A laser, a manufacturing method and an optical module

Abstract

The application provides a laser, a preparation method and an optical module, which comprise a substrate, an N electrode arranged on a first surface of the substrate, an active region arranged on a second surface of the substrate, the second surface being arranged opposite to the first surface, a ridge waveguide arranged above the active region, a buried layer arranged on both sides of the ridge waveguide and above the active region, and a P electrode arranged above the ridge waveguide and the buried layer, wherein the ridge waveguide comprises a specially designed layer arranged above the active region, and the specially designed layer is used for changing the light field distribution; and a contact layer arranged above the specially designed layer. According to the application, the specially designed layer can be used for changing the light field distribution, so that the active region does not need to be etched in the process of preparing the ridge waveguide on the laser, and thus the probability of oxidation of aluminum gallium indium arsenic due to exposure to air is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical communication technology, and in particular to a laser, a preparation method and an optical module. BACKGROUND

[0002] With the rapid development of the Internet of Things, big data and cloud computing technology, the data communication required for information interaction presents an explosive growth, and the optical fiber communication technology emerging as the times require has become the preferred technology for realizing high-speed information transmission. With the rapid development of optical fiber communication, single-mode and high-speed direct modulation lasers have become mainstream optical devices in the field of optical communication and are key devices for long-distance and large-capacity optical fiber communication.

[0003] The DFB (distributed feedback semiconductor laser) laser, i.e., the distributed feedback semiconductor laser, is a commonly used laser in optical fiber communication. The DFB laser realizes single-mode output by coupling and mode selection of light through a periodically distributed grating inside the laser. When designing the waveguide structure of the DFB laser, two factors need to be considered. One is to effectively limit the lateral expansion of the current and the lateral diffusion of the carriers to reduce the threshold current and improve the current injection efficiency. The other is to have a good spot mode to improve the coupling efficiency of the device and the optical fiber.

[0004] The waveguide structures commonly used in semiconductor lasers at present mainly include ridge waveguide structures and buried ridge stripe structures. The ridge waveguide structure is relatively simple to manufacture, but the current is not effectively limited in the lateral direction, which is not conducive to reducing the threshold current. At the same time, the quality of the spot mode of this waveguide structure is not good, which is not conducive to improving the output power and the coupling efficiency. The buried ridge stripe structure is more complex to manufacture than the ridge waveguide structure, but it improves the symmetry of the spot mode and can suppress the emergence of high-order modes. In addition, the current blocking region formed by the InP material doped with Fe can limit the current. In addition, high-speed direct modulation lasers generally use aluminum gallium indium arsenide (AlGaInAs) material structures. The waveguide laser of aluminum gallium indium arsenide has an aluminum-containing active region exposed to the air and is prone to oxidation. The traditional buried structure laser needs to be etched to the active region, which greatly increases the probability of oxidation of aluminum gallium indium arsenide due to exposure to the air. SUMMARY

[0005] The embodiments of the present application provide a laser, a preparation method and an optical module, which reduce the probability of oxidation of aluminum gallium indium arsenide due to exposure to the air.

[0006] In a first aspect, the present application provides a laser for an optical module, comprising:

[0007] a substrate;

[0008] an N electrode disposed on a first surface of the substrate;

[0009] an active region disposed on a second surface of the substrate, the second surface being opposite to the first surface;

[0010] a ridge waveguide disposed above the active region;

[0011] a buried layer disposed on both sides of the ridge waveguide and above the active region;

[0012] a P electrode disposed above the ridge waveguide and the buried layer;

[0013] wherein the ridge waveguide comprises:

[0014] a specially designed layer disposed above the active region, the specially designed layer being used to change light field distribution;

[0015] a contact layer disposed above the specially designed layer.

[0016] In a second aspect, the application provides a laser preparation method for preparing the laser of the first aspect, the method comprising:

[0017] forming an active region on a second surface of a substrate;

[0018] disposing a specially designed layer and a contact layer on the active region in sequence;

[0019] disposing a contact layer on the specially designed layer, etching the specially designed layer and the contact layer by using the mask to form a ridge waveguide;

[0020] growing a buried layer on both sides of the ridge waveguide;

[0021] disposing a P electrode above the buried layer and the ridge waveguide;

[0022] disposing an N electrode on a first surface of the substrate.

