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

Abstract

The embodiment of the invention provides a laser, an optical assembly, an optical module and an optical communication system, relates to the technical field of semiconductor lasers, and is used for improving the high-temperature reliability of the laser. The laser comprises an N-type waveguide layer, an active layer and a P-type waveguide layer which are sequentially stacked. Wherein the active layer comprises at least one quantum well layer and a plurality of quantum barrier layers, and the quantum well layer and the quantum barrier layers are arranged in an overlapping manner. 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.

Description

Technical Field

[0001] 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

[0002] Semiconductor lasers have the characteristics of strong compatibility, low price and long life. They are widely used in laser communications, optical storage, optical gyroscopes, and lidar.

[0003] 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. Summary of the invention

[0004] 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.

[0005] In order to achieve the above purpose, this application adopts the following technical solutions:

[0006] In 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, and the quantum well layer and the quantum barrier layer are arranged in an overlapping manner. The band gap of the quantum barrier layer closest to the P-type waveguide layer is greater than the band gap of the remaining quantum barrier layers in the plurality of quantum barrier layers.

[0007] 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.

[0008] In a 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 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. In this way, carrier leakage can be further suppressed, thereby improving the high temperature performance of the laser and improving the high temperature reliability of the laser.

[0009] In a possible implementation, the band gaps of multiple quantum barrier layers gradually increase along the direction from the N-type waveguide layer to the P-type waveguide layer. In this way, carrier leakage can be further suppressed, thereby improving the high-temperature performance of the laser and enhancing the high-temperature reliability of the laser.

[0010] In a possible implementation, along the direction from the N-type waveguide layer to the P-type waveguide layer, the band gaps of the remaining quantum barrier layers are all equal except for the quantum barrier layer closest to the P-type waveguide layer. In this way, the preparation process of the laser is convenient and easy to implement.

[0011] In a 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. In this way, the stress introduced by the band gap of the quantum barrier layer or the quantum well layer can be offset to ensure the performance of the laser.

[0012] In a possible implementation, the active layer includes multiple quantum well layers, and the band gap of the quantum well layer closest to the P-type waveguide layer is larger than the band gap of the remaining quantum well layers in the multiple quantum well layers. In this way, carrier leakage can be further suppressed, thereby improving the high-temperature performance of the laser and improving the high-temperature reliability of the laser.

[0013] In a possible implementation, the band gaps of multiple quantum well layers gradually increase along the direction from the N-type waveguide layer to the P-type waveguide layer. In this way, carrier leakage can be further suppressed, thereby improving the high-temperature performance of the laser and enhancing the high-temperature reliability of the laser.

[0014] In a possible implementation, along the direction from the N-type waveguide layer to the P-type waveguide layer, the band gaps of the quantum well layers except the quantum well layer closest to the P-type waveguide layer are all equal. In this way, the preparation process of the laser is convenient and easy to implement.

[0015] 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.

[0016] In a possible implementation, the material of the quantum well layer includes Al x Ga y In 1-x-y P; wherein the range of y is 0.49 to 0.72. In this way, the realization methods of the active layer can be increased.

[0017] In a possible implementation, the laser further includes a first limiting layer and a second limiting layer; the first limiting layer is arranged on the side of the N-type waveguide layer away from the active layer, and the second limiting layer is arranged on the side of the P-type waveguide layer away from the active layer. In this way, the first limiting layer and the second limiting layer are used to limit the optical waveguide, concentrate the current, increase the current density, and thus improve the light emission uniformity of the laser.

[0018] According to a second aspect of an embodiment 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.

[0019] 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.

[0020] According to a third aspect of an embodiment 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.

[0021] 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.

[0022] According to a fourth aspect of an embodiment of the present application, an optical communication system is provided, comprising the optical module and the optical fiber according to the third aspect, wherein the optical module is connected to the optical fiber.

