Laser, optical assembly, optical module, and optical communication system

Abstract

A laser (100), an optical assembly, an optical module, and an optical communication system (1), relating to the technical field of semiconductor lasers, and used to improve the high-temperature reliability of lasers. The laser (100) comprises an N-type waveguide layer (201), an active layer (300), and a P-type waveguide layer (202) which are sequentially stacked. The active layer (300) comprises one or more quantum well layers (310) and a plurality of quantum barrier layers (320), and the quantum well layers (310) and the quantum barrier layers (320) are alternately stacked. The quantum barrier layer (320) closest to the P-type waveguide layer (202) has a band gap greater than those of the remaining quantum barrier layers (320) among the plurality of quantum barrier layers (320).

Description

Lasers, optical components, optical modules, and optical communication systems

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on July 28, 2023, with application number 202310944522.6 and application name “Laser, optical component, optical module and optical communication system”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of semiconductor laser technology, and in particular to a laser, an optical component, an optical module, and an optical communication system. Background Art

[0003] Semiconductor lasers have the characteristics of strong compatibility, low price and long life, and are widely used in laser communications, optical storage, optical gyroscopes, and lidar.

[0004] However, since semiconductor lasers are sensitive to temperature, as the temperature rises, the threshold current of the semiconductor laser increases, causing the optical power of the semiconductor laser to decrease.

[0005] Summary of the Invention

[0006] Embodiments of the present application provide a laser, an optical component, an optical module, and an optical communication system for improving the high-temperature reliability of the laser.

[0007] To achieve the above objectives, this application adopts the following technical solutions:

[0008] According to a first aspect of an embodiment of the present application, a laser is provided, comprising an N-type waveguide layer, an active layer, and a P-type waveguide layer stacked in sequence. The active layer comprises at least one quantum well layer and a plurality of quantum barrier layers, wherein the quantum well layers and the quantum barrier layers are arranged in an overlapping manner. The quantum barrier layer closest to the P-type waveguide layer has a band gap greater than the band gaps of the remaining quantum barrier layers in the plurality of quantum barrier layers.

[0009] In the laser provided in the embodiment of the present application, the band gap of the quantum barrier layer closest to the P-type waveguide layer in the active layer is the largest. Therefore, it is more difficult for electrons to be excited from the valence band to the conduction band in the quantum barrier layer closest to the P-type waveguide layer, and the concentration of intrinsic carriers is lower, which can suppress the leakage of carriers, thereby increasing the characteristic temperature of the laser, improving the high-temperature characteristics of the laser, and further improving the high-temperature reliability of the laser, thereby enhancing the performance of the laser.

[0010] In one possible implementation, the multiple quantum barrier layers include a first quantum barrier layer and a second quantum barrier layer. The first quantum barrier layer is located on the side of the second quantum barrier layer closest to the N-type waveguide layer, and the band gap of the second quantum barrier layer is no smaller than that of the first quantum barrier layer. This can further suppress carrier leakage, thereby improving the high-temperature performance and reliability of the laser.

[0011] In one possible implementation, the band gaps of multiple quantum barrier layers gradually increase from the N-type waveguide layer toward the P-type waveguide layer. This can further suppress carrier leakage, thereby improving the high-temperature performance and reliability of the laser.

[0012] In one possible implementation, along the direction from the N-type waveguide layer to the P-type waveguide layer, the band gaps of all quantum barrier layers, except for the one closest to the P-type waveguide layer, are equal. This facilitates the fabrication process and makes the laser easier to implement.

[0013] In one possible implementation, the sum of the stress of at least one quantum well layer and the stress of multiple quantum barrier layers is less than 200 ppm. This can offset the stress introduced by the band gap of the quantum barrier layer or quantum well layer, ensuring the performance of the laser.

[0014] In one possible implementation, the active layer includes multiple quantum well layers, with the band gap of the quantum well layer closest to the P-type waveguide layer being larger than the band gaps of the remaining quantum well layers. This can further suppress carrier leakage, thereby improving the high-temperature performance and reliability of the laser.

[0015] In one possible implementation, the band gaps of multiple quantum well layers gradually increase from the N-type waveguide layer toward the P-type waveguide layer. This can further suppress carrier leakage, thereby improving the high-temperature performance and reliability of the laser.

[0016] In one possible implementation, along the direction from the N-type waveguide layer to the P-type waveguide layer, the band gaps of all quantum well layers, except for the one closest to the P-type waveguide layer, are equal. This facilitates the fabrication process and makes the laser easy to implement.

[0017] In a possible implementation, the material of the quantum barrier layer includes Al x Ga y In 1-x-y P or Al x Ga 1-x As; wherein, the range of x is 0.3 to 0.7. In this way, the realization methods of the active layer can be increased.

[0018] In one possible implementation, the material of the quantum well layer includes Al x Ga y In 1-x-y P; wherein y ranges from 0.49 to 0.72. In this way, the realization methods of the active layer can be increased.

[0019] In one possible implementation, the laser further includes a first confinement layer and a second confinement layer; the first confinement layer is disposed on the side of the N-type waveguide layer away from the active layer, and the second confinement layer is disposed on the side of the P-type waveguide layer away from the active layer. In this way, the first and second confinement layers serve to confine the optical waveguide, concentrating current and increasing current density, thereby improving the laser's light uniformity.

[0020] According to a second aspect of the embodiments of the present application, an optical component is provided, comprising the laser according to any one of the first aspects and a laser driver, wherein the laser driver is used to drive the laser to emit light.

[0021] The optical component provided in the second aspect of the embodiment of the present 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.

[0022] According to a third aspect of the embodiments of the present application, an optical module is provided, comprising the optical component according to the second aspect and an optical receiving component, wherein the optical receiving component receives an optical signal transmitted by the optical component.

[0023] The optical module provided in the third aspect of the embodiment of the present application includes the optical component of the second aspect, and its beneficial effects are the same as those of the optical component, which will not be repeated here.

[0024] According to a fourth aspect of an embodiment of the present application, an optical communication system is provided, comprising the optical module and optical fiber according to the third aspect, wherein the optical module is connected to the optical fiber.

[0025] The optical communication system provided in the fourth aspect of the embodiment of the present application includes the optical module of the third aspect, and its beneficial effects are the same as those of the optical module, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is a schematic structural diagram of an optical communication system provided in an embodiment of the present application;

[0027] FIG2A is a schematic structural diagram of another optical communication system provided in an embodiment of the present application;

[0028] FIG2B is a schematic structural diagram of another optical communication system provided in an embodiment of the present application;

[0029] FIG3 is a schematic diagram of the structure of a laser provided in an embodiment of the present application;

[0030] FIG4 is a schematic diagram of a simulation of the energy band structure of a laser provided in an embodiment of the present application;

[0031] FIG5 is a schematic diagram of the structure of another laser provided in an embodiment of the present application;

[0032] FIG6A is a schematic diagram of the structure of another laser provided in an embodiment of the present application;

[0033] FIG6B is a schematic diagram of the structure of another laser provided in an embodiment of the present application;

[0034] FIG7 is a schematic diagram of a simulation of the energy band structure of another laser provided in an embodiment of the present application;

[0035] FIG8 is a schematic structural diagram of another laser provided in an embodiment of the present application;

[0036] FIG9 is a graph showing temperature and threshold current variation of a laser provided in an embodiment of the present application;

[0037] FIG10 is a graph showing carrier concentrations at different temperatures for a laser provided in an embodiment of the present application.

