An optical module

Abstract

The present application provides an optical module. By using a substrate as the optical platform for carrying components, a gasket is provided on its upper surface. The gasket includes an insulating and heat-conducting layer, a grounding metal layer disposed on the upper surface of the insulating and heat-conducting layer, and high-speed signal lines. The cathode of the laser chip is fixed on the above-mentioned grounding metal layer, and the anode is electrically connected to the high-speed signal lines through wire bonding. In addition, the high-speed signal lines of the gasket are connected to the circuit board through wire bonding. In this way, the electrical signals from the circuit board can be transmitted to the optical receiving chip to achieve the optical emission function of the optical module. At the same time, the lower surface of the end of the circuit board is also fixed on the substrate, which can also ensure the stability of the relative position between the gasket and the circuit board and the performance stability of the components. Therefore, using the substrate to replace the existing housing has a simple structure, effectively reduces the material cost of the optical emission sub-optical mode, and since the substrate has an open structure, the problem of difficult packaging due to small space can be solved.

Description

Technical Field

[0001] This application relates to the field of optical communication technologies, and in particular, to an optical module. Background Art

[0002] In new services and application models such as cloud computing, mobile Internet, and video, optical communication technologies are used. An optical module realizes the function of optoelectronic conversion in the field of optical communication technologies and is one of the key components in optical communication devices.

[0003] Generally, an optical emission part is provided in the optical module for emitting optical signals. To fix the related components for optical emission, the optical emission part usually includes a cover plate and a cavity. During module packaging, first, components such as a semiconductor cooler, an optical emission chip, and a lens are fixed in the cavity. In addition, a circuit board or a flexible board is inserted into the cavity through an opening on one side wall of the cavity to achieve electrical connection between the circuit board and the optical emission chip. Then, the cover plate covers the cavity from above, and the two are fixed together by resistance welding or using glue.

[0004] However, with the increase in the communication rate of the optical module, more and more devices need to be arranged in the cavity of the optical emission part. Currently, the optical module is becoming smaller and smaller, and the smaller the external dimensions of the device are required to be, the better. Therefore, the space in the cavity of the optical emission part is very small, which is not convenient for production operations. Summary of the Invention

[0005] Aiming at the problems of complex housing structure and high packaging process difficulty in the existing optical emission part, this embodiment provides an optical module.

[0006] The optical module provided in this embodiment mainly includes:

[0007] An upper housing and a lower housing;

[0008] A circuit board disposed between the upper housing and the lower housing;

[0009] A substrate, whose lower surface is in contact with the lower housing, and the lower surface of the end of the circuit board is disposed on the upper surface of the end of the substrate;

[0010] A gasket disposed on the upper surface of the substrate, including an insulating and heat-conducting layer, a grounding metal layer disposed on the upper surface of the insulating and heat-conducting layer, and high-speed signal lines; the ends of the high-speed signal lines are electrically connected to the circuit board by wire bonding for transmitting electrical signals from the circuit board to the laser chip;

[0011] The laser chip, whose cathode is fixed on the grounding metal layer and whose anode is electrically connected to the high-speed signal lines by wire bonding, is used for emitting optical signals based on the electrical signals.

[0012] As can be seen from the above embodiments, in this embodiment, the substrate is used as the optical platform for carrying the device, and a gasket is arranged on its upper surface. Among them, the gasket includes an insulating and heat-conducting layer, a grounding metal layer disposed on the upper surface of the insulating and heat-conducting layer, and high-speed signal lines. The cathode of the laser chip is fixed on the above-mentioned grounding metal layer, and the anode is electrically connected to the high-speed signal lines through wire bonding. In addition, the high-speed signal lines of the gasket are connected to the circuit board through wire bonding. In this way, the electrical signals from the circuit board can be transmitted to the optical receiving chip, realizing the optical emission function of the optical module. At the same time, the lower surface of the end of the circuit board is also fixed on the substrate, which can also ensure the stability of the relative position between the gasket and the circuit board, and ensure the performance stability of the device. Therefore, using the substrate to replace the existing housing has a simple structure, effectively reducing the material cost of the optical emission secondary optical mode. Moreover, the structure on the substrate is an open structure, which can thus solve the problem of difficult packaging due to small space. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0014] Figure 1 Schematic diagram of the connection relationship of the optical communication terminal;

[0015] Figure 2 Schematic diagram of the structure of the optical network unit;

[0016] Figure 3 Schematic diagram of the structure of an optical module provided in an embodiment of the present application;

[0017] Figure 4 Exploded structure diagram of an optical module provided in an embodiment of the present application;