[0023] 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 the beneficial effects of the optical module, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of an optical communication system provided in an embodiment of the present application;

[0025] Figure 2A A schematic diagram of the structure of another optical communication system provided in an embodiment of the present application;

[0026] Figure 2B A schematic diagram of the structure of another optical communication system provided in an embodiment of the present application;

[0027] Figure 3 A schematic diagram of the structure of a laser provided in an embodiment of the present application;

[0028] Figure 4 A schematic diagram of a simulation of the energy band structure of a laser provided in an embodiment of the present application;

[0029] Figure 5 A schematic diagram of the structure of another laser provided in an embodiment of the present application;

[0030] Fig. 6A A schematic diagram of the structure of another laser provided in an embodiment of the present application;

[0031] Figure 6B A schematic diagram of the structure of another laser provided in an embodiment of the present application;

[0032] Figure 7 A schematic diagram of a simulation of the energy band structure of another laser provided in an embodiment of the present application;

[0033] Figure 8 A schematic diagram of the structure of another laser provided in an embodiment of the present application;

[0034] Fig. 9 A temperature and threshold current variation curve diagram of a laser provided in an embodiment of the present application;

[0035] Fig.10 This is a carrier concentration curve diagram of a laser at different temperatures provided in an embodiment of the present application.

[0036] Reference numerals

[0037] 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

[0038] 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 of the embodiments.

[0039] In the following, the terms "second", "first", etc. are used only for convenience of description and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "second", "first", etc. may explicitly or implicitly include one or more of the feature. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0040] 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 description and clarification, and may change accordingly according to changes in the orientation of the components in the drawings.

[0041] In the embodiments of the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. In addition, the term "coupled" can be a direct electrical connection or an indirect electrical connection through an intermediate medium. The term "contact" can be a direct contact or an indirect contact through an intermediate medium.

[0042] In the embodiments of the present application, "and / or" describes the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B may be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0043] The present application embodiment provides an optical communication system. Figure 1 As shown, the optical communication system 1 mainly includes at least two optical communication devices and optical fibers connecting the optical communication devices.

[0044] Optical communication systems have become the mainstream communication systems at present. For example, in optical communication systems, the access mode of access network (AN) is fiber access (FTTx), which is also called optical access network (OAN). The fiber access modes of 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).

[0045] 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, an optical network card, and an optical transceiver. The optical communication system 1 may be integrated into the same electronic device or may be separately integrated into different electronic devices. This embodiment of the application does not limit this, and may be reasonably set according to actual conditions.

[0046] 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).

[0047] 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 set according to actual conditions.

[0048] The optical communication system is a passive optical fiber network. Figure 1 As shown, the PON includes an optical line terminal 2, an optical distribution network (ODN) 3 and an optical network unit 4.

[0049] Among them, OLT2 is set in the central control station, and ODN3 is set at the user side. OND3 is used to connect OLT2 and ONU4. The optical devices in OLT2 and ONU4 are used to perform photoelectric conversion and transmission of network signals.

[0050] 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.

[0051] Among them, ODN3 is composed of an optical splitter (SPL) and optical fibers. The function of the optical splitter is to split one path of light into two paths according to a certain splitting ratio, so as to transmit the two paths of light to different ONU4 / ONTs respectively. Generally, the more cascaded optical splitters in ODN3, the more times of splitting, and the more paths of light that can be split.

[0052] Exemplarily, OLT2 is set at the central control station, and ODN3 is set at the user side. ODN3 is used to connect OLT2 and ONU4. The optical modules in OLT2 and ONU4 are used to perform photoelectric conversion and transmission of network signals. ONT and ONU4 are set at different locations on the user side and implement similar functions.

[0053] 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.

[0054] Exemplarily, the optical module may include a small form-factor pluggable transceiver optical module (SFP) optical module, an SFP+ optical module, or an XFP optical module, etc. This application does not limit this.

[0055] 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 the printed circuit board.

[0056] Exemplarily, a bi-directional optical subassembly (BOSA) formed by integrating an optical transmitting component and an optical receiving component can be regarded as an optical component, and can also be regarded as the above-mentioned optical module.

[0057] The optical transmitting component may include, for example, a laser pointer, a laser cutting machine, or a laser pen, etc. The optical transceiver component may include, for example, a laser rangefinder or a laser radar, etc.

[0058] Exemplarily, the optical emission component includes an electro-optical conversion chip and a photodiode (eg, a monitoring photodiode) (MD). The electro-optical conversion chip and the monitoring photodiode are packaged together to form the optical emission component. The monitoring photodiode is used to monitor the optical power output by the laser.

[0059] Exemplarily, the electro-optical conversion chip may be a chip composed of a laser diode (LD) or a chip composed of 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.

