting mirrors of the laser 100. Specifically, the second DBR layer 120 serves as the outer region of the laser 100, and the third DBR layer 130 serves as the core region of the laser 100.

[0207] After the third electrode 410 and the fourth electrode 420 are connected to the positive and negative terminals of the power supply, respectively, current is injected into the active layer 310 through the first current diffusion layer 210 and the second current diffusion layer 220, forming electrons and holes in the active layer 310. At this time, electrons and holes in the active layer 310 recombine to generate photons. Simultaneously, population inversion occurs in the active layer 310, that is, particles in the low-energy valence band are excited to the high-energy conduction band, so that the number of particles in the high-energy conduction band is greater than the number of particles in the low-energy valence band. When current is continuously injected, electrons in the high-energy conduction band transition to the low-energy valence band, forming stimulated emission and light amplification in the active layer 310. When stimulated emission occurs, photons are reflected back and forth between the first DBR layer 110 and the third DBR layer 130, and stimulated emission occurs with stimulated particles. The light amplification process is repeated continuously, which enhances the photons along the direction from the first DBR layer 110 to the third DBR layer 130, and finally forms a laser, which is output from the light outlet of the third DBR layer 130.

[0208] Because the refractive index of the second DBR layer 120 is greater than that of the third DBR layer 130, higher-order mode laser light will leak from the interface between the second DBR layer 120 and the third DBR layer 130 back to the second DBR layer 120, thus suppressing higher-order modes. This allows the fundamental mode laser light to exit from the exit port of the third DBR layer 130, achieving single-mode operation of the laser 100. Therefore, the laser 100 provided in this embodiment does not require limiting the aperture size of the current injection layer 312 to achieve single-mode operation.

[0209] Compared to existing technologies, the laser 100 fabrication method provided in this application has a second DBR layer 120 with a refractive index greater than that of the third DBR layer 130. Therefore, the refractive index of the outer region of the laser 100 is much greater than that of the core region, resulting in a stronger anti-waveguide effect and stronger suppression of higher-order modes, enabling single-mode operation of the laser 100. Thus, the laser 100 fabrication method in this application does not require limiting the aperture size of the current injection layer 312 to achieve single-mode operation, nor does it require limiting the size of the core region, enabling the fabrication of a laser 100 with a larger core region.

[0210] In addition, the embodiments of this application utilize a vapor deposition process to form the third DBR layer 130, which is simple and easy to implement, and avoids the impact of optical loss and material defects on the performance of the laser 100.

[0211] The following examples illustrate the laser provided in the embodiments of this application. The laser can be obtained using the laser fabrication method described above.

[0212] Based on this, such as Figure 5A and Figure 5B As shown, the laser 100 includes: a first DBR layer 110, a second DBR layer 120, a third DBR layer 130, a first current diffusion layer 210, a second current diffusion layer 220, an active layer 310, and electrodes. The electrodes include a third electrode 410 and a fourth electrode 420.

[0213] In this embodiment, the first DBR layer 110, the second DBR layer 120, the third DBR layer 130, and the active layer 310 constitute the resonant cavity of the laser 100. The active layer 310 serves as the light-emitting region of the laser 100, the second DBR layer 120 serves as the outer region of the laser 100, and the third DBR layer 130 serves as the core region of the laser 100, both used to emit laser light.

[0214] like Figure 5A and Figure 5B As shown, the second DBR layer 120 has a ring structure. This application embodiment does not limit the ring structure of the second DBR layer 120. The second DBR layer 120 is located in the outer region of the laser 100 to be formed.

[0215] For example, such as Figure 5A As shown, the second DBR layer 120 can be a circular ring.

[0216] Alternatively, for example, the second DBR layer 120 can be a rectangular ring. This application does not limit this aspect.

[0217] The third DBR layer 130 is located within the ring of the second DBR layer 120. That is, the second DBR layer 120 is arranged around the third DBR layer 130. The third DBR layer 130 is located in the core region of the laser 100 to be formed.

[0218] In some embodiments, the second DBR layer 120 is a multilayer semiconductor layer stacked together. The semiconductor layer material includes at least one of gallium arsenide (GaAs), gallium nitride (GaN), or indium phosphide (InP).