[0038] Figure 1: 1-optical communication system; 2-optical line terminal; 3-optical distribution network; 4-optical network unit; 21-optical transmitting module; 22-optical receiving module; 100-laser; 110-substrate; 210-first waveguide layer; 220-second waveguide layer; 201-N-type waveguide layer; 202-P-type waveguide layer; 300-active layer; 310-quantum well layer; 320-quantum barrier layer; 321-first quantum barrier layer; 322-second quantum barrier layer; 410-first confinement layer; 420-second confinement layer; 430-third confinement layer; 510-first bandgap transition layer; 520-second bandgap transition layer; 610-etching stop layer; 710-contact layer. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0040] 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 the technical features being referred to. Thus, a feature qualified as "second," "first," etc., may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0041] In addition, in the embodiments of the present application, directional terms such as "up", "down", "left", and "right" may be defined including but not limited to the orientation relative to the schematic placement of the components in the drawings. It should be understood that these directional terms may be relative concepts, which are used for relative descriptions and clarifications, and may change accordingly according to changes in the orientation of the components in the drawings.

[0042] In the embodiments of this application, unless otherwise specified or limited, the term "connection" should be understood in a broad sense. For example, "connection" can mean fixed connection, detachable connection, or integration; it can mean direct connection or indirect connection through an intermediate medium. In addition, the term "coupling" can mean direct electrical connection or indirect electrical connection through an intermediate medium. The term "contact" can mean direct contact or indirect contact through an intermediate medium.

[0043] In the embodiments of the present application, "and / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0044] The embodiment of the present application provides an optical communication system. As shown in FIG1 , the optical communication system 1 mainly includes at least two optical communication devices and optical fibers connecting the optical communication devices.

[0045] Optical communication systems have become the mainstream communication systems at present. For example, in optical communication systems, the access method of the access network (AN) is fiber access (FTTx), which is also called optical access network (OAN). The fiber access methods of the optical access network include fiber to the cabinet (FTTCab), fiber to the curb (FTTC), fiber to the building (FTTB) and fiber to the home (FTTH).

[0046] In some embodiments, the optical communication system 1 is integrated into an electronic device. The electronic device may include, for example, a server, a switch, a fiber optic network card, and a fiber optic transceiver. The optical communication system 1 may be integrated into the same electronic device or integrated into different electronic devices. This embodiment of the present application does not limit this, and may be configured appropriately based on actual circumstances.

[0047] Exemplarily, when a passive optical network (PON) is used as an optical communication system, the optical communication equipment may include, for example, any one of an optical line terminal (OLT), an optical network unit (ONU), or an optical network terminal (ONT).

[0048] The implementation of this application does not limit the specific types and structures of the optical communication system 1 and the optical communication equipment, and they can be reasonably configured according to actual conditions.

[0049] As shown in FIG1 , the PON includes an optical line terminal 2 , an optical distribution network (ODN) 3 , and an optical network unit 4 .

[0050] OLT2 is located in the central control station, and ODN3 is located on the user side. OND3 connects OLT2 and ONU4. The optical components in OLT2 and ONU4 convert and transmit network signals from optical to electrical sources.

[0051] In some embodiments, the PON further includes an optical network terminal (not shown in the figure). The ONT and the ONU 4 are arranged at different positions on the user side and implement similar functions.

[0052] ODN3 consists of optical splitters (SPLs) and optical fibers. The function of an optical splitter is to split one light path into two paths based on a certain splitting ratio, and then transmit the two light paths to different ONUs4 / ONTs. Generally, the more optical splitters cascaded in an ODN3, the more light can be split, and the more light paths can be generated.

[0053] For example, OLT2 is located at the central control station, and ODN3 is located on the user side. ODN3 connects OLT2 and ONU4. The optical modules in OLT2 and ONU4 convert network signals into optical and electrical signals and transmit them. ONT and ONU4 are located at different locations on the user side and perform similar functions.

[0054] The optical module may be integrated into the above-mentioned ONU4 or ONT, and the optical module may also be integrated into the above-mentioned OLT2.

[0055] For example, the optical module may include a small form-factor pluggable optical transceiver (SFP) optical module, an SFP+ optical module, or an XFP optical module, etc. This application does not limit this.

[0056] In some embodiments, the optical module includes a transmitting optical subassembly (TOSA) and a receiving optical subassembly (ROSA), wherein both the transmitting optical subassembly and the receiving optical subassembly are electrically connected to a printed circuit board.

[0057] For example, a bi-directional optical subassembly (BOSA) formed by integrating an optical transmitting assembly and an optical receiving assembly can be regarded as an optical assembly, or as the above-mentioned optical module.

[0058] The optical transmitting component may include, for example, a laser pointer, a laser cutting machine, or a laser pen, etc. The optical transmitting and receiving component may include, for example, a laser rangefinder or a laser radar, etc.

[0059] Exemplarily, the optical emission assembly includes an electro-optical conversion chip and a photodiode (e.g., a monitoring photodiode) (MD). The electro-optical conversion chip and the monitoring photodiode are packaged together to form the optical emission assembly. The monitoring photodiode is used to monitor the optical power output by the laser.

[0060] For example, the electro-optical conversion chip can be a chip composed of a laser diode (LD) or a semiconductor light-emitting diode. The electro-optical conversion chip receives an electrical signal carrying transmission information transmitted by the PCB, converts the electrical signal into an optical signal, and then outputs the optical signal through the optical device 10.

[0061] Exemplarily, the light receiving component includes a photoelectric conversion chip and an amplifier. The photoelectric conversion chip and the amplifier are packaged together to form the light receiving component. The photoelectric conversion chip can be, for example, a chip composed of a photodiode (PD), a chip composed of a PIN diode (PIN diode), or a chip composed of an avalanche photon diode (APD). The photoelectric conversion chip converts the received optical signal into an electrical signal, and then transmits the electrical signal to the amplifier, which amplifies the electrical signal and transmits the amplified electrical signal to the PCB.

[0062] In some embodiments, a visible light-based optical communication transceiver system is illustrated. As shown in FIG2A , the optical communication system 1 includes an optical transmitter module 21 , an optical receiver module 22 , and an optical fiber. The optical fiber is used to connect the optical transmitter module 21 and the optical receiver module 22 .

[0063] Exemplarily, as shown in FIG. 2A , the optical transmission module 21 includes a digital to analog converter (DAC), a laser driver (DRV), and a laser diode.

[0064] The laser driver is used to drive the laser diode to emit light. For example, the laser diode can also be a laser or other light-emitting device. This embodiment of the present application does not limit this.

[0065] Driven by the laser driver, the light emitted by the laser diode is transmitted to the light receiving module 22 .

[0066] Exemplarily, as shown in FIG. 2A , the optical receiving module 22 includes a photodiode, a transresistance amplifier (TIA), and an analog-to-digital converter (ADC).

[0067] The photodiode of the optical receiving module 22 receives the light transmitted from the optical transmitting module 21 and converts the optical signal into an electrical signal, which is then processed by a mutual impedance amplifier and an analog-to-digital converter.

[0068] In other embodiments, an optical communication transceiver system based on human-visible link connectivity is illustrated. As shown in FIG2B , the optical communication system 1 includes an optical transmitter module 21, an optical receiver module 22, an optical fiber, and an optical splitter. The optical fiber is used to connect the optical transmitter module 21 and the optical receiver module 22.

[0069] Exemplarily, as shown in FIG. 2B , the optical transmission module 21 includes a digital to analog converter (DAC), a laser driver (DRV), and a laser diode.

[0070] It is explained here that a laser diode is used as the light emitting device.

[0071] Exemplarily, as shown in FIG. 2B , the optical receiving module 22 includes a photodiode, a transresistance amplifier (TIA), and an analog-to-digital converter (ADC).

[0072] The optical transmitting module 21 or the optical receiving module 22 may be integrated into a printed circuit board, electrically connected to the printed circuit board, and then packaged.

[0073] It should be noted that the packaging form of the optical module or optical component described above is not limited in the embodiments of the present application. Taking the optical component as an example, the optical component can be a coaxial transistor outline (TO) package. Alternatively, a butterfly package can be used. For example, a box with a square housing can be used for packaging. Alternatively, the optical component can be a chip on board (COB) package.

[0074] In the embodiment of the present application, there is no limitation on the number of optical signals that the optical component can receive and receive, and whether the received and received optical signals share a common fiber. Reasonable settings can be made according to actual conditions.