[0023] In a third aspect, the application provides an optical module, comprising:

[0024] a circuit board;

[0025] an optical emission component electrically connected to the circuit board, used to generate and output signal light, comprising a laser;

[0026] wherein the laser comprises the laser of the first aspect or the laser prepared by the preparation method of the second aspect.

[0027] The application provides a laser, a preparation method and an optical module, wherein a ridge waveguide is arranged above an active region, buried layers are arranged on two sides of the ridge waveguide, and the ridge waveguide comprises a contact layer and a specially designed layer. In the laser provided by the application, the specially designed layer can be used to change the light field distribution, so that the active region does not need to be etched in the process of preparing the ridge waveguide on the laser, thereby reducing the probability of oxidation of aluminum gallium indium arsenide due to exposure to air. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the application, the drawings required in the embodiments will be briefly introduced as follows. Obviously, for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0029] Figure 1 It is a schematic diagram of an optical communication terminal connection relationship;

[0030] Figure 2 It is a schematic diagram of an optical network terminal structure;

[0031] Figure 3 It is a schematic diagram of an optical module structure provided by the embodiment of the application;

[0032] Figure 4 It is a schematic diagram of an optical module disassembly structure provided by the embodiment of the application;

[0033] Figure 5 It is a schematic diagram of an internal structure of an optical module provided by the embodiment of the application;

[0034] Figure 6 It is an appearance structure diagram of an optical transmitting sub-module provided by the embodiment of the application;

[0035] Figure 7 It is a schematic diagram of a structure in which a pipe base and a pipe cap are separated in an optical transmitting component provided by the embodiment of the application;

[0036] Figure 8 It is a schematic diagram of a cross-sectional structure of a laser provided by the embodiment of the application;

[0037] Figure 9 It is a schematic diagram of a structure in which an active region is formed on a substrate provided by the embodiment of the application;

[0038] Figure 10 It is a schematic diagram of a structure in which a ridge waveguide layer is formed on an active region provided by the embodiment of the application;

[0039] Figure 11 It is a schematic diagram of a structure in which a ridge waveguide is etched provided by the embodiment of the application;

[0040] Figure 12A structure schematic diagram of forming long buried layers on both sides of a ridge waveguide is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described in combination 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 of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0042] One of the core links of optical fiber communication is the mutual conversion of optical signals and electrical signals. Optical fiber communication uses optical signals carrying information to transmit in information transmission equipment such as optical fibers / optical waveguides, and the passive transmission characteristics of light in optical fibers / optical waveguides can be used to realize low-cost and low-loss information transmission; and the information processing equipment such as computers uses electrical signals. In order to establish information connection between the information transmission equipment such as optical fibers / optical waveguides and the information processing equipment such as computers, it is necessary to realize the mutual conversion of electrical signals and optical signals.

[0043] The optical module realizes the mutual conversion function of optical signals and electrical signals in the field of optical fiber communication technology, and the mutual conversion of optical signals and electrical signals is the core function of the optical module. The optical module realizes electrical connection between the external host computer through the gold fingers on the internal circuit board of the optical module, and the main electrical connection includes power supply, I2C signal, data signal and ground. The electrical connection mode realized by the gold fingers has become the mainstream connection mode in the optical module industry, and the definition of the pins on the gold fingers forms various industry protocols / specifications.

[0044] Figure 1 A schematic diagram of optical communication terminal connection relationship is shown in FIG. 1. As shown in FIG. 1, the connection of the optical communication terminal mainly includes the mutual connection among the optical network terminal 100, the optical module 200, the optical fiber 101 and the network cable 103. Figure 1

[0045] One end of the optical fiber 101 is connected to a remote server, and one end of the network cable 103 is connected to a local information processing equipment. The connection between the local information processing equipment and the remote server is completed by the connection of the optical fiber 101 and the network cable 103, and the connection between the optical fiber 101 and the network cable 103 is completed by the optical network terminal 100 with the optical module 200.

[0046] ​The optical port of the optical module 200 externally accesses the optical fiber 101, and a bidirectional optical signal connection is established with the optical fiber 101; the electrical port of the optical module 200 externally accesses the optical network terminal 100, and a bidirectional electrical signal connection is established with the optical network terminal 100; the mutual conversion of optical signals and electrical signals is realized in the optical module, thereby establishing an information connection between the optical fiber and the optical network terminal; specifically, the optical signal from the optical fiber is converted into an electrical signal by the optical module and then input into the optical network terminal 100, and the electrical signal from the optical network terminal 100 is converted into an optical signal by the optical module and then input into the optical fiber.