[0060] 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 a light receiving component. The photoelectric conversion chip can be, for example, a chip composed of a photodiode (photo diode, PD), a chip composed of a PIN diode (pin diode), or a chip composed of an avalanche photon diode (avalanche photon diode, APD). Among them, the photoelectric conversion chip converts the received optical signal into an electrical signal, and then transmits the electrical signal to the amplifier, the amplifier amplifies the electrical signal, and transmits the amplified electrical signal to the PCB.

[0061] In some embodiments, a visible light based optical communication transceiver system is illustrated. Figure 2A As shown, the optical communication system 1 includes an optical transmitting module 21 , an optical receiving module 22 and an optical fiber. The optical fiber is used to connect the optical transmitting module 21 and the optical receiving module 22 .

[0062] For example, Figure 2AAs shown, the optical transmission module 21 includes a digital to analog converter (DAC), a laser driver (DRV) and a laser diode.

[0063] The laser driver is used to drive the laser diode to emit light. For example, the laser diode may also be a laser or other light-emitting device. This embodiment of the present application does not limit this.

[0064] Driven by the laser driver, the light emitted by the laser diode is transmitted to the light receiving module 22 .

[0065] For example, Figure 2A As shown, the optical receiving module 22 includes a photodiode, a transresistance amplifier (TIA), and an analog converter to digital (ADC).

[0066] 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.

[0067] In other embodiments, an optical communication transceiver system based on link connectivity visible to human eyes is illustrated. Figure 2B As shown, the optical communication system 1 includes an optical transmitting module 21 , an optical receiving module 22 , an optical fiber and an optical splitter. The optical fiber is used to connect the optical transmitting module 21 and the optical receiving module 22 .

[0068] For example, Figure 2B As shown, the optical transmission module 21 includes a digital to analog converter (DAC), a laser driver (DRV) and a laser diode.

[0069] It is explained here that a laser diode is used as the light emitting device.

[0070] For example, Figure 2B As shown, the optical receiving module 22 includes a photodiode, a transresistance amplifier (TIA), and an analog converter to digital (ADC).

[0071] 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.

[0072] It is explained here that the packaging form of the above-mentioned optical module or optical component 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. Or, a butterfly package. For example, a box (BOX) with a square shell can be used for packaging. Alternatively, the optical component can also be a chip on board (COB) package.

[0073] 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 the same fiber, and they can be reasonably set according to actual conditions.

[0074] Exemplarily, the optical component may be any one of a unidirectional optical component, a bidirectional optical component, a tridirectional optical component, a quadridirectional optical component, and the like.

[0075] Alternatively, illustratively, the optical component may also be a single-fiber or multi-fiber optical component.

[0076] For example, the optical component may include an optical-electrical combo optical component.

[0077] 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.

[0078] It is explained here that the laser may be a bare laser chip, or a packaged laser, or the above-mentioned laser diode. The embodiments of the present application do not limit this.

[0079] like Figure 3 As shown, 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. That is, along a first direction y, the N-type waveguide layer 201, the active layer 300 and the P-type waveguide layer 202 are stacked in sequence, wherein the first direction y is the thickness direction of the N-type waveguide layer 201.

[0080] 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.

[0081] 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.

[0082]

[0083] dI th / dT=I th / T0 (2)

[0084] When the laser 100 is in a high temperature environment (for example, the temperature is greater than 70°C), the performance will be reduced, which is 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, and ultimately cause the laser 100 to fail.

[0085] Taking a red laser as an example, the material of the active layer 300 includes aluminum gallium indium phosphide (AlInGaP).

[0086] like Figure 4 As shown, Figure 4 Indicate Figure 3 The band structure of the laser shown, Figure 4 The horizontal axis represents Figure 3 The position coordinates of the laser 100 in the first direction y are shown in μm, and the ordinate represents the energy band size at the corresponding position in eV. Figure 4 It can be seen that the electron confinement capability is limited in the active layer 300 of the laser 100. The thermal conductivity of the AlGaInP material is relatively low (e.g., the thermal conductivity is 6 W·m -1 ·K -1 ~10W·m -1 ·K -1 ), and the well depth of the quantum well layer 310 is relatively shallow. This easily causes serious leakage of electrons at high temperatures, resulting in laser power saturation and roll-off, causing the performance of the red laser to deteriorate at high temperatures, and making it difficult to optimize the epitaxial structure of the laser 100.

[0087] In addition, compared with a distributed feedback laser (DFB), the laser 100 does not have a filtering structure such as a grating, so that the means for controlling T0 are limited.