[0219] For example, the second DBR layer 120 is an aluminum-doped (Al) DBR layer, that is, the second DBR layer 120 is composed of two different aluminum compositions with different refractive indices. x Ga 1-x As and Al y Ga 1-y Al is formed by alternating growth, where x and y represent the Al composition (0≦x, y≦1). For example, the second DBR membrane 120' is composed of Al... 0.28 Ga 0.72 As and Al 0.96 Ga 0.04 As is formed by alternating growth.

[0220] This results in a higher refractive index for the second DBR layer 120.

[0221] In this embodiment, the Al-doped composition of the second DBR layer 120 and the number of alternating layers are not limited; they can be set reasonably according to actual needs.

[0222] In some embodiments, the third DBR layer 130 is a multilayer dielectric layer stacked together. The dielectric layer is made of at least one of silicon oxide (SiO2), hafnium oxide (HfO2), or silicon nitride (Si3N4).

[0223] The third DBR layer 130 is a partial reflector, meaning it can both reflect and transmit light. For example, the reflectivity of the third DBR layer 130 is 99%.

[0224] The side of the third DBR layer 130 furthest from the first DBR layer 110 serves as the light output port of the laser 100.

[0225] For example, the third DBR layer 130 is an aluminum-doped (Al) DBR layer. In this embodiment, the Al-doped composition of the third DBR layer 130 and the number of alternating layers are not limited, and can be reasonably set according to actual needs.

[0226] The effective refractive index of the dielectric DBR layer is approximately 1, while the effective refractive index of the semiconductor DBR layer (GaAs DBR layer) is greater than 3. Therefore, the effective refractive index of the outer layer region is greater than that of the core region, i.e., n clad >n core .

[0227] The embodiments of this application do not limit the materials of the dielectric layer and the semiconductor layer, as long as the equivalent refractive index of the multilayer dielectric layer is less than the equivalent refractive index of the multilayer semiconductor layer.

[0228] The materials of the second DBR layer 120 and the third DBR layer 130 in this embodiment are not limited, as long as the refractive index of the third DBR layer 130 is less than that of the second DBR layer 120.

[0229] The third DBR layer 130 serves as the core region of the laser 100, and the second DBR layer 120 serves as the outer region of the laser 100. The refractive index of the third DBR layer 130 is less than that of the second DBR layer 120, that is, as... Figure 5C As shown, the refractive index of the core region is lower than that of the outer layer region.

[0230] In this way, since the refractive index of the third DBR layer 130 is less than that of the second DBR layer 120, higher-order mode lasers will leak from the interface between the second DBR layer 120 and the third DBR layer 130 to the second DBR layer 120, thereby suppressing higher-order modes. This allows the fundamental mode laser to exit from the output port of the third DBR layer 130, achieving single-mode operation of the laser 100. Therefore, the laser 100 provided in this embodiment can achieve single-mode operation by having the refractive index of the second DBR layer 120 greater than that of the third DBR layer 130, without needing to limit the aperture size of the current injection layer 312. In other words, single-mode operation of the laser 100 can be achieved without limiting the size of the fiber core region.

[0231] For example, such as Figure 5B As shown, the top surface of the third DBR layer 130 away from the first DBR layer 110 is flush with the top surface of the second DBR layer 120 away from the first DBR layer 110.

[0232] Or, for example, such as Figure 5D As shown, the top surface of the third DBR layer, which is away from the first DBR layer 110, is lower than the top surface of the second DBR layer, which is away from the first DBR layer 110.

[0233] like Figure 5B As shown, the first DBR layer 110, the first current diffusion layer 210, the active layer 310, the second current diffusion layer 220, and the second DBR layer 120 are stacked sequentially.

[0234] That is, the first current diffusion layer 210 is disposed on the surface of the first DBR layer 110, the active layer 310 is disposed on the surface of the first current diffusion layer 210 away from the first DBR layer 110, the second current diffusion layer 220 is disposed on the surface of the active layer 310 away from the first current diffusion layer 210, and the second DBR layer 120 is disposed on the surface of the second current diffusion layer 220 away from the active layer 310.

[0235] The third DBR layer 130 is also disposed on the surface of the second current diffusion layer 220 away from the active layer 310.

[0236] like Figure 5B As shown, the first current diffusion layer 210 is located between the active layer 310 and the first DBR layer 110, and the second current diffusion layer 220 is located between the active layer 310 and the second DBR layer 120.

[0237] Regarding the structure of the second current diffusion layer 220, as follows: Figure 5B As shown, the second current diffusion layer 220 is located between the active layer 310 and the second DBR layer 120.