[0047] The optical network terminal has an optical module interface 102 for accessing the optical module 200 and establishing a bidirectional electrical signal connection with the optical module 200; the optical network terminal has a network cable interface 104 for accessing the network cable 103 and establishing a bidirectional electrical signal connection with the network cable 103; a connection is established between the optical module 200 and the network cable 103 through the optical network terminal 100, and specifically, the optical network terminal transmits signals from the optical module to the network cable and transmits signals from the network cable to the optical module, and the optical network terminal serves as the upper computer of the optical module to monitor the operation of the optical module.

[0048] At this point, a bidirectional signal transmission channel is established between the remote server and the local information processing device through the optical fiber, the optical module, the optical network terminal, and the network cable.

[0049] Common information processing devices include routers, switches, electronic computers, etc.; the optical network terminal is the upper computer of the optical module, which provides data signals to the optical module and receives data signals from the optical module, and common optical module upper computers also include optical line terminals, etc.

[0050] Figure 2 The optical network terminal is a structural schematic diagram. As shown in Figure 2 The optical network terminal 100 has a circuit board 105, and a cage 106 is arranged on the surface of the circuit board 105; an electrical connector is arranged inside the cage 106 for accessing the gold fingers and other electrical ports of the optical module; a heat sink 107 is arranged on the cage 106, and the heat sink 107 has fins and other protrusions that increase the heat dissipation area.

[0051] The optical module 200 is inserted into the optical network terminal, specifically: the electrical port of the optical module is inserted into the electrical connector inside the cage 106, and the optical port of the optical module is connected with the optical fiber 101.

[0052] The cage 106 is located on the circuit board, and the electrical connector on the circuit board is wrapped in the cage, so that the electrical connector is arranged inside the cage; the optical module is inserted into the cage, and the optical module is fixed by the cage; the heat generated by the optical module is conducted to the cage 106, and then diffused through the heat sink 107 on the cage.

[0053] Currently, fifth-generation mobile communication technology (5G) meets the growing demand for high-speed wireless transmission. 5G communication uses a much higher spectrum than 4G communication, which greatly increases the communication speed of 5G communication, but also significantly increases the transmission attenuation of the signal.

[0054] The new service characteristics and higher performance requirements of 5G have posed new challenges to the bearer network architecture and technical solutions at all layers. Optical modules, as the basic components of the 5G network physical layer, are also facing technological innovation and upgrades. This is mainly reflected in the fact that optical modules used in 5G transmission need to have two basic technical characteristics: high-speed transmission and low return loss. To meet the demand for optical modules in 5G communication networks, the embodiments of the present application provide an optical module.

[0055] Figure 3 A schematic diagram of the structure of an optical module provided in an embodiment of the present application is shown. Figure 4 The present invention provides a schematic diagram of the decomposition structure of an optical module. Figure 3 、 Figure 4 As shown, the optical module 200 provided in the embodiment of the present application includes an upper shell 201 , a lower shell 202 , a circuit board 203 , a round square tube 300 , a light emitting component 400 and a light receiving component 500 .

[0056] The upper shell 201 is covered on the lower shell 202 to form a wrapping cavity with two openings; the outer contour of the wrapping cavity is generally square. Specifically, the lower shell includes a main board and two side panels located on both sides of the main board and perpendicular to the main board; the upper shell includes a cover plate, which is covered on the two side panels of the upper shell to form a wrapping cavity; the upper shell may also include two side walls located on both sides of the cover plate and perpendicular to the cover plate, and the two side walls are combined with the two side panels to realize the upper shell covering the lower shell.

[0057] The two openings can be two end openings (204, 205) in the same direction, or two openings in different directions; one of the openings is the electrical port 204, and the gold finger of the circuit board extends from the electrical port 204 and is inserted into a host computer such as an optical network terminal; the other opening is the optical port 205, which is used for external optical fiber access; the optoelectronic devices such as the circuit board 203, the square tube body 300, the light emitting component 400 and the light receiving component 500 are located in the encapsulated cavity formed by the upper and lower shells.