[0088] Based on this, in order to improve the high temperature reliability of the laser, the embodiment of the present application also provides a laser. Figure 5 As shown, 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. The active layer 300 includes at least one quantum well layer 310 and a plurality of quantum barrier layers 320, the quantum well layer 310 and the quantum barrier layer 320 are overlapped, and 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 plurality of quantum barrier layers.

[0089] 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 the leakage of carriers.

[0090] like Fig. 6A As shown, 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 .

[0091] 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. The first direction is the thickness direction of the substrate 110 .

[0092] The material of the substrate 110 may include gallium arsenide (GaAs), for example. For example, the substrate 110 may be doped with silicon (Si) material.

[0093] Exemplarily, the material of the substrate 110 may include a semiconductor doped with an N-type material or a P-type material.

[0094] like Fig. 6A As shown, the first waveguide layer 210 is disposed on the substrate 110 .

[0095] 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.

[0096] The first waveguide layer 210 may be an N-type waveguide layer doped with an N-type material, or may be a P-type waveguide layer doped with a P-type material.

[0097] The doping of the first waveguide layer 210 may be, for example, unintentional doping (UID).

[0098] 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 is in the range of 50 nm to 250 nm. For example, the size may be 60 nm, 89 nm, 103 nm, 146 nm, 160 nm, 178 nm, 200 nm or 234 nm.

[0099] Continue to refer Fig. 6A The active layer 300 is disposed on a side of the first waveguide layer 210 away from the substrate 110 .

[0100] That is, the active layer 300 is disposed on a surface of the first waveguide layer 210 away from the substrate 110 .

[0101] 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 electric current, and constitutes the light-emitting region of the laser 100 .

[0102] Exemplarily, the laser 100 may further include at least two electrodes ( Fig. 6A not shown).

[0103] After the electrodes are connected to the positive and negative electrodes of the power supply, the current is input to the active layer 300 through the electrodes, and electrons and holes are formed in the active layer 300. At this time, the electrons and holes in the active layer 300 recombine to generate photons. At the same time, a particle number inversion is formed in the active layer 300, that is, the 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 can be greater than the number of particles in the low-energy valence band. When the current is continuously injected, the electrons in the high-energy conduction band transition to the low-energy valence band, forming stimulated radiation light amplification in the active layer 300. When stimulated radiation occurs, photons reflect back and forth in the active layer 300, and generate stimulated radiation with the stimulated particles. The light amplification process is repeated continuously, the photons are enhanced, and finally a laser is formed and output from the light outlet.

[0104] 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.

[0105] Exemplarily, the active layer 300 includes a quantum well layer 310, and then 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.

[0106] 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.

[0107] 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.

[0108] For example, the materials of the multiple quantum well layers 310 may have the same composition or different compositions.

[0109] Exemplarily, the materials of the plurality of quantum barrier layers 320 are different in composition.

[0110] 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.

[0111] 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 layer less than the number of quantum barrier layers 320.

[0112] 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. Fig. 6A As shown, 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.

[0113] For convenience, Fig. 6A As shown, 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 .

[0114] 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 .

[0115] Each quantum barrier layer 320 and each quantum well layer 310 are introduced and described in sequence below.

[0116] The material of the quantum barrier layer QB1 includes Al 0.357 In 0.553 Ga 0.09P. The stress of the quantum barrier layer QB1 on the substrate 110 is 0. That is, there is no tensile stress or compressive stress on the substrate 110 from the quantum barrier layer QB1. The thickness of the quantum barrier layer QB1 is 5nm to 20nm. For example, the thickness of the quantum barrier layer QB1 can be 6nm, 8nm, 10nm, 12nm, 15nm or 19nm, etc.

[0117] 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 of the application.

[0118] It is noted here 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 .

[0119] The doping of the quantum barrier layer QB1 is unintentional doping.

[0120] The material of the quantum well layer QW1 includes Al0In 0.68 Ga 0.32 P. The stress of the quantum well layer QW1 on the substrate 110 is 14101. That is, the quantum well layer QW1 has a certain tensile stress on the substrate 110. Here, a positive stress represents the presence of tensile stress, and a negative stress represents the presence of compressive stress. The thickness of the quantum well layer QW1 is 1nm to 6nm. For example, the thickness of the quantum well layer QW1 can be 2nm, 3nm, 4nm or 6nm.

[0121] The doping of the quantum well layer QW1 is unintentional doping.