[0238] The material of the second current diffusion layer 220 includes GaAs.

[0239] In some embodiments, such as Figure 5B As shown, the second DBR layer 120 and the second current diffusion layer 220 form a stepped shape.

[0240] In other words, the edge of the second current diffusion layer 220 expands relative to the edge of the second DBR layer 120. Or, the edge of the second DBR layer 120 shrinks relative to the edge of the second current diffusion layer 220.

[0241] Along the thickness direction z of the laser 100, the projection of the second DBR layer 120 lies within the projection of the second current diffusion layer 220.

[0242] It should be clarified here that not every part of the second DBR layer 120 and the second current diffusion layer 220 is stepped. That is, at least a portion of the edge of the second DBR layer 120 is located on the surface of the second current diffusion layer 220.

[0243] This makes it easier to place the fourth electrode 420 on the second current diffusion layer 220.

[0244] The fourth electrode 420 is disposed on the second current diffusion layer 220, which is beneficial to the diffusion of current, can provide better current diffusion effect, and improve current flow.

[0245] It should be noted that the stepped portion formed by the second DBR layer 120 and the second current diffusion layer 220 is configured according to the structure of the fourth electrode 420.

[0246] Regarding the structure of the first current diffusion layer 210, as follows: Figure 5B As shown, the first current diffusion layer 210 is located between the active layer 310 and the first DBR layer 110.

[0247] The materials of the first current diffusion layer 210 and the second current diffusion layer 220 can be the same. For example, the material of the first current diffusion layer 210 includes GaAs.

[0248] In some embodiments, such as Figure 5B As shown, the active layer 310 and the first current diffusion layer 210 form a stepped shape.

[0249] In other words, the edge of the first current diffusion layer 210 expands relative to the edge of the active layer 310. Or, the edge of the active layer 310 shrinks relative to the edge of the first current diffusion layer 210.

[0250] Along the thickness direction z of the laser 100, the projection of the active layer 310 lies within the projection of the first current diffusion layer 210.

[0251] It should be clarified here that not every part of the active layer 310 and the first current diffusion layer 210 is stepped. That is, at least part of the edge of the active layer 310 is located on the surface of the first current diffusion layer 210.

[0252] This makes it easier to place the third electrode 410 on the first current diffusion layer 210.

[0253] It should be noted that the stepped portion formed by the active layer 310 and the first current diffusion layer 210 is configured according to the structure of the third electrode 410.

[0254] The third electrode 410 is disposed on the first current diffusion layer 210, which is beneficial to the diffusion of current, can provide better current diffusion effect, and improve current flow.

[0255] Regarding the structure of the third electrode 410 and the fourth electrode 420, as follows: Figure 5A and Figure 5B As shown, the third electrode 410 is disposed on the first current diffusion layer 210, and the fourth electrode 420 is disposed on the second current diffusion layer 220.

[0256] The material of the third electrode 410 may include titanium, platinum, or gold. The material of the fourth electrode 420 may include nickel, a gold-germanium alloy, or gold. This application does not limit the material in this regard.

[0257] In some embodiments, such as Figure 5A As shown, both the third electrode 410 and the fourth electrode 420 are ring-shaped structures.

[0258] In this way, the current can be injected uniformly from all directions through the ring electrode, thereby improving the current injection effect and the uniformity of current injection on the surface of the active layer 310.

[0259] For example, the third electrode 410 and the fourth electrode 420 are rectangular rings. Alternatively, the third electrode 410 and the fourth electrode 420 are circular rings. This application does not limit the specific embodiment to this.

[0260] The third electrode 410 is disposed around the active layer 310, and the fourth electrode 420 is disposed around the second DBR layer 120.

[0261] In the embodiments of this application, the third electrode 410 or the fourth electrode 420 can be multiple ring electrode structures.

[0262] For example, such as Figure 5E As shown, the third electrode 410 is an electrode with a ring structure, and the fourth electrode 420 is an electrode with multiple ring structures.

[0263] In this way, multiple ring electrodes can be used to inject current into different regions of the active layer 310, reducing the lateral diffusion of current and ensuring good uniformity before current injection. The current density at the current injection point can be significantly reduced, thus improving the current injection uniformity of the device.

[0264] In other embodiments, such as Figure 5F As shown, the third electrode 410 is a strip electrode, and the fourth electrode 420 is a semi-ring electrode.