[0058] The upper shell 201 and the lower shell 202 are combined to facilitate the installation of the round-square tube 300, the light emitting component 400, the light receiving component 500 and other devices into the shell, and the upper shell 201 and the lower shell 202 form the outermost encapsulation protective shell of the optical module; the upper shell 201 and the lower shell 202 are generally made of metal material, which is beneficial to electromagnetic shielding and heat dissipation; generally, the shell of the optical module is not made into an integral component, so that the positioning component, the heat dissipation component and the electromagnetic shielding component cannot be installed when assembling the circuit board and other devices, and it is not conducive to production automation.

[0059] Generally, the optical module 200 further includes an unlocking component located on the outer wall of the wrapping cavity / lower shell 202, which is used to realize the fixed connection between the optical module and the upper computer or to release the fixed connection between the optical module and the upper computer.

[0060] The unlocking component has a clamping component matched with the cage of the upper computer; the end of the unlocking component can be pulled to relatively move the unlocking component on the surface of the outer wall; the optical module is inserted into the cage of the upper computer, and the clamping component of the unlocking component fixes the optical module in the cage of the upper computer; by pulling the unlocking component, the clamping component of the unlocking component moves, and then the connection relationship between the clamping component and the upper computer is changed to release the clamping relationship between the optical module and the upper computer, so that the optical module can be pulled out of the cage of the upper computer.

[0061] The circuit board 203 is provided with circuit traces, electronic components (such as capacitors, resistors, transistors, MOS tubes) and chips (such as MCUs, clock data recovery CDRs, power management chips, data processing chips DSPs).

[0062] The circuit board 203 connects the electrical devices in the optical module together according to the circuit design through the circuit traces to realize the functions of power supply, electrical signal transmission and grounding.

[0063] The circuit board 203 is generally a hard circuit board, and the hard circuit board can also realize the bearing function due to its relatively hard material, such as the hard circuit board can stably bear the chip; when the optical transceiver is located on the circuit board, the hard circuit board can also provide stable bearing; the hard circuit board can also be inserted into the electrical connector in the cage of the upper computer, specifically, a metal pin / gold finger is formed on the surface of the end of one side of the hard circuit board, which is used to connect with the electrical connector; these are not convenient to realize by the flexible circuit board.

[0064] Part of the optical modules also use flexible circuit boards as a supplement to the hard circuit board; the flexible circuit board is generally used in cooperation with the hard circuit board, such as the flexible circuit board can be used to connect between the hard circuit board and the optical transceiver.

[0065] The light emitting component and the light receiving component can be collectively referred to as an optical sub-module. Figure 4As shown, in the optical module provided by this embodiment, the light emitting component 400 and the light receiving component 500 are both arranged on the round square tube body 300, the light emitting component 400 is used to generate and output signal light, and the light receiving component 500 is used to receive signal light from outside the optical module. An optical fiber adapter is provided on the round square tube body 300, and the optical fiber adapter is used to realize the connection between the optical module and the external optical fiber, and a lens assembly is usually provided in the round square tube body 300, and the lens assembly is used to change the propagation direction of the signal light output by the light emitting component 400 or the signal light input by the external optical fiber. The light emitting component 400 and the light receiving component 500 are physically separated from the circuit board 203, so it is difficult for the light emitting component 400 and the light receiving component 500 to be directly connected to the circuit board 203, so in the embodiment of the present application, the light emitting component 400 and the light receiving component 500 are electrically connected respectively through a flexible circuit board. However, in the embodiment of the present application, the assembly structure of the light emitting component 400 and the light receiving component 500 is not limited to Figure 3 and Figure 4 The structure shown in the figure can also be other assembled structures, such as the light emitting component 400 and the light receiving component 500 are arranged on different tubes. Figure 3 and Figure 4 The structure shown is taken as an example.