[0122] In some embodiments, the quantum well layer QW1 and the first waveguide layer 210 are an integral structure.

[0123] The material of the quantum barrier layer QB2 includes Al 0.22 In 0.46 Ga 0.32 P. The stress of the quantum barrier layer QB2 on the substrate 110 is -9582. That is, the quantum barrier layer QB2 has a certain compressive stress on the substrate 110. The thickness of the quantum barrier layer QB2 is 5nm to 20nm. For example, the thickness of the quantum barrier layer QB2 can be 6nm, 8nm, 10nm, 12nm, 15nm or 19nm.

[0124] The doping of the quantum barrier layer QB2 is unintentional doping.

[0125] The material of the quantum well layer QW2 includes Al0In 0.68 Ga 0.32P. The stress of the quantum well layer QW2 on the substrate 110 is 14101. That is, the quantum well layer QW2 has a certain tensile stress on the substrate 110. The thickness of the quantum well layer QW2 is 1nm to 6nm. For example, the thickness of the quantum well layer QW2 can be 2nm, 3nm, 4nm or 6nm.

[0126] The doping of the quantum well layer QW2 is unintentional doping.

[0127] In some embodiments, the material composition, thickness, and stress of the quantum well layer QW1 and the quantum well layer QW2 are the same, that is, the band gap of the quantum well layer QW1 and the band gap of the quantum well layer QW2 are the same.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] The material of the quantum barrier layer QB3 includes Al 0.45 In 0.46 Ga 0.09 P. The stress of the quantum barrier layer QB3 on the substrate 110 is -5983. That is, there is no tensile stress or compressive stress in the quantum barrier layer QB3 on the substrate 110. The thickness of the quantum barrier layer QB3 is 5nm to 20nm. For example, the thickness of the quantum barrier layer QB3 can be 6nm, 8nm, 10nm, 11nm, 12nm, 15nm or 19nm, etc.

[0132] 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 the present embodiment of the application.

[0133] 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 .

[0134] The doping of the quantum barrier layer QB3 is unintentional doping.

[0135] Continue to refer Fig. 6A The second waveguide layer 220 is disposed on a side of the active layer 300 away from the substrate 110 .

[0136] That is, the second waveguide layer 220 is disposed on the surface of the active layer 300 away from the substrate 110 .

[0137] For example, the material of the second waveguide layer 220 includes AlInGaP. 0.357 In 0.553 Ga 0.09 P.

[0138] 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 also be a P-type waveguide layer doped with a P-type material. This embodiment of the present application does not limit this.

[0139] It is explained here 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 .

[0140] 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.

[0141] The doping of the second waveguide layer 220 may be, for example, unintentional doping.

[0142] 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 is in the range of 50 nm to 250 nm. For example, the size may be 60 nm, 89 nm, 103 nm, 136 nm, 150 nm, 160 nm, 178 nm, 200 nm, or 234 nm.

[0143] 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.

[0144] 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.

[0145] Correspondingly, the material types doped into the substrate 110 and the quantum barrier layer QB1 are both N-type materials, and the material types doped into the quantum barrier layer QB3 are both P-type materials.

[0146] 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.

[0147] 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.

[0148] Correspondingly, the material types doped into the substrate 110 and the quantum barrier layer QB1 are P-type materials, and the material types doped into the quantum barrier layer QB3 are all N-type materials.

[0149] 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 the multiple 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.

[0150] That is, the quantum barrier layer 320 closest to the P-type waveguide layer 202 has the largest band gap.

[0151] The embodiments of the present application do not limit this, and can be reasonably set according to actual conditions.

[0152] 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.

[0153] 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 .

[0154] That is, the band gap of the quantum barrier layer 320 closest to the second waveguide layer 220 is the largest.

[0155] For example, Figure 6B As shown, the multiple quantum barrier layers 320 include a first quantum barrier layer 321 and a second quantum barrier layer 322. 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). The band gap of the second quantum barrier layer 322 is not less than the band gap of the first quantum barrier layer 321.

[0156] 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 .

[0157] In other words, the band gap of any quantum barrier layer 320 among the multiple quantum barrier layers 320 is not less 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 ).

[0158] In some embodiments, along the direction from the first waveguide layer 210 to the second waveguide layer 220 , the band gap of the quantum barrier layer 320 gradually increases.

[0159] That is, along the direction from the N-type waveguide layer 201 to the P-type waveguide layer 202 , the band gap of the quantum barrier layer 320 gradually increases.