[0265] The embodiments of this application do not limit the size and shape of the third electrode 410 and the fourth electrode 420; they can be reasonably set according to actual needs.

[0266] This clarifies that the structure of the third electrode 410 is configured to correspond to the degree to which the edge of the active layer 310 is recessed relative to the edge of the first current diffusion layer 210; or, it is configured to correspond to the degree to which the projected edge of the active layer 310 does not exceed the projected edge of the first current diffusion layer 210. The structure of the fourth electrode 420 is configured to correspond to the degree to which the edge of the second DBR layer 120 is recessed relative to the edge of the second current diffusion layer 220; or, it is configured to correspond to the degree to which the projected edge of the second DBR layer 120 does not exceed the projected edge of the second current diffusion layer 220.

[0267] The third electrode 410 and the fourth electrode 420 are used to inject current into the laser 100. In this embodiment, the third electrode 410 is disposed on the first current diffusion layer 410 and the fourth electrode 420 is disposed on the second current diffusion layer 420, which can reduce the injection current path.

[0268] Regarding the structure of active layer 310, as follows: Figure 5B As shown, the active layer 310 is located between the first current diffusion layer 210 and the second current diffusion layer 220.

[0269] The active layer 310 is a multilayer semiconductor layer stacked together. The material of the active layer 310 includes GaAs. The active layer 310 is an aluminum-doped DBR layer, meaning the active layer 310 is composed of Al with different aluminum compositions. x Ga 1-x As and Al y Ga 1-y Al is formed by alternating growth, where x and y represent the Al composition (0≦x, y≦1). This application does not limit the Al-doped composition of the active layer 310 or the number of alternating layers; they can be set reasonably according to actual needs.

[0270] The material of the active layer 310 can be the same as or different from the material of the first DBR layer 110; this application does not impose any restrictions on this.

[0271] like Figure 5B As shown, the laser 100 also includes an oxide confinement layer 311 and a current injection layer 312.

[0272] The oxide confinement layer 311 is located between the active layer 310 and the second current diffusion layer 220.

[0273] The oxide confinement layer 311 is disposed around the current injection layer 312, that is, the oxide confinement layer 311 surrounds the current injection layer 312. The current injection layer 312 can be circular or rectangular, etc. The shape of the current injection layer 312 is not limited in this embodiment of the application, and can be reasonably set according to actual needs.

[0274] The material of the oxide confinement layer 311 may include aluminum oxide (Al). x O y ).

[0275] The oxide confinement layer 311 is located below the second DBR layer 120, and the current injection layer 312 is located below the third DBR layer 130. Specifically, the oxide confinement layer 311 is located between the second DBR layer 120 and the active layer 310, and the current injection layer 312 is located between the third DBR layer 130 and the active layer 310.

[0276] The oxide confinement layer 311 is used to confine the optical waveguide, and the current is concentrated by the current injection layer 312 to increase the current density, thereby making the light emission uniformity of the laser 100 good.

[0277] In some embodiments, such as Figure 5B As shown, the edge of the active layer 310 is flush with the edge of the second current diffusion layer 220. That is, along the thickness direction z of the laser 100, the projection of the active layer 310 overlaps with the projection of the second current diffusion layer 220.

[0278] In other embodiments, such as Figure 6 As shown, the edge of the active layer 310 expands relative to the edge of the second current diffusion layer 220. Alternatively, the edge of the second current diffusion layer 220 contracts relative to the edge of the active layer 310.

[0279] In other words, along the thickness direction z of the laser 100, the projection of the second current diffusion layer 220 lies within the projection of the active layer 310.

[0280] Regarding the structure of the first DBR layer 110, as follows: Figure 6 As shown, in some implementations, the edge of the first DBR layer 110 is flush with the edge of the first current diffusion layer 210. That is, along the thickness direction z of the laser 100, the projection of the first DBR layer 110 overlaps with the projection of the first current diffusion layer 210.

[0281] In other embodiments, such as Figure 7 As shown, the edge of the first DBR layer 110 expands relative to the edge of the first current diffusion layer 210. Alternatively, the edge of the first current diffusion layer 210 shrinks relative to the edge of the first DBR layer 110.

[0282] In other words, along the thickness direction z of the laser 100, the projection of the first current diffusion layer 210 is located within the projection of the first DBR layer 110.

[0283] This application does not limit this aspect; it can be set reasonably according to actual needs.