[0066] Attachment Figure 5 This is a schematic diagram of the internal structure of an optical module provided in an embodiment of the present application. Figure 5 As shown, the interior of the optical module 200 provided in the embodiment of the present application includes a square tube body 300, a light emitting component 400, and a light receiving component 500. The light emitting component 400 is arranged on the square tube body 300 and is coaxial with the optical fiber adapter of the square tube body 300. The light receiving component 500 is arranged on the side of the square tube body 300 and is not coaxial with the optical fiber adapter. However, in the embodiment of the present application, the light receiving component 500 can be coaxial with the optical fiber adapter and the light emitting component 400 can be not coaxial with the optical fiber adapter. Placing the light emitting component 400 and the light receiving component 500 through the square tube body 300 not only facilitates the control of the signal light transmission optical path, but also facilitates the compact design of the optical module, reducing the space occupied by the signal light transmission optical path. In addition, with the development of wavelength division multiplexing technology, in some optical modules, more than one light emitting component 400 and light receiving component 500 are arranged on the square tube body 300.

[0067] In some embodiments of the present application, a reflective mirror is further provided in the square tube body 300, which changes the propagation direction of the signal light to be received by the light receiving component 500 or changes the propagation direction of the signal light generated by the light emitting component 400, thereby facilitating the light receiving component 500 to receive the signal light or the output of the signal light generated by the light emitting component 400.

[0068] Figure 6A light emitting component provided by an embodiment of the present application is shown in a perspective view. Figure 6 As shown in the figure, the light emitting component 400 provided by the embodiment includes a tube base 410, a tube cap 420, and other devices disposed in the tube cap 420 and the tube base 410. The tube cap 420 is arranged at one end of the tube base 410. The tube base 410 includes a plurality of tube pins. The tube pins are used to realize electrical connection between a flexible circuit board and other electrical devices in the light emitting component 400, and further realize electrical connection between the light emitting component 400 and the circuit board 203. The embodiment only takes the structure shown in the figure as an example. Figure 6

[0069] Figure 7 A structure in which a tube base and a tube cap are separated in a light emitting component provided by an embodiment of the present application is shown in a schematic view. Figure 7 As shown in the figure, the light emitting component 400 includes a laser 600. The laser 600 generates signal light, and the generated signal light transmits through the tube cap 420. The laser 600 is a DFB laser. The laser 600 realizes single-mode output by preparing a periodically distributed grating inside the laser to couple and select modes of light. AlGaInAs is preferred for high-speed laser material in the DFB laser. AlGaInAs material has good performance at high temperature, and thus can ensure performance of the DFB laser in a working process. However, because the waveguide end face of the active region formed by AlInGaAs contains aluminum, when a ridge waveguide is etched, the active region formed by AlInGaAs needs to be etched, which increases the probability that aluminum gallium indium arsenic is oxidized when exposed to air.

[0070] To avoid that the active region containing aluminum of the laser 600 is exposed to air in a process, the present application provides a new laser 600. Figure 8 A cross-sectional structure of a laser provided by an embodiment of the present application is shown in a schematic view. Figure 8 As shown in the figure, the laser 600 provided by the embodiment includes a substrate 601, an N electrode 602, an active region 603, a ridge waveguide 604, a buried layer 605, and a P electrode 606. Specifically, the substrate 601 is a base of the laser 600. The N electrode 602 is disposed on a back surface (a first surface) of the substrate 601. The active region 603 is disposed on a top surface (a second surface) of the substrate 601. The second surface and the first surface are oppositely disposed surfaces on the substrate 601. The ridge waveguide 604 is disposed above the active region 603. The buried layer 605 is disposed above the active region 603 and on both sides of the ridge waveguide 604. The P electrode 606 is disposed above the buried layer 605 and the ridge waveguide 604.

[0071] As shown in the figure, the laser 600 provided by the embodiment includes a substrate 601, an N electrode 602, an active region 603, a ridge waveguide 604, a buried layer 605, and a P electrode 606. Specifically, the substrate 601 is a base of the laser 600. The N electrode 602 is disposed on a back surface (a first surface) of the substrate 601. The active region 603 is disposed on a top surface (a second surface) of the substrate 601. The second surface and the first surface are oppositely disposed surfaces on the substrate 601. The ridge waveguide 604 is disposed above the active region 603. The buried layer 605 is disposed above the active region 603 and on both sides of the ridge waveguide 604. The P electrode 606 is disposed above the buried layer 605 and the ridge waveguide 604. Figure 8 ​As shown, the laser 600 provided by the embodiments of the present application includes the specially designed layer 6041 and the contact layer 6042. The specially designed layer 6041 can be used to change the light field distribution, and thus the etching to the active region 603 is not needed in the process of forming the ridge waveguide 604, thereby reducing the probability of oxidation of aluminum gallium indium arsenide due to exposure to air, so as to effectively solve the aluminum oxidation problem existing in the aluminum indium gallium arsenide material with good temperature performance and modulation characteristics. The laser 600 provided by the embodiments of the present application forms a special buried structure through the ridge waveguide 604 including the specially designed layer 6041 and the contact layer 6042, which not only can obtain a good light spot mode, but also has a current automatic limiting function, and has a special significance for manufacturing a low-threshold current, high-efficiency and low-cost non-cooling high-speed direct modulation laser.