[0018] Figure 5 Schematic diagram of the structure of the optical emission part and the circuit board provided in an embodiment of the present application;

[0019] Figure 6 Exploded structure diagram of the optical emission part and the circuit board provided in an embodiment of the present application;

[0020] Figure 7 Exploded structure diagram of the optical emission part provided in an embodiment of the present application;

[0021] Figure 8 Assembly structure diagram of the optical emission part provided in an embodiment of the present application;

[0022] Figure 9 For Figure 8 Partial enlarged view of area A in

[0023] Figure 10 Exploded structural schematic diagram of the wire bonding protection component and the circuit board provided by the embodiment of the present application;

[0024] Figure 11 Structural schematic diagram of the wire bonding protection component provided by the embodiment of the present application;

[0025] Figure 12 Top view of the circuit board and the optical emission part provided by the embodiment of the present application;

[0026] Figure 13 Side view of the circuit board and the optical emission part provided by the embodiment of the present application;

[0027] Figure 14 Is Figure 13 Enlarged view of part B in

[0028] Figure 15 Structural schematic diagram of the substrate provided by the embodiment of the present application;

[0029] Figure 16 Top view of the optical emission part provided by this embodiment;

[0030] Figure 17 First split structural schematic diagram of the isolator, the antireflection film and the fiber optic adapter provided by the embodiment of the present application;

[0031] Figure 18 Second split structural schematic diagram of the isolator, the antireflection film and the fiber optic adapter provided by the embodiment of the present application;

[0032] Figure 19 First structural schematic diagram of the focusing lens and the fiber optic adapter provided by the embodiment of the present application;

[0033] Figure 20 Second structural schematic diagram of the focusing lens and the fiber optic adapter provided by the embodiment of the present application;

[0034] Figure 21A Optical path structure schematic diagram of an optical emission part provided by the prior art;

[0035] Figure 21B Is Figure 21A Optical path structure coupling efficiency simulation diagram in

[0036] Figure 22A Optical path structure schematic diagram of an optical emission part provided by the existing technology;

[0037] Figure 22B Is Figure 22A Optical path structure coupling efficiency simulation diagram in

[0038] Figure 23It is a simulation diagram of the coupling efficiency when the optical axis enters the inclined fiber ferrule through the center of the second lens;

[0039] Figure 24A It is a schematic diagram of the optical path structure of the optical emission part provided by the embodiment of the present application;

[0040] Figure 24B It is Figure 24A the simulation diagram of the coupling efficiency of the optical path structure in Specific Embodiments

[0041] Next, the technical solutions in the embodiments will be clearly and completely described in conjunction with the accompanying drawings in the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0042] One of the core links in optical fiber communication is the conversion between optical and electrical signals. Optical fiber communication uses optical signals carrying information to transmit in optical fibers / optical waveguides. The passive transmission characteristics of light in optical fibers can be used to achieve low-cost and low-loss information transmission. However, information processing devices such as computers use electrical signals, so it is necessary to realize the mutual conversion between electrical signals and optical signals during the signal transmission process.

[0043] The optical module realizes the above-mentioned optoelectronic conversion function in the field of optical fiber communication technology. The mutual conversion between optical signals and electrical signals is the core function of the optical module. The optical module realizes the electrical connection with the external host computer through the gold fingers on the circuit board. The main electrical connections include power supply, I2C signal, transmission data signal, and grounding, etc. The electrical connection method realized by the gold fingers has become the standard method in the optical module industry. Based on this, the circuit board is an essential technical feature in most optical modules.

[0044] Figure 1 It is a schematic diagram of the connection relationship of the optical communication terminal. As Figure 1 shown, the connection of the optical communication terminal mainly includes the optical network unit 100, the optical module 200, the optical fiber 101, and the network cable 103;

[0045] One end of the optical fiber is connected to the remote server, and one end of the network cable is connected to the local information processing device. The connection between the local information processing device and the remote server is completed by the connection of the optical fiber and the network cable; while the connection between the optical fiber and the network cable is completed by the optical network unit with an optical module.

[0046] The optical port of the optical module 200 is connected to the optical fiber 101, establishing a two-way optical signal connection with the optical fiber; the electrical port of the optical module 200 is connected to the optical network unit 100, establishing a two-way electrical signal connection with the optical network unit; the optical module realizes the mutual conversion between optical signals and electrical signals, thereby establishing a connection between the optical fiber and the optical network unit; 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 unit 100, and the electrical signal from the optical network unit 100 is converted into an optical signal by the optical module and input into the optical fiber. The optical module 200 is a tool for realizing the mutual conversion between optical and electrical signals and does not have the function of processing data. During the above optical-electrical conversion process, the information does not change.