[0284] The first DBR layer 110 is a multilayer semiconductor layer stacked together. The material of the first DBR layer 110 may include at least one of gallium arsenide, gallium nitride, or indium phosphide.

[0285] The first DBR layer 110 serves as the total reflection mirror of the laser 100 and has extremely high reflectivity; for example, the reflectivity of the first DBR layer 110 is 99.9%.

[0286] For example, the first DBR layer 110 is an aluminum-doped DBR layer, that is, the first DBR layer 110 is composed of two different aluminum compositions with different refractive indices. xGa 1-x As and Al y Ga 1-y Al is grown in alternating layers to achieve extremely high reflectivity, where x and y represent the Al composition (0 ≦ x, y ≦ 1). For example, the first DBR layer 110 is composed of Al... 0.22 Ga 0.78 As and Al 0.93 Ga 0.07 Al is formed by alternating growth. In this application embodiment, there is no limitation on the Al-doped composition of the first DBR layer 110 or the number of alternating layers; they can be reasonably set according to actual needs.

[0287] It should be noted that the material of the first DBR layer 110 and the material of the second DBR layer 120 may be the same or different, and this embodiment does not limit this.

[0288] In some embodiments, such as Figure 8 As shown, the laser 100 also includes a substrate, and all of the above structures are disposed on the substrate.

[0289] Based on the above description of the laser 100, the following, in conjunction with... Figure 9 The working method of the laser 100 described above will be explained.

[0290] like Figure 9 As shown in the embodiments of this application, a method for operating a laser is also provided, including:

[0291] S10, current is input to the active layer 310 through the third electrode 410 and the fourth electrode 420.

[0292] The laser 100 provided in this application embodiment comprises a first DBR layer 110, a second DBR layer 120, a third DBR layer 130, and an active layer 310 forming the resonant cavity of the laser 100. The active layer 310 serves as the light-emitting region of the laser 100, the second DBR layer 120 serves as the outer region of the laser 100, and the third DBR layer 130 serves as the core region of the laser 100.

[0293] Specifically, after the third electrode 410 and the fourth electrode 420 are connected to the positive and negative terminals of the power supply, the current is input to the first current diffusion layer 210 through the third electrode 410, input to the second current diffusion layer 220 through the fourth electrode 420, and then input to the active layer 310 through the first current diffusion layer 210 and the second current diffusion layer 220, where electrons and holes are formed.

[0294] Photons are generated in S20 and the active layer 130.

[0295] When an electric current is applied to the active layer 310, electrons and holes formed in the active layer 310 recombine to generate photons.

[0296] Simultaneously, population inversion occurs within the active layer 310, that is, particles in the low-energy valence band are excited to the high-energy conduction band, thus increasing the number of particles in the high-energy conduction band to more than the number in the low-energy valence band. When a current is continuously injected, electrons in the high-energy conduction band transition to the low-energy valence band, resulting in stimulated emission and light amplification within the active layer 310.

[0297] S30, the photon is reflected between the first DBR layer 110 and the third DBR layer 130, and the laser beam is output through the third DBR layer 130.

[0298] When stimulated emission occurs, photons are reflected back and forth between the first DBR layer 110 and the third DBR layer 130, and stimulated emission occurs with stimulated particles. The light amplification process is repeated continuously, which enhances the photons along the direction from the first DBR layer 110 to the third DBR layer 130, and finally forms a laser, which is output from the light outlet of the third DBR layer 130.

[0299] It should be noted that the first current diffusion layer 210 and the second current diffusion layer 220 do not affect the back-and-forth reflection of photons between the first DBR layer 110 and the third DBR layer 130.

[0300] The distribution region and transmission path of higher-order modes are mostly located near the interface between the core region and the outer layer region. When the refractive index of the third DBR layer 130 is less than that of the second DBR layer 120, the laser of the higher-order mode will leak from the interface between the second DBR layer 120 and the third DBR layer 130 to the second DBR layer 120, thus suppressing the higher-order mode. That is, when the refractive index of the core region is less than that of the outer layer region (n... core <n clad When, for higher-order modes, such as Figure 10A As shown, higher-order modes cannot gain gain because they are leaked into the outer region due to the anti-waveguide effect (fibers with a core region refractive index lower than the outer region are called anti-waveguides). Furthermore, the leakage capability is enhanced because higher-order modes have a greater divergence velocity.