[0072] In some embodiments of the present application, the specially designed layer 6041 is grown above the active region 603, the contact layer 6042 is grown on the specially designed layer 6041, and then etching is performed according to the shape and parameter requirements of the ridge waveguide 604. The specially designed layer 6041 can be an indium gallium arsenide phosphorus (InGaAsP) layer, which is formed by epitaxial growth of InGaAsP material above the active region 603. Optionally, the band gap of the specially designed layer 6041 is 50nm-500nm. The contact layer 6042 includes P-InP and P-InGaAsP contact layers, which are formed by InP and InGaAsP on the specially designed layer 6041.

[0073] In the embodiments of the present application, the active region can be epitaxially grown on the substrate 601 by one time. Figure 9 A structure diagram of forming an active region on a substrate is provided in the embodiments of the present application. As shown in the figure, Figure 9 In some embodiments of the present application, the active region 603 includes a buffer layer 6031, a lower waveguide layer 6032, an aluminum gallium indium arsenide multi-quantum well active layer 6033, an upper waveguide layer 6034, a transition layer 6035, a protection layer 6036 and a grating layer 6037; the buffer layer 6031, the lower waveguide layer 6032, the aluminum gallium indium arsenide multi-quantum well active layer 6033, the upper waveguide layer 6034, the transition layer 6035 and the protection layer 6036 are sequentially arranged, the buffer layer 6031 is arranged above the substrate 601, and the grating layer 6037 is located in the protection layer 6036.

[0074] In some embodiments of the present application, the substrate 601 adopts InP (indium phosphide) material to form an N-InP substrate.

[0075] In some embodiments of the present application, the buffer layer 6031 is epitaxially grown on the substrate 601 by MOCVD (metal organic chemical vapor deposition) technology. The buffer layer 6031 can adopt InP material to form an N-InP buffer layer.

[0076] In some embodiments of the application, the lower waveguide layer 6032 is grown above the buffer layer 6031. Optionally, the lower waveguide layer 6032 is formed of an aluminum gallium indium arsenide material. Further, the lower waveguide layer 6032 is a graded bandgap and graded refractive index aluminum gallium indium arsenide lower waveguide layer, the refractive index and the bandgap of the lower waveguide layer 6032 vary linearly, the closer to the aluminum gallium indium arsenide multiple quantum well active layer 6033, the narrower the bandgap and the greater the refractive index of the lower waveguide layer 6032. Optionally, the bandgap of the lower waveguide layer 6032 decreases from the bandgap of the indium phosphide to the bandgap of the barrier of the active region.

[0077] In some embodiments of the application, the aluminum gallium indium arsenide multiple quantum well active layer 6033 is grown above the lower waveguide layer 6032. The aluminum gallium indium arsenide multiple quantum well active layer 6033 is formed of an aluminum gallium indium arsenide multiple quantum well structure using an aluminum gallium indium arsenide multiple quantum well material, which can effectively improve the differential gain of the quantum well, and further improve the modulation bandwidth. Optionally, the active region well number of the strain-compensated aluminum gallium indium arsenide multiple quantum well active layer 6033 is 3-10, the aluminum indium gallium arsenide well bandgap wavelength is 1.25 μm-1.36 μm, the well thickness is 5 nm-10 nm, the compressive strain is 0.5%-1.2%, the aluminum indium gallium arsenide barrier bandgap wavelength is 1.1 μm, the barrier thickness is 5-10 nm, and the tensile strain is 0.2%-0.6%.