[0075] Exemplarily, the optical component may be any one of a unidirectional optical component, a bidirectional optical component, a three-directional optical component, and a four-directional optical component.

[0076] Alternatively, illustratively, the optical component may also be a single-fiber or multi-fiber optical component.

[0077] For example, the optical component may include an electro-optical combo optical component.

[0078] Based on this, the present application also illustrates a laser, which can be applied to any of the above-mentioned optical communication systems, optical modules or optical components.

[0079] It is to be noted that the laser can be a bare laser die, or a packaged laser, or the aforementioned laser diode. This is not limited in the present embodiment.

[0080] As shown in FIG3 , the laser 100 primarily includes an N-type waveguide layer 201, an active layer 300, and a P-type waveguide layer 202, which are stacked in sequence. Specifically, the N-type waveguide layer 201, the active layer 300, and the P-type waveguide layer 202 are stacked in sequence along a first direction y, where the first direction y is the thickness direction of the N-type waveguide layer 201.

[0081] The active layer 300 includes a plurality of quantum well (QW) layers 310 and a plurality of quantum barrier (QB) layers 320 , and the quantum well layers 310 and the quantum barrier layers 320 are overlapped.

[0082] For ease of understanding, the characteristic temperature of the laser 100 is briefly introduced first. The characteristic temperature is used to describe the sensitivity of the threshold current of the laser 100 to temperature. In other words, the characteristic temperature can reflect the degree to which the threshold current of the laser 100 changes with temperature. The relationship between the threshold current of the laser 100 and the temperature is as shown in formula (1) and formula (2), where I this the threshold current, T is the operating temperature of the laser, T0 is a constant, and I0 is a constant, which represents the threshold current when the temperature T0 is. Formula (2) is the derivative of formula (1). In formula (2), I th / T0 can represent the threshold current I th The speed of change with temperature T. dI th / dT=I th / T0 (2)

[0083] When the laser 100 is in a high temperature environment (for example, a temperature greater than 70°C), its performance will be degraded, mainly manifested in an increase in the threshold current and a decrease in the slope efficiency, resulting in a decrease in the power of the laser 100 at the same operating current. In other words, as the temperature rises, the threshold current increases, causing the optical power to decrease. At this time, in order to maintain a constant optical power, the control circuit needs to increase the operating current, which will cause the temperature of the laser 100 to further increase, ultimately causing the laser 100 to fail.

[0084] Taking a red laser as an example, the material of the active layer 300 includes aluminum gallium indium phosphide (AlInGaP).

[0085] As shown in FIG4 , FIG4 schematically illustrates the band structure of the laser shown in FIG3 , the abscissa of FIG4 represents the position coordinate of the laser 100 shown in FIG3 in the first direction y, in μm, and the ordinate represents the energy band size at the corresponding position, in eV. As can be seen from FIG4 , the ability to confine electrons in the active layer 300 of the laser 100 is limited. The thermal conductivity of the aluminum gallium indium phosphide material is low (for example, the thermal conductivity is 6W·m -1 ·K -1 ~10W·m -1 ·K -1 ), and the quantum well layer 310 has a relatively shallow well depth. This can easily lead to severe electron leakage at high temperatures, causing laser power saturation and roll-off, resulting in poor performance of the red laser at high temperatures and making it difficult to optimize the epitaxial structure of the laser 100.

[0086] In addition, compared with a distributed feedback laser (DFB), the laser 100 does not have a filtering structure such as a grating, which limits the means of controlling T0.

[0087] Based on this, in order to improve the high-temperature reliability of the laser, an embodiment of the present application also provides a laser. As shown in Figure 5, the laser 100 mainly includes an N-type waveguide layer 201, an active layer 300, and a P-type waveguide layer 202, which are stacked in sequence. Among them, the active layer 300 includes at least one quantum well layer 310 and multiple quantum barrier layers 320. The quantum well layer 310 and the quantum barrier layer 320 are arranged in an overlapping manner. The band gap of the quantum barrier layer 320 closest to the P-type waveguide layer 202 is larger than the band gaps of the remaining quantum barrier layers in the multiple quantum barrier layers.

[0088] In this way, it is more difficult for electrons to be excited from the valence band to the conduction band in the quantum barrier layer 320 closest to the P-type waveguide layer 202 , and the concentration of intrinsic carriers is lower, thereby suppressing carrier leakage.

[0089] As shown in FIG. 6A , the laser 100 mainly includes a substrate 110 , a first waveguide layer 210 , an active layer 300 , and a second waveguide layer 220 , which are sequentially stacked on the substrate 110 .

[0090] That is, along the first direction y, the first waveguide layer 210 , the active layer 300 and the second waveguide layer 220 are stacked in sequence, wherein the first direction is the thickness direction of the substrate 110 .

[0091] The material of the substrate 110 may include, for example, gallium arsenide (GaAs). For example, the substrate 110 may be doped with silicon (Si).

[0092] For example, the material of the substrate 110 may include a semiconductor doped with an N-type material or a P-type material.

[0093] As shown in FIG. 6A , the first waveguide layer 210 is disposed on the substrate 110 .

[0094] For example, the material of the first waveguide layer 210 includes aluminum gallium indium phosphide (AlInGaP). 0.357 In 0.553 Ga 0.09 P.

[0095] The first waveguide layer 210 may be an N-type waveguide layer doped with an N-type material, or a P-type waveguide layer doped with a P-type material.

[0096] The doping of the first waveguide layer 210 may be, for example, unintentional doping (UID).

[0097] Exemplarily, the thickness of the first waveguide layer 210 is 50 nm to 250 nm. That is, along the first direction y, the size of the first waveguide layer 210 ranges from 50 nm to 250 nm. For example, the size can be 60 nm, 89 nm, 103 nm, 146 nm, 160 nm, 178 nm, 200 nm, or 234 nm.

[0098] 6A , the active layer 300 is disposed on a side of the first waveguide layer 210 away from the substrate 110 .

[0099] That is, the active layer 300 is disposed on a surface of the first waveguide layer 210 away from the substrate 110 .

[0100] The active layer 300 may also be referred to as a light-emitting region. The active layer 300 is used to generate photons under the action of current, constituting the light-emitting region of the laser 100 .

[0101] Illustratively, the laser 100 may further include at least two electrodes (not shown in FIG. 6A ).

[0102] After the electrodes are connected to the positive and negative poles of a power supply, current is input into the active layer 300 through the electrodes, forming electrons and holes in the active layer 300. At this point, the electrons and holes in the active layer 300 recombine to generate photons. Simultaneously, a population inversion occurs within the active layer 300, exciting particles in the low-energy valence band to the high-energy conduction band. This allows the number of particles in the high-energy conduction band to exceed that 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, causing stimulated emission of light within the active layer 300. When stimulated emission occurs, photons reflect back and forth within the active layer 300 and react with excited particles to generate stimulated emission. This light amplification process is repeated, amplifying the photons and ultimately forming a laser beam, which is output from the light output port.

[0103] The active layer 300 includes at least one quantum well layer 310 and a plurality of quantum barrier layers 320 , and the quantum well layer 310 and the quantum barrier layers 320 are arranged in an overlapping manner.

[0104] For example, the active layer 300 includes a quantum well layer 310, and the active layer 300 includes two quantum barrier layers 320. In this case, the quantum well layer 310 is located between the two quantum barrier layers 320.

[0105] Alternatively, illustratively, the active layer 300 includes a plurality of quantum well layers 310 and a plurality of quantum barrier layers 320 , and the quantum well layers 310 and the quantum barrier layers 320 are arranged in an overlapping manner.

[0106] The material of the quantum well layer 310 includes AlInGaP. The material of the quantum barrier layer 320 includes AlInGaP. The materials of the quantum well layer 310 and the quantum barrier layer 320 have different compositions.

[0107] For example, the materials of the multiple quantum well layers 310 may be the same or different in composition.