[0301] like Figure 10B As shown, the fundamental mode distribution region is located at the center of the fiber core region and has a Gaussian distribution, so it is less affected by the waveguide. Therefore, the laser of the fundamental mode will be output from the output port of the laser 100, realizing the single-mode operation of the laser 100.

[0302] The laser 100 provided in this application embodiment includes a first DBR layer 110, a first current diffusion layer 210, an active layer 310, a second current diffusion layer 220, a second DBR layer 120 and a third DBR layer 130 disposed on the second current diffusion layer 220, a third electrode 410 disposed on the first current diffusion layer 210, and a fourth electrode 420 disposed on the second current diffusion layer 220, which are stacked sequentially. The second DBR layer 120 surrounds the third DBR layer 130, and the refractive index of the third DBR layer 130 is less than that of the second DBR layer 120.

[0303] The laser 100 provided in this embodiment comprises a first DBR layer 110, a second DBR layer 120, a third DBR layer 130, and an active layer 310 forming the resonant cavity of the laser 100. The active layer 310 serves as the light-emitting region of the laser 100, the first DBR layer 110 serves as the total internal reflection mirror of the laser 100, and the second DBR layer 120 and the third DBR layer 130 serve as the light-emitting mirrors of the laser 100. Specifically, the second DBR layer 120 serves as the outer region of the laser 100, and the third DBR layer 130 serves as the core region of the laser 100.

[0304] After the third electrode 410 and the fourth electrode 420 are connected to the positive and negative terminals of the power supply, respectively, current is injected into the active layer 310 through the first current diffusion layer 210 and the second current diffusion layer 220, forming electrons and holes in the active layer 310. At this time, electrons and holes in the active layer 310 recombine to generate photons. Simultaneously, population inversion occurs in the active layer 310, that is, particles in the low-energy valence band are excited to the high-energy conduction band, so that the number of particles in the high-energy conduction band is greater than the number of particles in the low-energy valence band. When current is continuously injected, electrons in the high-energy conduction band transition to the low-energy valence band, forming stimulated emission and light amplification in the active layer 310. When stimulated emission occurs, photons are reflected back and forth between the first DBR layer 110 and the third DBR layer 130, and stimulated emission occurs with stimulated particles. The light amplification process is repeated continuously, which enhances the photons along the direction from the first DBR layer 110 to the third DBR layer 130, and finally forms a laser, which is output from the light outlet of the third DBR layer 130.

[0305] Because the refractive index of the second DBR layer 120 is greater than that of the third DBR layer 130, higher-order mode laser light will leak from the interface between the second DBR layer 120 and the third DBR layer 130 back to the second DBR layer 120, thus suppressing higher-order modes. This allows the fundamental mode laser light to exit from the output port of the third DBR layer 130, achieving single-mode operation of the laser 100. Therefore, the laser 100 provided in this embodiment does not require limiting the aperture size of the current injection layer 312 to achieve single-mode operation.

[0306] Compared to existing technologies, the refractive index of the outer layer region of the laser 100 provided in this application embodiment is much greater than that of the fiber core region, resulting in a stronger anti-waveguide effect and stronger suppression of higher-order modes, enabling the laser 100 to operate in single mode. Therefore, the laser 100 provided in this application embodiment can achieve a laser 100 with a larger fiber core region without limiting the size of the fiber core region.

[0307] Example 2

[0308] The main difference between Example 2 and Example 1 lies in the electrode structure and position. This application also provides a method for fabricating a laser, such as... Figure 11 As shown, it includes:

[0309] S1', A first DBR layer 110, a first current diffusion film 210', an active film 310', a second current diffusion film 220', and a second DBR film 120' are formed on a substrate in sequence.

[0310] S2', Etch the second DBR film 120' to form the second DBR layer 120.

[0311] Steps S1' and S2' are the same as steps S1 and S2 above, and can be found in the descriptions of S1 and S2 above.

[0312] S3', such as Figure 12A As shown, the active membrane 310' is oxidized to form the active layer 310.

[0313] It is clarified here that the first current diffusion film 210' serves as the first current diffusion layer 210 of the laser 100, and the second current diffusion film 220' serves as the second current diffusion layer 220 of the laser 100.

[0314] Side oxidation is performed on the surface of the active film 310' near the second current diffusion layer 220 to form an oxidation confinement layer 311 and a current injection layer 312 of the active layer 310.

[0315] The current injection layer 312 can be circular or rectangular, etc. The shape of the current injection layer 312 is not limited in this embodiment of the application, and can be reasonably set according to actual needs.