[0047] The optical network unit has an optical module interface 102 for connecting to the optical module and establishing a two-way electrical signal connection with the optical module; the optical network unit has a network cable interface 104 for connecting to the network cable and establishing a two-way electrical signal connection with the network cable; a connection is established between the optical module and the network cable through the optical network unit. Specifically, the optical network unit transmits the signal from the optical module to the network cable and transmits the signal from the network cable to the optical module. The optical network unit monitors the operation of the optical module as the host computer of the optical module.

[0048] Thus, the remote server establishes a two-way signal transmission channel with the local information processing device through the optical fiber, optical module, optical network unit, and network cable.

[0049] Common information processing devices include routers, switches, electronic computers, etc.; the optical network unit is the host computer of the optical module, providing data signals to the optical module and receiving data signals from the optical module. Other common host computers of the optical module include optical line terminals, etc.

[0050] Figure 2 It is a schematic diagram of the structure of the optical network unit. As Figure 2 shown, there is a circuit board 105 in the optical network unit 100, and a cage 106 is arranged on the surface of the circuit board 105; an electrical connector is arranged in the cage 106 for connecting to the electrical port of the optical module such as the gold finger; a heat sink 107 is arranged on the cage 106, and the heat sink 107 has a raised structure such as fins for increasing the heat dissipation area.

[0051] The optical module 200 is inserted into the optical network unit. Specifically, the electrical port of the optical module is inserted into the electrical connector in the cage 106, and the optical port of the optical module is connected to the optical fiber 101.

[0052] The cage 106 is located on the circuit board, wrapping the electrical connector on the circuit board in the cage; the optical module is inserted into the cage, and the cage fixes the optical module. The heat generated by the optical module is conducted to the cage through the housing of the optical module and finally dissipated through the heat sink 107 on the cage.

[0053] Figure 3Schematic diagram of the structure of an optical module 200 provided by an embodiment of the present application. Figure 4 Schematic exploded view of the optical module 200 provided by this embodiment. As Figure 3 and Figure 4 shown, the optical module 200 provided by the embodiment of the present application includes an upper housing 201, a lower housing 202, an unlocking handle 203, a circuit board 30, an optical transmitting part 40, and an optical receiving part 50.

[0054] The upper housing 201 covers the lower housing 202 to form a wrapped cavity with two openings; the outer contour of the wrapped cavity generally presents a square body. Specifically, the lower housing includes a main board and two side boards located on both sides of the main board and perpendicular to the main board; the upper housing includes a cover plate, and the cover plate covers the two side boards of the upper housing to form the wrapped cavity; the upper housing may further 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 boards to realize the upper housing covering the lower housing.

[0055] The two openings may specifically be two openings at both ends in the same direction (204, 205), or two openings in different directions; one of the openings is an electrical port 204, and the gold fingers of the circuit board extend out from the electrical port 204 and are inserted into a host computer such as an optical network unit; the other opening is an optical port 205, which is used for external optical fiber access to connect the optical transmitting part 40 and the optical receiving part 50 inside the optical module; optoelectronic devices such as the circuit board 30, the optical transmitting part 40, and the optical receiving part 50 are located in the wrapped cavity.

[0056] Adopting the assembly method of combining the upper housing and the lower housing facilitates the installation of devices such as the circuit board 30, the optical transmitting part 40, and the optical receiving part 50 into the housing, and the upper housing and the lower housing form the outermost packaging and protection housing of the optical module; the upper housing and the lower housing generally adopt metal materials, which is beneficial to realizing electromagnetic shielding and heat dissipation; generally, the housing of the optical module is not made into an integral structure, because in this way, positioning components, heat dissipation, and electromagnetic shielding structures cannot be installed during the assembly of devices such as the circuit board, and it is not conducive to production automation.

[0057] The unlocking handle 203 is located on the outer wall of the wrapped cavity / lower housing 202 and is used to realize the fixed connection between the optical module and the host computer, or to release the fixed connection between the optical module and the host computer.

[0058] The unlocking handle 203 has a latching structure that matches the upper computer cage; pulling the end of the unlocking handle can cause the unlocking handle to move relative to the surface of the outer wall; the optical module is inserted into the cage of the upper computer, and the optical module is fixed in the cage of the upper computer by the latching structure of the unlocking handle; by pulling the unlocking handle, the latching structure of the unlocking handle moves accordingly, thereby changing the connection relationship between the latching structure and the upper computer to release the latching relationship between the optical module and the upper computer, so that the optical module can be withdrawn from the cage of the upper computer.