[0108] Exemplarily, the materials of the multiple quantum barrier layers 320 are different in composition.

[0109] It is explained here that the composition of the material of the quantum barrier layer 320 is related to the band gap of the quantum barrier layer 320 , the stress of the quantum barrier layer 320 , and the thickness of the quantum barrier layer 320 .

[0110] In the embodiment of the present application, there is no limitation on the number of quantum well layers 310 and the number of quantum barrier layers 320 in the active layer 300. The number of quantum well layers 310 in the active layer 300 is one less than the number of quantum barrier layers 320.

[0111] Exemplarily, the number of quantum barrier layers 320 in the active layer 300 ranges from 2 to 10, and the number of quantum well layers 310 in the active layer 310 ranges from 1 to 9. For example, as shown in FIG6A , the number of quantum barrier layers 320 in the active layer 300 is 3, and the number of quantum well layers 310 in the active layer 310 is 2. Alternatively, the number of quantum barrier layers 320 in the active layer 300 is 5, and the number of quantum well layers 310 in the active layer 310 is 4. Alternatively, the number of quantum barrier layers 320 in the active layer 300 is 10, and the number of quantum well layers 310 in the active layer 310 is 9.

[0112] For the sake of convenience, as shown in FIG6A , starting from the first waveguide layer 210 , the quantum well layers 310 of the active layer 300 are sequentially labeled as quantum well layers QW1 and quantum well layers QW2 , and the quantum barrier layers 320 of the active layer 300 are sequentially labeled as quantum barrier layers QB1 , quantum barrier layers QB2 , and quantum barrier layers QB3 .

[0113] That is, the quantum barrier layer QB1 , the quantum well layer QW1 , the quantum barrier layer QB2 , the quantum well layer QW2 , and the quantum barrier layer QB3 are sequentially stacked on the first waveguide layer 210 to constitute the active layer 300 of the laser 100 .

[0114] Each quantum barrier layer 320 and each quantum well layer 310 are described in sequence below.

[0115] The material of the quantum barrier layer QB1 includes Al 0.357 In 0.553 Ga 0.09The stress of the quantum barrier layer QB1 on the substrate 110 is zero. In other words, the quantum barrier layer QB1 does not exert either tensile stress or compressive stress on the substrate 110. The thickness of the quantum barrier layer QB1 is 5 nm to 20 nm. For example, the thickness of the quantum barrier layer QB1 can be 6 nm, 8 nm, 10 nm, 12 nm, 15 nm, or 19 nm.

[0116] The quantum barrier layer QB1 may be doped with an N-type material, or may be doped with a P-type material, which is not limited in the present embodiment.

[0117] It is noted that the type of material doped into the quantum barrier layer QB1 is the same as the type of material doped into the first waveguide layer 210 .

[0118] The doping of the quantum barrier layer QB1 is unintentional doping.

[0119] The material of the quantum well layer QW1 includes Al0In 0.68 Ga 0.32 The stress of quantum well layer QW1 on substrate 110 is 14101. In other words, quantum well layer QW1 exerts a certain tensile stress on substrate 110. Here, a positive stress value indicates tensile stress, while a negative stress value indicates compressive stress. The thickness of quantum well layer QW1 is 1 nm to 6 nm. For example, the thickness of quantum well layer QW1 can be 2 nm, 3 nm, 4 nm, or 6 nm.

[0120] The doping of the quantum well layer QW1 is unintentional doping.

[0121] In some embodiments, the quantum well layer QW1 and the first waveguide layer 210 are an integral structure.

[0122] The material of the quantum barrier layer QB2 includes Al 0.22 In 0.46 Ga 0.32 The stress of the quantum barrier layer QB2 on the substrate 110 is -9582. In other words, the quantum barrier layer QB2 exerts a certain compressive stress on the substrate 110. The thickness of the quantum barrier layer QB2 is 5 nm to 20 nm. For example, the thickness of the quantum barrier layer QB2 can be 6 nm, 8 nm, 10 nm, 12 nm, 15 nm, or 19 nm.

[0123] The doping of the quantum barrier layer QB2 is unintentional doping.

[0124] The material of the quantum well layer QW2 includes Al0In 0.68 Ga 0.32The stress of the quantum well layer QW2 on the substrate 110 is 14101. In other words, the quantum well layer QW2 exerts a certain tensile stress on the substrate 110. The thickness of the quantum well layer QW2 is 1 nm to 6 nm. For example, the thickness of the quantum well layer QW2 can be 2 nm, 3 nm, 4 nm, or 6 nm.

[0125] The doping of the quantum well layer QW2 is unintentional doping.

[0126] In some embodiments, the quantum well layer QW1 and the quantum well layer QW2 have the same material composition, thickness, and stress, that is, the band gap of the quantum well layer QW1 and the band gap of the quantum well layer QW2 are the same.

[0127] In other embodiments, the band gap of the quantum well layer QW1 and the band gap of the quantum well layer QW2 may also be different.

[0128] The band gaps of the quantum well layer QW1 and the quantum well layer QW2 are related to the types of materials doped with the first waveguide layer 210 and the second waveguide layer.

[0129] At this time, the material composition, thickness, and stress of the quantum well layer QW1 and the quantum well layer QW2 are changed according to actual conditions.

[0130] The material of the quantum barrier layer QB3 includes Al 0.45 In 0.46 Ga 0.09 The stress of the quantum barrier layer QB3 on the substrate 110 is -5983. In other words, the quantum barrier layer QB3 does not exert either tensile or compressive stress on the substrate 110. The thickness of the quantum barrier layer QB3 is 5 nm to 20 nm. For example, the thickness of the quantum barrier layer QB3 can be 6 nm, 8 nm, 10 nm, 11 nm, 12 nm, 15 nm, or 19 nm.

[0131] The quantum barrier layer QB3 may be doped with an N-type material, or may be doped with a P-type material, which is not limited in this embodiment of the present application.

[0132] It is explained here that the material type doped into the quantum barrier layer QB3 is different from the material type doped into the quantum barrier layer QB1 , that is, the material type doped into the quantum barrier layer QB3 is different from the material type doped into the first waveguide layer 210 .

[0133] The doping of the quantum barrier layer QB3 is unintentional doping.

[0134] 6A , the second waveguide layer 220 is disposed on a side of the active layer 300 away from the substrate 110 .

[0135] That is, the second waveguide layer 220 is disposed on the surface of the active layer 300 away from the substrate 110 .

[0136] For example, the material of the second waveguide layer 220 includes AlInGaP. 0.357 In 0.553 Ga 0.09 P.

[0137] The second waveguide layer 220 may be an N-type waveguide layer doped with an N-type material. Alternatively, the second waveguide layer 220 may be a P-type waveguide layer doped with a P-type material. This embodiment of the present application does not limit this.

[0138] It is noted that the type of material doped into the second waveguide layer 220 is different from the type of material doped into the first waveguide layer 210 .

[0139] That is, the type of material doped into the second waveguide layer 220 is the same as the type of material doped into the quantum barrier layer QB3 .

[0140] The doping of the second waveguide layer 220 may be, for example, unintentional doping.

[0141] Exemplarily, the thickness of the second waveguide layer 220 is 50 nm to 250 nm. That is, along the first direction y, the size of the second waveguide layer 220 ranges from 50 nm to 250 nm. For example, the size can be 60 nm, 89 nm, 103 nm, 136 nm, 150 nm, 160 nm, 178 nm, 200 nm, or 234 nm.

[0142] It is explained here that one of the first waveguide layer 210 and the second waveguide layer 220 is an N-type waveguide layer, and the other is a P-type waveguide layer.

[0143] In some embodiments, the first waveguide layer 210 is an N-type waveguide layer, and the second waveguide layer 220 is a P-type waveguide layer.

[0144] Correspondingly, the doping materials of the substrate 110 and the quantum barrier layer QB1 are both N-type materials, and the doping materials of the quantum barrier layer QB3 are both P-type materials.