[0316] The material of the oxide confinement layer 311 may include aluminum oxide (Al). x O y ).

[0317] The oxide confinement layer 311 is used to confine the optical waveguide, and the current is concentrated by the current injection layer 312 to increase the current density, thereby making the light emission uniformity of the laser 100 good.

[0318] S4', such as Figure 12B As shown, a third DBR layer 130 is formed in the region surrounded by the second DBR layer 120.

[0319] Step S4' is the same as step S4 above, and you can refer to the relevant description of S4 above.

[0320] S5', such as Figure 12C As shown, a first electrode 410' and a second electrode 420' are formed.

[0321] The material of the first electrode 410' may include titanium, platinum or gold, and the material of the second electrode 420' may include nickel, gold-germanium alloy or gold.

[0322] The first electrode 410' and the second electrode 420' can be formed, for example, by a vapor deposition process.

[0323] The first electrode 410' is formed on the side of the first DBR layer 110 away from the second DBR layer 120. Specifically, the first electrode 410' is formed on the side of the substrate away from the first DBR layer 110. That is, the first electrode 410' is formed on the surface of the substrate away from the first DBR layer 110.

[0324] The second electrode 420' is annular. The second electrode 420' is formed on the side of the second DBR layer 120 away from the first DBR layer 110. That is, the second electrode 420' is formed on the surface of the second DBR layer 120 away from the first DBR layer 110.

[0325] The first electrode 410' and the second electrode 420' are connected to the positive and negative terminals of the power supply, respectively, to provide current to the active layer 310.

[0326] This eliminates the need to etch the first current diffusion film 210' and the second current diffusion film 220', reducing the number of process steps.

[0327] It is clarified here that in some embodiments, it may be unnecessary to form the first current diffusion film 210' and the second current diffusion film 220'.

[0328] The preparation method provided in Embodiment 2 of this application does not impose any restrictions on the order of steps and can be reasonably adjusted as needed.

[0329] Furthermore, some steps in S1'-S5' above can be removed as needed, and it is not required that every step be included. Alternatively, some steps can be added as needed, and it is not limited to including only the steps mentioned above.

[0330] This application provides a laser that can be prepared using the laser preparation method provided in Embodiment 2.

[0331] The laser in Embodiment 2 differs from that in Embodiment 1 in the structure and position of the first electrode 410' and the second electrode 420'.

[0332] In some embodiments, such as Figure 13A and Figure 13B As shown, the first electrode 410' is disposed on the side of the first DBR layer 110 away from the second DBR layer 120. Specifically, the first electrode 410' is disposed on the side of the substrate away from the first DBR layer 110. That is, the first electrode 410' is disposed on the surface of the substrate away from the first DBR layer 110.

[0333] The second electrode 420' is annular. The second electrode 420' is disposed on the side of the second DBR layer 120 away from the first DBR layer 110. That is, the second electrode 420' is disposed on the surface of the second DBR layer 120 away from the first DBR layer 110.

[0334] In this way, the edges of the first current diffusion layer 210, the active layer 310, and the second current diffusion layer 220 can all be set flush, without the need to reserve positions for the first electrode 410' and the second electrode 420'.

[0335] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A laser, characterized in that, include: First distributed Bragg mirror layer; An active layer is disposed on the first distributed Bragg mirror layer; The second distributed Bragg reflector layer is disposed on the side of the active layer away from the first distributed Bragg reflector layer; A third distributed Bragg reflector layer is disposed on the active layer away from the first distributed Bragg reflector layer; a second distributed Bragg reflector layer is disposed around the third distributed Bragg reflector layer; the refractive index of the third distributed Bragg reflector layer is less than the refractive index of the second distributed Bragg reflector layer. An electrode is provided to supply current to the active layer so that the active layer generates photons, and a light-emitting port is provided at the end of the third distributed Bragg mirror layer away from the first distributed Bragg mirror layer.

2. The laser according to claim 1, characterized in that, The second distributed Bragg reflector layer is a multilayer semiconductor layer stacked together.

3. The laser according to claim 1 or 2, characterized in that, The third distributed Bragg reflector layer is a multilayer dielectric layer stacked together.

4. The laser according to claim 1 or 2, characterized in that, The electrode includes a first electrode and a second electrode; the first electrode is disposed on the side of the first distributed Bragg reflector layer away from the second distributed Bragg reflector layer; the second electrode is disposed on the side of the second distributed Bragg reflector layer away from the first distributed Bragg reflector layer.