[0059] On the circuit board 30, there are circuit traces, electronic components (such as capacitors, resistors, triodes, MOS transistors), and chips (such as microprocessor MCU2045, laser driver chip, limiting amplifier, clock data recovery CDR, power management chip, data processing chip DSP), etc.

[0060] The circuit board 30 connects the electrical devices in the optical module together according to the circuit design through the circuit traces to achieve electrical functions such as power supply, electrical signal transmission, and grounding.

[0061] The circuit board 30 is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also achieve a bearing function. For example, the rigid circuit board can stably carry the chip; the rigid circuit board can also be inserted into the electrical connector in the cage of the upper computer. Specifically, metal pins / gold fingers are formed on the surface of one end of the rigid circuit board for connection with the electrical connector; these are not easily achieved by flexible circuit boards.

[0062] Flexible circuit boards are also used in some optical modules as a supplement to rigid circuit boards; flexible circuit boards are generally used in cooperation with rigid circuit boards. For example, a flexible circuit board can be used to connect the rigid circuit board and the optical transceiver device.

[0063] The optical module also includes an optical emission part and an optical reception sub-module, and the optical emission part and the optical reception sub-module can be collectively referred to as an optical sub-module. As Figure 4 shown, the optical module provided by the embodiment of the present invention includes an optical emission part 40 and an optical reception part 50. Among them, the optical emission part 40 is used to convert an electrical signal into an optical signal, and the generated optical signal is transmitted to the outside of the optical module through the optical fiber socket 60; the optical reception part 50 is used to convert the optical signal received through the optical fiber socket 60 into an electrical signal. In this embodiment, the optical reception part 50 is arranged on the surface of the circuit board 30. In another common packaging method, the optical reception sub-module is physically separated from the circuit board and electrically connected through a flexible board.

[0064] For some optical module usage environments, the conditions are relatively good. For example, in a data center, there is air conditioning to control the temperature and humidity. Therefore, the requirement for the device's sealing performance is not high, but the requirement for the finished product cost is higher. Additionally, for the optical emission part, a package method using a housing is adopted. The housing usually uses machining or a molded housing, so the housing design is relatively complex and the production cost is high. Moreover, when packaging the module, components such as a thermoelectric cooler, an optical emission chip, and a lens need to be fixed inside the housing, and the internal space of the cavity in the optical emission part is very small, which is inconvenient for production operations. Figure 5 The structural schematic diagram of the optical emission part and the circuit board provided by the embodiment of the present application Figure 6 The exploded structural schematic diagram of the optical emission part and the circuit board provided by the embodiment of the present application. As Figure 5 and 6 shown, in this embodiment, the optical emission part 40 is packaged in a non-hermetic manner, physically separated from the circuit board 30, and electrically connected through wire bonding of a metal material, such as electrically connected through gold wires. Among them, for the optical emission part 40, in this embodiment, a substrate is used as the optical platform, and devices such as a laser chip and a thermoelectric cooler are placed on the substrate for the packaging method.

[0065] It should be noted that the optical emission part 40 in this embodiment includes 4 optical paths with the same wavelength, and the data transmission rate is increased by increasing the number of optical paths. In other embodiments, it can also be set to other numbers. Additionally, the following embodiments illustrate the solution of the present implementation by taking one of the optical paths as an example.

[0066] Figure 7 The exploded structural schematic diagram of the optical emission part provided by the embodiment of the present application Figure 8 The assembled structural schematic diagram of the optical emission part provided by the embodiment of the present application. As Figure 7 and 8 shown, to reduce the production cost and provide a flat bearing surface for devices such as a laser chip and a thermoelectric cooler, the optical emission part 40 in this embodiment includes a substrate 41 as the optical platform, and devices such as a TEC (Thermoelectric cooler) 42, a gasket 43, a laser chip 44, a collimating lens 45, an isolator 46, an anti-reflection film (AR film) 47, and an optical fiber adapter 48 are arranged on the upper surface of the substrate 41.

[0067] To facilitate the heat dissipation of each component disposed on the upper surface of the substrate 41, the lower surface of the substrate 41 can be fixed to the housing of the optical module, such as the lower housing 201, through a heat-conducting adhesive. In this way, the heat generated by the components in the optical emission part 40 can be conducted through the substrate 41 to the housing of the optical module, and then conducted to the outside of the optical module through the housing of the optical module. Further, considering factors such as heat dissipation effect, processing accuracy, and thermal expansion, in this embodiment, the substrate 41 is made of tungsten copper, that is, an alloy composed of tungsten and copper. Of course, in other embodiments, other materials can also be used, such as ceramics.