[0145] The band gap of the quantum barrier layer 320 closest to the second waveguide layer 220 is larger than the band gaps of the remaining quantum barrier layers. In other words, the band gap of the quantum barrier layer 320 closest to the second waveguide layer 220 is the largest.

[0146] In some other embodiments, the first waveguide layer 210 is a P-type waveguide layer, and the second waveguide layer 220 is an N-type waveguide layer.

[0147] Correspondingly, the doped material type of the substrate 110 and the quantum barrier layer QB1 is P-type material, and the doped material type of the quantum barrier layer QB3 is N-type material.

[0148] The band gap of the quantum barrier layer 320 closest to the first waveguide layer 210 among the multiple quantum barrier layers 320 is larger than the band gaps of the remaining quantum barrier layers. In other words, the band gap of the quantum barrier layer 320 closest to the first waveguide layer 210 is the largest.

[0149] That is, the quantum barrier layer 320 closest to the P-type waveguide layer 202 has the largest band gap.

[0150] The embodiments of the present application do not limit this, and can be reasonably set according to actual conditions.

[0151] For the sake of convenience, the active layer 300 is schematically described below with the first waveguide layer 210 being an N-type waveguide layer and the second waveguide layer 220 being a P-type waveguide layer.

[0152] The band gap of the quantum barrier layer 320 closest to the second waveguide layer 220 is larger than the band gaps of the other quantum barrier layers 320 .

[0153] That is, the band gap of the quantum barrier layer 320 closest to the second waveguide layer 220 is the largest.

[0154] For example, as shown in FIG6B , the plurality of quantum barrier layers 320 include a first quantum barrier layer 321 and a second quantum barrier layer 322 , wherein the first quantum barrier layer 321 is located on a side of the second quantum barrier layer 322 close to the N-type waveguide layer 201 (first waveguide layer 210 ), and the band gap of the second quantum barrier layer 322 is not less than the band gap of the first quantum barrier layer 321 .

[0155] That is, the band gap of the first quantum barrier layer 321 is greater than or equal to the band gap of the second quantum barrier layer 322 .

[0156] In other words, the band gap of any quantum barrier layer 320 among the multiple quantum barrier layers 320 is not smaller than the band gap of any quantum barrier layer 302 between the quantum barrier layer 320 and the N-type waveguide layer 201 (first waveguide layer 210 ).

[0157] In some embodiments, the band gap of the quantum barrier layer 320 gradually increases along the direction from the first waveguide layer 210 to the second waveguide layer 220 .

[0158] That is, the band gap of the quantum barrier layer 320 gradually increases along the direction from the N-type waveguide layer 201 to the P-type waveguide layer 202 .

[0159] In this way, carrier leakage can be further suppressed, thereby improving the high-temperature performance of the laser 100 and enhancing the high-temperature reliability of the laser 100 .

[0160] For example, the active layer 300 in the laser 100 includes i quantum barrier layers 320. In the direction from the first waveguide layer 210 to the second waveguide layer 220, the quantum barrier layer QB1, the quantum barrier layer QB2, the quantum barrier layer QB3, ..., the quantum barrier layer QBi are arranged in sequence. QB1 <E QB2 <E QB3 <…… <E QBi .

[0161] Taking the laser 100 shown in FIG6A as an example, the band gap of the quantum barrier layer QB3 is larger than the band gap of the quantum barrier layer QB2, and the band gap of the quantum barrier layer QB2 is larger than the band gap of the quantum barrier layer QB1, that is, E QB1 <E QB2 <E QB3 .

[0162] In other embodiments, the band gap of any quantum barrier layer 320 among the multiple quantum barrier layers 320 except the quantum barrier layer 320 closest to the second waveguide layer 220 is not smaller than the band gap of the quantum barrier layer 320 on the side close to the first waveguide layer 210 .

[0163] That is, the band gap of any quantum barrier layer 320 other than the quantum barrier layer 320 closest to the second waveguide layer 220 is greater than or equal to the band gap of the quantum barrier layer 320 close to the first waveguide layer 210 .

[0164] That is, E QB1 ≤E QB2 ≤E QB3 ≤……≤E QB(i-1) .

[0165] Exemplarily, except for the quantum barrier layer 320 closest to the second waveguide layer 220 , the band gaps of the remaining quantum barrier layers 320 are all equal.

[0166] At this time, the band gaps of the remaining quantum barrier layers 320 are smaller than the band gap of the quantum barrier layer 320 closest to the second waveguide layer 220 .

[0167] That is, except for the quantum barrier layer 320 closest to the second waveguide layer 220 , the band gaps of the remaining quantum barrier layers 320 are equal and smaller than the band gap of the quantum barrier layer 320 closest to the second waveguide layer 220 .

[0168] That is, E QB1 =E QB2=E QB3 =……=E QB(i-1) <E QBi .

[0169] Alternatively, for example, along the direction from the first waveguide layer 210 to the second waveguide layer 220, the band gaps of the quantum barrier layers 320 may be initially equal and then increased. Alternatively, the band gaps may be increased first, with the band gaps of the middle portion of the quantum barrier layers 320 being equal and the band gap of the portion of the quantum barrier layers 320 near the second waveguide layer 220 increasing.

[0170] The embodiment of the present application does not limit this. It only needs to ensure that the band gap of the quantum barrier layer 320 does not decrease along the direction from the first waveguide layer 210 to the second waveguide layer 220 (the N-type waveguide layer 201 to the P-type waveguide layer).

[0171] That is, E QB1 ≤E QB2 ≤E QB3 ≤……≤E QB(i-1) <E QBi .

[0172] The material of the quantum barrier layer 320 includes either AlGaAs or AlGaInP.

[0173] For example, the material of the quantum barrier layer 320 includes Al x Ga y In 1-x-y P or Al x Ga 1-x As, in this case, the composition of Al is 0.3-0.7, that is, 0.3≤x≤0.7. For example, the material of the quantum barrier layer 320 may include Al 0.3 Ga 0.7 As、Al 0.4 Ga 0.6 As、Al 0.5 Ga 0.5 As、Al 0.6 Ga 0.4 As or Al 0.7 Ga 0.3 As.

[0174] Figure 7 illustrates the band structure of the laser shown in Figure 6A. The abscissa of Figure 7 represents the position coordinate of the laser 100 shown in Figure 6A in the first direction y, in μm, and the ordinate represents the band size at the corresponding position, in eV. As can be seen from Figure 7, the band structure forms an equivalent potential barrier at the position closest to the P-type waveguide layer 202, thereby blocking electrons and suppressing carrier leakage. This can improve the performance of the laser 100 in high-temperature environments and enhance the high-temperature reliability of the laser 100.

[0175] Regarding the quantum well layer 310 , in some embodiments, the band gaps of the plurality of quantum well layers 310 in the active layer 300 are equal.

[0176] For example, the active layer 300 in the laser 100 includes j quantum well layers 310. In the direction from the first waveguide layer 210 to the second waveguide layer 220, the quantum well layer QW1, the quantum well layer QW2, the quantum well layer QW3, ..., and the quantum well layer QWj are arranged in sequence. QW1 =E QW2 =E QW3 =……=E QWj .

[0177] Taking the laser 100 shown in FIG6A as an example, the band gap of the quantum well layer QW1 is equal to the band gap of the quantum well layer QW2. That is, E QW1 =E QW2 .

[0178] In other embodiments, the band gap of the quantum well layer 310 closest to the second waveguide layer 220 is larger than the band gaps of the remaining quantum well layers 310 .

[0179] That is, the band gap of the quantum well layer 310 closest to the second waveguide layer 220 is the largest.

[0180] Exemplarily, along the direction from the first waveguide layer 210 to the second waveguide layer 220 , the band gap of the quantum well layer 310 gradually increases.

[0181] That is, the band gap of the quantum well layer 310 gradually increases along the direction from the N-type waveguide layer to the P-type waveguide layer.

[0182] That is, E QW1 <E QW2 <E QW3 <…… <E QWj .