[0078] In some embodiments of the application, the upper waveguide layer 6034 is grown above the aluminum gallium indium arsenide multiple quantum well active layer 6033. Optionally, the upper waveguide layer 6034 is formed of an aluminum gallium indium arsenide material. Further, the upper waveguide layer 6034 is a graded bandgap and graded refractive index aluminum gallium indium arsenide upper waveguide layer, the refractive index and the bandgap of the upper waveguide layer 6034 vary linearly, the closer to the aluminum gallium indium arsenide multiple quantum well active layer 6033, the narrower the bandgap and the greater the refractive index of the upper waveguide layer 6034. Optionally, the bandgap of the upper waveguide layer 6034 increases from the bandgap of the indium phosphide to the bandgap of the barrier of the active region.

[0079] In some embodiments of the application, the transition layer 6035 is grown above the upper waveguide layer 6034. The transition layer 6035 is formed of InP or InGaAsP, forming a P-InP transition layer or an InGaAsP transition layer. Further, in some embodiments of the application, the transition layer 6035 includes a first P-InP transition layer and a first P-InGaAsP transition layer, the first P-InP transition layer and the first P-InGaAsP transition layer are sequentially grown on the upper waveguide layer 6034, such as the first P-InP transition layer and the first P-InGaAsP transition layer are sequentially grown on the upper waveguide layer 6034.

[0080] In some embodiments of the present application, a protective layer 6036 of a certain thickness is grown above the transition layer 6035, a grating layer 6037 is grown on the protective layer 6036, and then the protective layer 6036 is continuously grown on the grating layer 6037. Optionally, the protective layer 6036 is formed of InP material, i.e. a P-InP protective layer, and the grating layer 6037 is formed of AlGaInAs material, i.e. a P-AlGaInAs grating layer. In some embodiments of the present application, the length ratio of the grating layer 6037 to the AlGaInAs multiple quantum well active layer 6033 is 0.3-1, i.e. the length ratio of the grating layer 6037 to the AlGaInAs multiple quantum well active layer 6033 is 0.3-1, such as the length ratio of the grating layer 6037 to the AlGaInAs multiple quantum well active layer 6033 is 0.5.

[0081] Figure 10 A structure schematic diagram of forming a ridge waveguide layer on an active region is provided for some embodiments of the present application. As shown in the diagram, Figure 10 In some embodiments of the present application, the forming process of the ridge waveguide layer is as follows: a P-InP buffer layer is epitaxially grown above the active region 603 by MOCVD technology, a specially designed layer 6041 of InGaAsP is grown above the P-InP buffer layer, and a contact layer 6042 of P-InP and P-InGaAsP is grown above the specially designed layer 6041.

[0082] In some embodiments of the present application, the ridge waveguide 604 is formed by etching the ridge waveguide layer. Figure 11 A structure schematic diagram of etching to form a ridge waveguide is provided for some embodiments of the present application, Figure 11 The diagram shows that the ridge waveguide layer is etched to form the ridge waveguide 604.

[0083] In some embodiments of the present application, a dielectric film is formed on the ridge waveguide layer in the process of etching the ridge waveguide layer to form the ridge waveguide 604, a photoetching technology is used to make a mask required for etching the ridge waveguide, the ridge waveguide 604 with a required pattern is etched, the etching depth reaches the specially designed layer 6041 but does not reach the active region 603. The width of the ridge waveguide 604 is 1-3 μm, and optionally, the width of the ridge waveguide 604 is 1 μm, 2 μm, 2.5 μm, etc. In some embodiments of the present application, the photoetching process must be strictly controlled in the processes of glue coating, baking, exposure, and development to obtain a photoresist pattern with smooth and clear boundaries; the dielectric film can be a silicon dioxide dielectric film, and the silicon dioxide mainly functions as a mask during etching of the ridge waveguide, and can also be silicon nitride or silicon oxynitride, etc.

[0084] In some embodiments of the present application, a buried layer 605 is grown on both sides of the ridge waveguide 604. Figure 12 A structure schematic diagram of forming a buried layer on both sides of the ridge waveguide is provided for some embodiments of the present application,Figure 12 Buried layer 605 is formed on both sides of ridge waveguide 604. Optionally, buried layer 605 is a Fe-doped InP buried layer.

[0085] In some embodiments of the present application, P electrode 606 is formed on buried layer 605 and ridge waveguide 604. P electrode 606 can be formed of titanium, platinum, gold or other materials.