5. The laser according to claim 1 or 2, characterized in that, The laser further includes a first current diffusion layer and a second current diffusion layer; the first current diffusion layer is located between the active layer and the first distributed Bragg mirror layer, and the second current diffusion layer is located between the active layer and the second distributed Bragg mirror layer. The electrode includes a third electrode and a fourth electrode; The third electrode is disposed on the first current diffusion layer and surrounds the active layer; The fourth electrode is disposed on the second current diffusion layer and surrounds the second distributed Bragg reflector layer.

6. The laser according to claim 2, characterized in that, The semiconductor layer is made of at least one of gallium arsenide, gallium nitride, or indium phosphide.

7. The laser according to claim 3, characterized in that, The material of the dielectric layer includes at least one of silicon oxide, hafnium oxide, or silicon nitride.

8. The laser according to claim 1 or 2, characterized in that, The laser further includes an oxide confinement layer and a current injection layer; the oxide confinement layer is disposed around the current injection layer; the oxide confinement layer is located between the second distributed Bragg mirror layer and the active layer, and the current injection layer is located between the third distributed Bragg mirror layer and the active layer.

9. The laser according to claim 1 or 2, characterized in that, The top surface of the third distributed Bragg reflector layer away from the first distributed Bragg reflector layer is flush with the top surface of the second distributed Bragg reflector layer away from the first distributed Bragg reflector layer; or, The top surface of the third distributed Bragg reflector layer, which is away from the top surface of the first distributed Bragg reflector layer, is lower than the top surface of the second distributed Bragg reflector layer, which is away from the top surface of the first distributed Bragg reflector layer.

10. A method for fabricating a laser, characterized in that, include: A first distributed Bragg reflector layer, an active film, and a second distributed Bragg reflector film are formed by sequentially stacking them. The second distributed Bragg mirror film is etched to form a second distributed Bragg mirror layer, which has a ring structure. A third distributed Bragg mirror layer is formed in the region surrounded by the second distributed Bragg mirror layer; the refractive index of the third distributed Bragg mirror layer is less than that of the second distributed Bragg mirror layer. An electrode is formed, which is used to provide current to the active membrane.

11. The method for fabricating a laser according to claim 10, characterized in that, The third distributed Bragg reflector layer is formed in the area surrounded by the second distributed Bragg reflector layer using a vapor deposition process.

12. The method for fabricating a laser according to claim 10 or 11, characterized in that, The electrode includes a first electrode and a second electrode; The first electrode is formed on the side of the first distributed Bragg reflector layer away from the second distributed Bragg reflector layer; the second electrode is formed on the side of the second distributed Bragg reflector layer away from the first distributed Bragg reflector layer.

13. The method for fabricating a laser according to claim 10 or 11, characterized in that, The active film is a multilayer semiconductor film stacked together; The semiconductor film closest to the second distributed Bragg mirror layer in the multilayer semiconductor film is locally oxidized to form an oxidation confinement layer and a current injection layer. The oxidation confinement layer is disposed around the current injection layer; the oxidation confinement layer is located between the second distributed Bragg mirror layer and the first distributed Bragg mirror layer, and the current injection layer is located between the third distributed Bragg mirror layer and the first distributed Bragg mirror layer.

14. The method for fabricating a laser according to claim 13, characterized in that, The preparation method further includes: Before forming the active film, a first current diffusion film is formed on the first distributed Bragg mirror layer; After the active film is formed, a second current diffusion film is formed on the side of the active film away from the first distributed Bragg mirror layer; Before performing localized oxidation on the semiconductor film, the preparation method further includes: The second current diffusion film and the active film are etched to form an active layer and a second current diffusion layer; the first current diffusion film serves as the first current diffusion layer of the laser.

15. The method for fabricating a laser according to claim 14, characterized in that, After forming the first current diffusion layer and the second current diffusion layer, the fabrication method further includes: A third electrode and a fourth electrode are formed; the third electrode is disposed on the first current diffusion layer and surrounds the active layer; the fourth electrode is disposed on the second current diffusion layer and surrounds the second distributed Bragg reflector layer.

16. A detection device, characterized in that, It includes the laser and receiver as described in any one of claims 1-9; the receiver is used to receive the light signal emitted by the laser.

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