[0160] 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 .

[0161] Exemplarily, 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 .

[0162] As Fig. 6A Taking the laser 100 shown in FIG. 1 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 .

[0163] 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 close to the first waveguide layer 210 .

[0164] That is, 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 greater than or equal to the band gap of the quantum barrier layer 320 close to the first waveguide layer 210 .

[0165] That is, E QB1 ≤E QB2 ≤E QB3 ≤……≤E QB(i-1) .

[0166] 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.

[0167] 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 .

[0168] 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 .

[0169] That is, E QB1 =EQB2 =E QB3 =……=E QB(i-1) <E QBi .

[0170] Alternatively, illustratively, along the direction from the first waveguide layer 210 to the second waveguide layer 220, the band gap of the quantum barrier layer 320 may be equal first and then increase. Alternatively, it may be increased first, with the band gap of the middle part of the quantum barrier layer 320 being equal, and the band gap of the part of the quantum barrier layer 320 close to the second waveguide layer 220 increasing.

[0171] 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).

[0172] That is, E QB1 ≤E QB2 ≤E QB3 ≤……≤E QB(i-1) <E QBi .

[0173] The material of the quantum barrier layer 320 includes any one of AlGaAs and AlGaInP.

[0174] Exemplarily, 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.

[0175] Figure 7 Indicate Fig. 6A The band structure of the laser is shown. Figure 7 The horizontal axis represents Fig. 6A The position coordinates of the laser 100 in the first direction y are shown in μm, and the ordinate represents the energy band size at the corresponding position in eV. Figure 7It can be seen that the band structure forms an equivalent potential barrier at the position closest to the P-type waveguide layer 202 to block electrons and thereby suppress the leakage of carriers, which can improve the performance of the laser 100 in a high temperature environment and enhance the high temperature reliability of the laser 100 .

[0176] Regarding the quantum well layers 310 , in some embodiments, the band gaps of the plurality of quantum well layers 310 in the active layer 300 are equal.

[0177] Exemplarily, 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, ..., the quantum well layer QWj are arranged in sequence. QW1 =E QW2 =E QW3 =……=E QWj .

[0178] As Fig. 6A Taking the laser 100 shown in FIG. 1 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 .

[0179] In some 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 .

[0180] That is, the band gap of the quantum well layer 310 closest to the second waveguide layer 220 is the largest.

[0181] 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.

[0182] That is, along the direction from the N-type waveguide layer to the P-type waveguide layer, the band gap of the quantum well layer 310 gradually increases.

[0183] That is, E QW1 <E QW2 <E QW3 <…… <E QWj .

[0184] As Fig. 6A Taking the laser 100 shown in FIG. 1 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 .

[0185] Alternatively, illustratively, the band gap of any quantum well layer 310 among the plurality of 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 .

[0186] That is, 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 greater than or equal to the band gap of the quantum well layer 310 close to the first waveguide layer 210 .

[0187] That is, E QW1 ≤E QW2 ≤E QW3 ≤……≤E QW(j-1) .

[0188] 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 equal.

[0189] 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 .

[0190] 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 .

[0191] That is, E QW1 =E QW2 =E QW3 =……=E QW(j-1) <E QWj .

[0192] 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).

[0193] That is, E QW1 ≤E QW2 ≤E QW3 ≤……≤E QW(j-1) <E QWj .

[0194] For example, the material of the quantum well layer 310 may include AlInGaP, wherein the composition of In 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.

[0195] 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.

[0196] 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.

[0197] 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, j=i-1.

[0198] 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 , and can be reasonably set according to actual conditions. It is only necessary 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 .

[0199] 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 .

[0200] Since the band gaps of the quantum well layer 310 and the quantum barrier layer 320 are different, the quantum well layer 310 and the quantum barrier layer 320 have stress relative to the substrate 110. For example, tensile stress or compressive stress. In order to alleviate the stress caused by the band gap and ensure the performance of the laser 100, illustratively, the sum of the stress of all the quantum well layers 310 and the stress of all the quantum barrier layers 320 is less than 200 ppm.

[0201] 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.

[0202] C=ε·d (3)

[0203] In some embodiments, continue to refer to Fig. 6A The laser 100 further includes a first confinement layer 410 and a second confinement layer 420 .

[0204] The first limiting layer 410 and the second limiting layer 420 function to limit the optical waveguide, concentrate the current, increase the current density, and further improve the light emission uniformity of the laser 100 .