[0086] In some embodiments of the present application, N electrode 602 is formed on the first surface of substrate 601. N electrode 602 can be formed of gold, germanium, nickel or other materials. In some embodiments of the present application, substrate 601 is thinned from the first surface of substrate 601, and then N electrode 602 is formed on the first surface of substrate 601.

[0087] Finally, it should be noted that the embodiments are described in a progressive manner, and different parts can be referred to each other; in addition, the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A laser, characterized in that: For optical modules, including: substrate; An N electrode is provided on the first surface of the substrate; An active region is provided on a second surface of the substrate, wherein the second surface is opposite to the first surface; a ridge waveguide disposed above the active region; a buried layer, disposed on both sides of the ridge waveguide and above the active region; A P electrode is provided above the ridge waveguide and the buried layer; Wherein, the ridge waveguide comprises: A P-InP buffer layer is provided above the active area; An InGaAsP layer is provided above the P-InP buffer layer, and the InGaAsP layer is used to change the light field distribution; A P-InP contact layer, located above the InGaAsP layer; The P-InGaAsP contact layer is located above the P-InP contact layer.

2. The laser according to claim 1, characterized in that The active region includes: a buffer layer, disposed above the substrate; a lower waveguide layer, disposed above the buffer layer; an AlGaInAs MQW active layer, disposed above the lower waveguide layer; an upper waveguide layer, disposed above the AlGaInAs MQW active layer; a transition layer, disposed above the upper waveguide layer; A protective layer, disposed above the transition layer; The grating layer is arranged in the protective layer.

3. The laser according to claim 2, characterized in that The strain-compensated active region well number of the AlGaInAs multi-quantum well active layer is 3-10, the AlGaAs well band gap wavelength is 1.25μm-1.36μm, the well thickness is 5nm-10nm, the compressive strain is 0.5%-1.2%, the AlGaAs barrier band gap wavelength is 1.1μm, the barrier thickness is 5-10nm, and the tensile strain is 0.2%-0.6%.

4. The laser according to claim 1, characterized in that The N electrode is a gold, germanium or nickel N electrode, and the P electrode is a titanium, platinum or gold P electrode.

5. The laser according to claim 2, characterized in that The lower waveguide layer is an AlGaInAs lower waveguide layer with a gradient bandgap width and refractive index; The refractive index and the band gap width of the lower waveguide layer change linearly, and the closer to the AlGaInAs MQW active layer, the larger the refractive index and the narrower the band gap width; And / or, the upper waveguide layer is an AlGaInAs upper waveguide layer with a graded bandgap width and refractive index; The refractive index and the band gap width of the upper waveguide layer change linearly, and the closer to the AlGaInAs MQW active layer, the larger the refractive index and the narrower the band gap width.

6. The laser according to claim 1, characterized in that The width of the ridge waveguide is 1 μm-3 μm; the buried layer is an Fe-doped InP buried layer.

7. The laser according to claim 2, characterized in that The buffer layer is an epitaxially grown N-InP buffer layer, the protective layer is a P-InP protective layer, and the grating layer is a P-AlGaInAs grating layer.

8. The laser according to claim 2, characterized in that The transition layer includes a first P-InP transition layer and a first P-InGaAsP transition layer, and the first P-InP transition layer and the first P-InGaAsP transition layer are sequentially arranged above the upper waveguide layer.

9. A method for preparing a laser, characterized in that: For preparing the laser according to claim 1, the method comprises: forming an active region on the second surface of the substrate; A P-InP buffer layer, an InGaAsP layer, a P-InP contact layer and a P-InGaAsP contact layer are sequentially arranged on the active area; the InGaAsP layer is located above the P-InP buffer layer, the P-InP contact layer is located above the InGaAsP layer, and the P-InGaAsP contact layer is located above the P-InP contact layer; Etching the P-InGaAsP contact layer, the P-InP contact layer, the InGaAsP layer to the P-InP buffer layer but not to the active region using a mask to form a ridge waveguide; growing buried layers on both sides of the ridge waveguide; Disposing a P electrode above the buried layer and the P-InGaAsP contact layer; An N electrode is provided on the first surface of the substrate.

10. An optical module, characterized in that: include: circuit boards; a light emitting component, electrically connected to the circuit board, for generating and outputting signal light, including a laser; Wherein, the laser includes the laser according to claim 1 or the laser prepared by the preparation method according to claim 9.

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