[0183] Taking the laser 100 shown in FIG6A as an example, the band gap of the quantum well layer QW2 is larger than the band gap of the quantum well layer QW1, that is, E QW1 <E QW2 .

[0184] Alternatively, illustratively, the band gap of any quantum well layer 310 among the multiple quantum well layers 310 except the quantum well layer 310 closest to the second waveguide layer 220 is not smaller than the band gap of the quantum well layer 310 close to the first waveguide layer 210 .

[0185] That is, the band gap of any quantum well layer 310 in the plurality of quantum well layers 310 except the quantum well layer 310 closest to the second waveguide layer 220 is greater than or equal to the band gap of the quantum well layer 310 close to the first waveguide layer 210 .

[0186] That is, E QW1 ≤E QW2 ≤E QW3 ≤……≤E QW(j-1) .

[0187] Exemplarily, except for the quantum well layer 310 closest to the second waveguide layer 220 , the band gaps of the remaining quantum well layers 310 are all equal.

[0188] At this time, the band gaps of the remaining quantum well layers 310 are smaller than the band gap of the quantum well layer 310 closest to the second waveguide layer 220 .

[0189] That is, except for the quantum well layer 310 closest to the second waveguide layer 220 , the band gaps of the remaining quantum well layers 310 are equal and smaller than the band gap of the quantum well layer 310 closest to the second waveguide layer 220 .

[0190] That is, E QW1 =E QW2 =E QW3 =……=E QW(j-1) <E QWj .

[0191] The embodiment of the present application does not limit this. It only needs to ensure that the band gap of the quantum well layer 310 does not decrease along the direction from the first waveguide layer 210 to the second waveguide layer 220 (the N-type waveguide layer 201 to the P-type waveguide layer).

[0192] That is, E QW1 ≤E QW2 ≤E QW3 ≤……≤E QW(j-1) <E QWj .

[0193] For example, the material of the quantum well layer 310 may include AlInGaP, wherein the In composition is greater than 0.49 and less than 0.72. In other words, the material of the quantum well layer 310 may include Al x Ga y In 1-x-y P, where y ranges from 0.49 to 0.72.

[0194] In the embodiment of the present application, there is no limitation on the composition of the material of the quantum well layer 310 and it can be reasonably set according to the actual situation. Therefore, in the embodiment of the present application, the material of the active layer 300 has a combination of multiple different components.

[0195] In some embodiments, the sum of stresses of the plurality of quantum well layers 310 and the plurality of quantum barrier layers 320 is less than 200 ppm.

[0196] Exemplarily, the active layer 300 in the laser 100 includes j quantum well layers 310 and i quantum barrier layers 320. In the direction from the first waveguide layer 210 to the second waveguide layer 220, the quantum barrier layer QB1, the quantum well layer QW1, the quantum barrier layer QB2, the quantum well layer QW2, the quantum barrier layer QB3, the quantum well layer QW3, ..., the quantum barrier layer QB(i-1), the quantum well layer QWj, and the quantum barrier layer QBi are arranged in sequence, where j = i-1.

[0197] The embodiment of the present application does not limit the number of quantum well layers 310 and quantum barrier layers 320 included in the active layer 300. It can be reasonably set according to actual conditions. It only needs to satisfy that the number of quantum barrier layers 320 in the active layer 300 is one more than the number of quantum well layers 310 in the active layer 310.

[0198] It is explained here that, in some embodiments, when the quantum barrier layer QB1 and the first waveguide layer 210 are an integrated structure, the number of quantum barrier layers 320 in the active layer 300 is equal to the number of quantum well layers 310 in the active layer 310 .

[0199] Due to the different band gaps of the quantum well layer 310 and the quantum barrier layer 320, stress exists in the quantum well layer 310 and the quantum barrier layer 320 relative to the substrate 110. For example, tensile stress or compressive stress exists. To alleviate the stress caused by the band gap and ensure the performance of the laser 100, the sum of the stress of all quantum well layers 310 and the stress of all quantum barrier layers 320 is illustratively less than 200 ppm.

[0200] That is to say, Right now, The stress can be obtained by the following formula (3), where C is the stress, ε is the strain of the corresponding quantum well layer 310 or quantum barrier layer 320, and d is the thickness of the layer. C = ε·d (3)

[0201] In some embodiments, with continued reference to FIG. 6A , the laser 100 further includes a first confinement layer 410 and a second confinement layer 420 .

[0202] The first confinement layer 410 and the second confinement layer 420 function to confine the optical waveguide, concentrate the current, increase the current density, and thereby improve the light emission uniformity of the laser 100 .

[0203] 6A , the first confinement layer 410 is disposed on a side of the first waveguide layer 210 away from the active layer 300 . In other words, the first confinement layer 410 is disposed on a side of the N-type waveguide layer 201 away from the active layer 300 .

[0204] In other words, the first confinement layer 410 is disposed between the first waveguide layer 210 and the substrate 110 .

[0205] For example, the material of the first confinement layer 410 may include Al 0.46 In 0.5 Ga 0.04 P.

[0206] The stress of the first confinement layer 410 is 0. That is, the first confinement layer 410 does not exert either tensile stress or compressive stress on the substrate 110 .

[0207] Exemplarily, the thickness of the first confinement layer 410 is 600 nm to 1500 nm. For example, the thickness of the first confinement layer 410 can be 650 nm, 850 nm, 1000 nm, 1160 nm, 1379 nm, or 1480 nm.

[0208] The first confinement layer 420 may be made of an N-type doped material, or a P-type doped material, which is not limited in this embodiment of the present application.

[0209] It is noted that the type of material doped into the first confinement layer 410 is the same as the type of material doped into the first waveguide layer 210 .

[0210] That is, the type of material doped into the first confinement layer 410 , the type of material doped into the quantum barrier layer QB1 , and the type of material doped into the first waveguide layer 210 are all the same.

[0211] For example, the doping concentration of the first confinement layer 410 is 5×10 18 cm -3 .

[0212] 6A , the second confinement layer 420 is disposed on a side of the second waveguide layer 220 away from the active layer 300 . In other words, the second confinement layer 420 is disposed on a side of the P-type waveguide layer 202 away from the active layer 300 .

[0213] For example, the material of the second confinement layer 420 may include Al 0.5 In 0.5 Ga0P.

[0214] The stress of the second confinement layer 420 is 0. That is, the second confinement layer 420 does not exert either tensile stress or compressive stress on the substrate 110 .

[0215] Exemplarily, the thickness of the second confinement layer 420 is 600 nm to 1200 nm. For example, the thickness of the second confinement layer 420 can be 650 nm, 850 nm, 1000 nm, 1160 nm, or 1180 nm.

[0216] The second confinement layer 420 may be made of an N-type doped material, or a P-type doped material, which is not limited in the present embodiment.

[0217] It is noted that the type of material doped into the second confinement layer 420 is the same as the type of material doped into the second waveguide layer 220 .

[0218] That is, the type of material doped into the second confinement layer 420 , the type of material doped into the quantum barrier layer QB3 , and the type of material doped into the second waveguide layer 220 are all the same.

[0219] For example, the doping concentration of the second confinement layer 420 is 2×10 18 cm -3 .

[0220] It is explained here that one of the first confinement layer 410 and the second confinement layer 420 is an N-type semiconductor layer, and the other is a P-type semiconductor layer.

[0221] Exemplarily, the first confinement layer 410 is an N-type semiconductor layer, and the second confinement layer 420 is a P-type semiconductor layer.

[0222] Correspondingly, the substrate 110 , the first confinement layer 410 , the first waveguide layer 210 and the quantum barrier layer QB1 are all doped with N-type materials, and the quantum barrier layer QB3 , the second confinement layer 420 and the second waveguide layer 220 are all doped with P-type materials.

[0223] Alternatively, illustratively, the first confinement layer 410 is a P-type semiconductor layer, and the second confinement layer 420 is an N-type semiconductor layer.