[0205] like Fig. 6A As shown, the first confinement layer 410 is disposed on the side of the first waveguide layer 210 away from the active layer 300 . In other words, the first confinement layer 410 is disposed on the side of the N-type waveguide layer 201 away from the active layer 300 .

[0206] In other words, the first confinement layer 410 is disposed between the first waveguide layer 210 and the substrate 110 .

[0207] For example, the material of the first confinement layer 410 may include Al 0.46 In 0.5 Ga 0.04 P.

[0208] The stress of the first confinement layer 410 is 0. That is, the first confinement layer 410 does not exert tensile stress or compressive stress on the substrate 110 .

[0209] Exemplarily, the thickness of the first restriction layer 410 is 600 nm to 1500 nm. For example, the thickness of the first restriction layer 410 may be 650 nm, 850 nm, 1000 nm, 1160 nm, 1379 nm, or 1480 nm.

[0210] The first limiting layer 420 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.

[0211] It is explained here 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 .

[0212] 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.

[0213] For example, the doping concentration of the first confinement layer 410 is 5×10 18 cm -3 .

[0214] like Fig. 6A As shown, the second confinement layer 420 is disposed on the side of the second waveguide layer 220 away from the active layer 300. That is, the second confinement layer 420 is disposed on the side of the P-type waveguide layer 202 away from the active layer 300.

[0215] For example, the material of the second confinement layer 420 may include Al 0.5 In0.5 Ga0P.

[0216] The stress of the second confinement layer 420 is 0. That is, the second confinement layer 420 does not exert tensile stress or compressive stress on the substrate 110 .

[0217] Exemplarily, the thickness of the second restriction layer 420 is 600 nm to 1200 nm. For example, the thickness of the second restriction layer 420 may be 650 nm, 850 nm, 1000 nm, 1160 nm, or 1180 nm.

[0218] The second confinement layer 420 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.

[0219] It is explained here 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 .

[0220] 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.

[0221] For example, the doping concentration of the second confinement layer 420 is 2×10 18 cm -3 .

[0222] 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.

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

[0225] 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.

[0226] 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.

[0227] In some embodiments, Figure 8As shown, the laser 100 further includes a first bandgap transition layer 510 .

[0228] The first bandgap transition layer 510 is disposed between the substrate 110 and the first confinement layer 410 .

[0229] For example, the material of the first bandgap transition layer 510 may include Al 0.4 Ga 0.6 As or Al 0.3 In 0.5 Ga 0.2 P.

[0230] 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 may be 15 nm, 20 nm, 30 nm, 44 nm, or 57 nm.

[0231] 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 the present embodiment.

[0232] It is noted here 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 .

[0233] That is, the doping material of the first bandgap transition layer 510 , the material type of the first confinement layer 410 , the material type of the quantum barrier layer QB1 , and the material type of the first waveguide layer 210 are all the same.

[0234] For example, the doping concentration of the first bandgap transition layer 510 is 8×10 18 cm -3 .

[0235] In some embodiments, Figure 8 As shown, the laser 100 further includes a second bandgap transition layer 520 .

[0236] The second bandgap transition layer 520 is disposed on a side of the second confinement layer 420 away from the substrate 110 .

[0237] 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.

[0238] 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 may be 15 nm, 20 nm, 30 nm, 44 nm, or 57 nm.

[0239] 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.

[0240] It is noted here 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 .

[0241] That is, the doping material of the second bandgap transition layer 520 , the material type of the second confinement layer 420 , the material type of the quantum barrier layer QB3 , and the material type of the second waveguide layer 220 are all the same.

[0242] For example, the doping concentration of the first bandgap transition layer 510 is 8×10 18 cm -3 .

[0243] 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.

[0244] 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.

[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 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.

[0246] 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.

[0247] 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.

[0248] Continue to refer Figure 8 In some embodiments, the laser 100 further includes a third confinement layer 430 .

[0249] 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 .

[0250] like Figure 8As shown, the third restriction layer 430 is disposed on a side of the second restriction layer 420 close to the substrate 110 .

[0251] For example, the material of the third confinement layer 430 may include Al 0.5 In 0.5 Ga0P.

[0252] The stress of the third confinement layer 430 is 0. That is, the third confinement layer 430 does not exert tensile stress or compressive stress on the substrate 110 .