[0224] Correspondingly, the substrate 110 , the first confinement layer 410 , the first waveguide layer 210 and the quantum barrier layer QB1 are doped with P-type materials, and the quantum barrier layer QB3 , the second confinement layer 420 and the second waveguide layer 220 are doped with N-type materials.

[0225] In some embodiments, as shown in FIG. 8 , the laser 100 further includes a first bandgap transition layer 510 .

[0226] The first bandgap transition layer 510 is disposed between the substrate 110 and the first confinement layer 410 .

[0227] For example, the material of the first bandgap transition layer 510 may include Al 0.4Ga 0.6 As or Al 0.3 In 0.5 Ga 0.2 P.

[0228] Exemplarily, the thickness of the first bandgap transition layer 510 is 10 nm to 50 nm. For example, the thickness of the first bandgap transition layer 510 can be 15 nm, 20 nm, 30 nm, 44 nm, or 57 nm.

[0229] The first bandgap transition layer 510 may be doped with an N-type material, or may be doped with a P-type material, which is not limited in this embodiment of the present application.

[0230] It is noted that the type of material doped into the first bandgap transition layer 510 is the same as the type of material doped into the first waveguide layer 210 .

[0231] That is, the doping material of the first bandgap transition layer 510 , the doping material type of the first confinement layer 410 , the doping material type of the quantum barrier layer QB1 , and the doping material type of the first waveguide layer 210 are all the same.

[0232] For example, the doping concentration of the first bandgap transition layer 510 is 8×10 18 cm -3 .

[0233] In some embodiments, as shown in FIG. 8 , the laser 100 further includes a second bandgap transition layer 520 .

[0234] The second bandgap transition layer 520 is disposed on a side of the second confinement layer 420 away from the substrate 110 .

[0235] For example, the material of the second bandgap transition layer 520 may include Al 0.4 In 0.5 Ga 0.1 P or Al0In 0.5 Ga 0.5 P.

[0236] Exemplarily, the thickness of the second bandgap transition layer 520 is 10 nm to 50 nm. For example, the thickness of the second bandgap transition layer 520 can be 15 nm, 20 nm, 30 nm, 44 nm, or 57 nm.

[0237] The second bandgap transition layer 520 may be doped with an N-type material, or may be doped with a P-type material, which is not limited in the present embodiment.

[0238] It is noted that the type of material doped into the second bandgap transition layer 520 is the same as the type of material doped into the second waveguide layer 220 .

[0239] That is, the doping material of the second bandgap transition layer 520 , the doping material type of the second confinement layer 420 , the doping material type of the quantum barrier layer QB3 , and the doping material type of the second waveguide layer 220 are all the same.

[0240] For example, the doping concentration of the first bandgap transition layer 510 is 8×10 18 cm -3 .

[0241] It is explained here that one of the first bandgap transition layer 510 and the second bandgap transition layer 520 is an N-type semiconductor layer, and the other is a P-type semiconductor layer.

[0242] Exemplarily, the first bandgap transition layer 510 is an N-type semiconductor layer, and the second bandgap transition layer 520 is a P-type semiconductor layer.

[0243] Correspondingly, the substrate 110, the first confinement layer 410, the first waveguide layer 210, the first confinement layer 410 and the quantum barrier layer QB1 are all doped with N-type materials, and the quantum barrier layer QB3, the second confinement layer 420 and the second waveguide layer 220 are all doped with P-type materials.

[0244] Alternatively, illustratively, the first bandgap transition layer 510 is a P-type semiconductor layer, and the second bandgap transition layer 520 is an N-type semiconductor layer.

[0245] Correspondingly, the substrate 110, the first confinement layer 410, the first waveguide layer 210, the first confinement layer 410 and the quantum barrier layer QB1 are all doped with P-type materials, and the quantum barrier layer QB3, the second confinement layer 420 and the second waveguide layer 220 are all doped with N-type materials.

[0246] Continuing with reference to FIG. 8 , in some embodiments, the laser 100 further includes a third confinement layer 430 .

[0247] The third confinement layer 430 is disposed on a side of the second waveguide layer 220 away from the active layer 300 . In other words, the second confinement layer 420 is disposed on a side of the P-type waveguide layer 202 away from the active layer 300 .

[0248] As shown in FIG. 8 , the third confinement layer 430 is disposed on a side of the second confinement layer 420 close to the substrate 110 .

[0249] For example, the material of the third confinement layer 430 may include Al 0.5 In 0.5 Ga0P.

[0250] The stress of the third confinement layer 430 is 0. That is, the third confinement layer 430 does not exert either tensile stress or compressive stress on the substrate 110 .

[0251] Exemplarily, the thickness of the third confinement layer 430 is 0 nm to 200 nm. For example, the thickness of the third confinement layer 430 may be 40 nm, 65 nm, 85 nm, 100 nm, 160 nm, or 190 nm.

[0252] The third confinement layer 430 may be made of an N-type doped material, or a P-type doped material, which is not limited in this embodiment of the present application.

[0253] It is noted that the type of material doped into the third confinement layer 430 is the same as the type of material doped into the second confinement layer 420 .

[0254] That is, the material type doped into the third confinement layer 430 , the material type doped into the second confinement layer 420 , the material type doped into the quantum barrier layer QB3 , and the material type doped into the second waveguide layer 220 are all the same.

[0255] For example, the doping concentration of the third confinement layer 430 is 2×10 18 cm -3 .

[0256] Exemplarily, as shown in FIG. 8 , the laser 100 further includes an etch stop layer (ESL) 610 .

[0257] The etch stop layer 610 is disposed on a side of the third confinement layer 430 away from the substrate 110 .

[0258] As shown in FIG. 8 , the etch stop layer 610 is disposed between the second confinement layer 420 and the third confinement layer 430 .

[0259] For example, the material of the etch stop layer 610 may include Al0In 0.5 Ga 0.5 P.

[0260] The stress of the etch stop layer 610 is 0. That is, the etch stop layer 610 does not exert either tensile stress or compressive stress on the substrate 110 .

[0261] Exemplarily, the thickness of the etch stop layer 610 is 10 nm to 50 nm. For example, the thickness of the etch stop layer 610 can be 14 nm, 20 nm, 27 nm, 36 nm, 40 nm, or 49 nm.

[0262] The etch stop layer 610 may be made of an N-type doped material, or a P-type doped material, which is not limited in this embodiment of the present application.

[0263] It is noted that the material type doped into the etch stop layer 610 is the same as the material type doped into the third confinement layer 430 and the material type doped into the second confinement layer 420 .

[0264] That is, the material type doped into the etch stop layer 610 , the material type doped into the third confinement layer 430 , the material type doped into the second confinement layer 420 , the material type doped into the quantum barrier layer QB3 , and the material type doped into the second waveguide layer 220 are all the same.

[0265] For example, the doping concentration of the etch stop layer 610 is 2×10 18 cm -3 .

[0266] Exemplarily, as shown in FIG. 8 , the laser 100 further includes a contact layer 710 .

[0267] The contact layer 710 is disposed on a side of the third confinement layer 430 away from the substrate 110 .

[0268] As shown in FIG. 8 , the contact layer 710 is disposed on a side of the second bandgap transition layer 520 away from the substrate 110 .

[0269] For example, the material of the contact layer 710 may include GaAs.

[0270] Exemplarily, the thickness of the contact layer 710 is 50 nm to 250 nm. For example, the thickness of the contact layer 710 can be 64 nm, 86 nm, 127 nm, 178 nm, 200 nm, or 235 nm.

[0271] The contact layer 710 may be made of an N-type doped material, or a P-type doped material, which is not limited in this embodiment of the present application.

[0272] It is noted that the type of material doped into the contact layer 710 is the same as the type of material doped into the second waveguide layer 220 .

[0273] That is, the material type doped into the contact layer 710, the material type doped into the etch stop layer 610, the material type doped into the third confinement layer 430, the material type doped into the second confinement layer 420, the material type doped into the quantum barrier layer QB3, and the material type doped into the second waveguide layer 220 are all the same.