[0253] Exemplarily, the thickness of the third restriction layer 430 is 0 nm to 200 nm. For example, the thickness of the third restriction layer 430 may be 40 nm, 65 nm, 85 nm, 100 nm, 160 nm, or 190 nm.

[0254] The third limiting layer 430 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.

[0255] It is explained here 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 .

[0256] 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.

[0257] For example, the doping concentration of the third confinement layer 430 is 2×10 18 cm -3 .

[0258] For example, Figure 8 As shown, the laser 100 further includes an etch stop layer (ESL) 610 .

[0259] The etch stop layer 610 is disposed on a side of the third confinement layer 430 away from the substrate 110 .

[0260] like Figure 8 As shown, the etch stop layer 610 is disposed between the second confinement layer 420 and the third confinement layer 430 .

[0261] For example, the material of the etch stop layer 610 may include Al0In 0.5 Ga 0.5 P.

[0262] The stress of the etch stop layer 610 is 0. That is, the etch stop layer 610 does not exert tensile stress or compressive stress on the substrate 110 .

[0263] 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 may be 14 nm, 20 nm, 27 nm, 36 nm, 40 nm, or 49 nm.

[0264] The etching stop layer 610 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 of the application.

[0265] It is explained here 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 .

[0266] 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.

[0267] For example, the doping concentration of the etch stop layer 610 is 2×10 18 cm -3 .

[0268] For example, Figure 8 As shown, the laser 100 further includes a contact layer 710 .

[0269] The contact layer 710 is disposed on a side of the third restriction layer 430 away from the substrate 110 .

[0270] like Figure 8 As shown, the contact layer 710 is disposed on the side of the second bandgap transition layer 520 away from the substrate 110 .

[0271] By way of example, the material of the contact layer 710 may include GaAs.

[0272] Exemplarily, the thickness of the contact layer 710 is 50 nm to 250 nm. For example, the thickness of the contact layer 710 may be 64 nm, 86 nm, 127 nm, 178 nm, 200 nm, or 235 nm.

[0273] The contact layer 710 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.

[0274] It is explained here 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 .

[0275] 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.

[0276] For example, the doping concentration of the etch stop layer 610 is 8×10 18 cm -3 .

[0277] This completes the introduction of the laser 100 provided in the embodiment of the present application.

[0278] 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.

[0279] 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.

[0280] 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.

[0281] 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.

[0282] The laser 100 provided in the embodiment of the present application comprises 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 comprises 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. The band gap of the quantum barrier layer 320 closest to the P-type waveguide layer 201 is greater than the band gaps of the remaining quantum barrier layers 320 in the plurality of 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 improving the performance of the laser 100.

[0283] Taking the example that the first waveguide layer 210 of the laser 100 is doped with an N-type material and the second waveguide layer 220 is doped with a P-type material, simulations are performed on different lasers, and the simulation results are described below.

[0284] Fig. 9 The threshold current (I th )’s changing trend. Fig. 9 The horizontal axis 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 show that as the temperature T increases, the threshold current I th of the changing trend. Fig. 9 The curve shown is the threshold current I of the laser th Curve of change with temperature T. Fig. 9 It can be seen that as the temperature increases, the threshold current I th Always higher than Figure 3 The threshold current I of the laser shown th .

[0285] Through simulation, it can be concluded that the characteristic temperature T0 of the laser 100 provided in the embodiment of the present application is 190.49K. Figure 3 The characteristic temperature T0 of the laser shown is 113.92 K. It can be seen that the characteristic temperature T0 of the laser provided in the embodiment of the present application is Figure 3 The characteristic temperature T0 of the laser shown is increased by at least 67%.

[0286] Fig.10The figure shows the carrier concentrations at different positions of the two lasers at room temperature (T is 300K) and high temperature (T is 364K). Fig.10 The horizontal axis 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 .

[0287] Depend on Fig.10 It can be seen that at high temperature, the carrier concentration of the laser 100 provided in the embodiment of the present application is higher than Figure 3 At room temperature, the carrier concentration of the laser 100 provided in the embodiment of the present application is higher than Figure 3 The carrier concentration of the laser is shown in FIG. That is, in comparison, the carrier concentration of the laser 100 provided in the embodiment of the present application is high.

[0288] 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 least electron leakage. At high temperature (364K), the laser 100 provided by the embodiment of the present application has the highest electron concentration and the least electron leakage.

[0289] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope 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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