[0274] For example, the doping concentration of the etch stop layer 610 is 8×10 18 cm -3 .

[0275] This concludes the introduction to the laser 100 provided in the embodiment of the present application.

[0276] In some embodiments, the substrate 110, the first bandgap transition layer 510, the first confinement layer 410, the first waveguide layer 210, and the quantum barrier layer QB1 are all doped with N-type materials, and the quantum barrier layer QBi, the second waveguide layer 220, the third confinement layer 430, the etch stop layer 610, the second confinement layer 420, the second bandgap transition layer 520, and the contact layer 710 are all doped with P-type materials.

[0277] At this time, along the direction from the first waveguide layer 210 to the second waveguide layer 220 , the band gaps of the multiple quantum barrier layers 320 in the active layer 300 increase, and the band gap of the quantum barrier layer 320 (quantum barrier layer QBi) closest to the second waveguide layer 220 is the largest.

[0278] In other embodiments, the substrate 110, the first bandgap transition layer 510, the first confinement layer 410, the first waveguide layer 210, and the quantum barrier layer QB1 are all doped with P-type materials, and the quantum barrier layer QBi, the second waveguide layer 220, the third confinement layer 430, the etch stop layer 610, the second confinement layer 420, the second bandgap transition layer 520, and the contact layer 710 are all doped with N-type materials.

[0279] At this time, along the direction from the second waveguide layer 220 to the first waveguide layer 210 , the band gaps of the multiple quantum barrier layers 320 in the active layer 300 increase, and the band gap of the quantum barrier layer 320 (quantum barrier layer QB1 ) closest to the first waveguide layer 210 is the largest.

[0280] The laser 100 provided in an embodiment of the present application includes an N-type waveguide layer 201, an active layer 300, and a P-type waveguide layer 202, which are stacked in sequence. The active layer 300 includes multiple quantum well layers 310 and multiple quantum barrier layers 320, which are arranged in an overlapping manner. The quantum well layers 310 and the quantum barrier layers 320 are arranged so as to overlap. The band gap of the quantum barrier layer 320 closest to the P-type waveguide layer 201 is larger than the band gaps of the remaining quantum barrier layers 320. In the laser 100 provided in the embodiment of the present application, the band gap of the quantum barrier layer 320 closest to the P-type waveguide layer 201 in the active layer 300 is the largest. Therefore, it is more difficult for electrons to be excited from the valence band to the conduction band in the quantum barrier layer 320 closest to the P-type waveguide layer 202, and the concentration of intrinsic carriers is lower, which can suppress the leakage of carriers, thereby increasing the characteristic temperature of the laser 100, improving the high-temperature characteristics of the laser 100, and further improving the high-temperature reliability of the laser 100, thereby enhancing the performance of the laser 100.

[0281] Taking the first waveguide layer 210 of the laser 100 doped with an N-type material and the second waveguide layer 220 doped with a P-type material as an example, simulations are performed on different lasers, and the simulation results are described below.

[0282] Figure 9 shows that the threshold current (I th ) changes. The horizontal axis of Figure 9 represents the temperature T of the laser, in K, and the vertical axis represents the threshold current (I th ) takes the value of the natural logarithm e. Use In(I th ) and T to reflect that as the temperature T increases, the threshold current I th The curve shown in Figure 9 is the threshold current I th Curve of change with temperature T. As can be seen from FIG9 , as the temperature increases, the threshold current I th Always higher than the threshold current I of the laser shown in Figure 3 th .

[0283] Through simulation, it can be concluded that the characteristic temperature T0 of the laser 100 provided in the embodiment of the present application is 190.49 K. The characteristic temperature T0 of the laser shown in Figure 3 is 113.92 K. Therefore, it can be seen that the characteristic temperature T0 of the laser provided in the embodiment of the present application is at least 67% higher than the characteristic temperature T0 of the laser shown in Figure 3.

[0284] Figure 10 shows the carrier concentrations at different positions of two lasers at room temperature (T is 300K) and high temperature (T is 364K). The horizontal axis of Figure 10 represents the position coordinate of the laser 100 in the first direction y, in μm, and the vertical axis represents the carrier concentration at the corresponding position, in cm -3 .

[0285] As can be seen from FIG10 , at high temperatures, the carrier concentration of the laser 100 provided in the embodiment of the present application is higher than the carrier concentration of the laser illustrated in FIG3 . At room temperature, the carrier concentration of the laser 100 provided in the embodiment of the present application is higher than the carrier concentration of the laser illustrated in FIG3 . In other words, by comparison, the carrier concentration of the laser 100 provided in the embodiment of the present application is high.

[0286] It can be seen that at room temperature (300K), the laser 100 provided by the embodiment of the present application has the highest carrier concentration and the lowest electron leakage. At high temperature (364K), the laser 100 provided by the embodiment of the present application has the highest electron concentration and the lowest electron leakage.

[0287] The above is only a specific embodiment of the present application, but the scope of protection of this application is not limited to this. Any changes or substitutions within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A laser, characterized in that: include: N-type waveguide layer; An active layer, disposed on the N-type waveguide layer; A P-type waveguide layer, arranged on a side of the active layer away from the N-type waveguide layer; The active layer includes at least one quantum well layer and multiple quantum barrier layers, and the quantum well layer and the quantum barrier layer are overlapped; the band gap of the quantum barrier layer closest to the P-type waveguide layer is larger than the band gaps of the remaining quantum barrier layers in the multiple quantum barrier layers.

2. The laser according to claim 1, characterized in that The multiple quantum barrier layers include a first quantum barrier layer and a second quantum barrier layer, the first quantum barrier layer is located on a side of the second quantum barrier layer close to the N-type waveguide layer, and the band gap of the second quantum barrier layer is not less than the band gap of the first quantum barrier layer.

3. The laser according to claim 1 or 2, characterized in that: Along the direction from the N-type waveguide layer to the P-type waveguide layer, the band gaps of the plurality of quantum barrier layers gradually increase.

4. The laser according to claim 1 or 2, characterized in that: Along the direction from the N-type waveguide layer to the P-type waveguide layer, except for the quantum barrier layer closest to the P-type waveguide layer, the band gaps of the remaining quantum barrier layers among the multiple quantum barrier layers are equal.

5. The laser according to any one of claims 1 to 4, characterized in that: A sum of stress of the at least one quantum well layer and stress of the plurality of quantum barrier layers is less than 200 ppm.

6. The laser according to any one of claims 1 to 5, characterized in that: The active layer includes a plurality of quantum well layers, and the band gap of the quantum well layer closest to the P-type waveguide layer is greater than the band gaps of the remaining quantum well layers in the plurality of quantum well layers.

7. The laser according to any one of claims 1 to 6, characterized in that: The material of the quantum barrier layer includes Al x Ga y In 1- x-y P or Al x Ga 1-x As; wherein, the range of x is 0.3 to 0.

7.

8. The laser according to any one of claims 1 to 7, characterized in that: The material of the quantum well layer includes Al x Ga y In 1- x-y P; wherein y ranges from 0.49 to 0.

72.

9. The laser according to any one of claims 1 to 8, characterized in that: The laser further includes a first confinement layer and a second confinement layer; the first confinement layer is disposed on a side of the N-type waveguide layer away from the active layer, and the second confinement layer is disposed on a side of the P-type waveguide layer away from the active layer.

10. An optical component, characterized in that: It comprises the laser according to any one of claims 1 to 9 and a laser driver, wherein the laser driver is used to drive the laser to emit light.

11. An optical module, characterized in that: It comprises the optical component as claimed in claim 10 and a light receiving component, wherein the light receiving component receives the optical signal transmitted by the optical component.

12. An optical communication system, characterized in that: It comprises at least two optical communication devices and an optical fiber; the optical communication devices are connected via the optical fiber; the optical communication device comprises the optical module as claimed in claim 11.

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