[0068] The TEC 42 is used to conduct the heat generated by the laser chip 44 out of the substrate 41. Specifically, the TEC 42 includes an upper heat exchange surface and a lower heat exchange surface. A gasket 43 is disposed on the top of the upper heat exchange surface, and the upper heat exchange surface is used to absorb the heat generated by the laser chip 44 transmitted by the gasket 43. The bottom of the upper heat exchange surface is connected to the lower heat exchange surface, and the lower heat exchange surface is fixed on the upper surface of the substrate 41. Therefore, the heat of the lower heat exchange surface of the TEC 42 can be conducted out of the optical module by using the substrate 41.

[0069] Figure 9 For Figure 8 a partial enlarged schematic view of area A in Figure 9 As shown, the gasket 43 in this embodiment includes an insulating heat-conducting layer 431 and a metallized circuit pattern (also known as a trace). The insulating heat-conducting layer 431 can be made of a ceramic material with good heat conduction performance, good insulation performance, and high processing accuracy. Of course, it is not limited to ceramics. Among them, in order to facilitate the installation of each electrical component on the gasket 43, in this embodiment, the metallized circuit pattern disposed on the upper surface of the insulating heat-conducting layer 431 includes a high-speed signal line 432 and a ground line 433. The lower surface of the insulating heat-conducting layer 431 is in contact with the upper surface of the TEC 42. The cathode of the laser chip 44 can be fixed on the ground line 433 of the gasket 43 by welding or conductive glue, etc., and the anode of the laser chip 44 can be connected to the high-speed signal line 432 by wire bonding.

[0070] It should be noted that the design shapes and layouts of the high-speed signal line 432 and the ground line 433 are not limited to the manner provided in this embodiment. In other embodiments, they can be designed according to requirements such as the signal transmission rate and the components to be arranged.

[0071] During the operation of the optical module, high-frequency data electrical signals from the host computer are transmitted to chips such as a clock data recovery chip and a laser driver chip arranged on the circuit board 30 through the gold fingers on the circuit board 30. The above-mentioned chips such as the clock data recovery chip and the laser driver chip perform signal shaping, amplitude adjustment and other processing on the high-frequency data electrical signals received by the optical module. In order to transmit the shaped high-frequency data electrical signals to the laser chip 44 arranged on the spacer 43 so that the laser chip emits data optical signals, and in this embodiment, ground wires and high-frequency signal lines (not shown in the figure) are also arranged on the circuit board 30. At the same time, the high-frequency signal lines on the circuit board 30 are connected to the high-speed signal lines 432 on the spacer 43 by wire bonding, and the ground wires on the circuit board 30 are connected to the ground wires 433 on the spacer 43 through wire bonding pads, so that the electrical signals from the circuit board 30 can be transmitted to the laser chip 44. It should be noted that components such as backlight detectors, resistors, and capacitors can also be arranged on the spacer 43, and each component can be electrically connected to the circuit board 30 through corresponding traces arranged on the spacer 45 to achieve stable light emission of the laser chip 44.

[0072] Figure 10 This is a schematic exploded view of the wire bonding protection component and the circuit board provided by the embodiment of the present application. As Figure 10 shown, in this embodiment, since the diameter of the wire bonding between the circuit board 30 and the spacer 43 is usually relatively thin, in order to prevent the wire bonding from being disconnected due to the relative movement of the circuit board 30 and the spacer 43, and considering impedance matching and other issues, there are also requirements for the length of the wire bonding connecting the high-frequency signal lines on the circuit board 30 and the spacer 43. Therefore, in order to ensure the stability of the relative position of the circuit board 30 and the spacer 43, in this embodiment, the lower surface of the end of the circuit board 30 close to the substrate 41 is fixed on the upper surface of the substrate 41.

[0073] Figure 11 This is a schematic structural view of the wire bonding protection component provided by the embodiment of the present application. As Figure 10 and 11 shown, in order to avoid the wire bonding connecting the circuit board 30 and the spacer 43 from being touched, in this embodiment, a wire bonding protection component 70 is arranged on the circuit board 30. In order to prevent the wire bonding protection component 70 from conducting electricity, it can be made of a non-metallic material, for example, made of a plastic material, and is fixed on the circuit board 30 with a non-conductive glue. The wire bonding used to connect the spacer 43 and the circuit board 30 is covered under the wire bonding protection component 70, so as to avoid problems such as the wire bonding being touched and causing collapse or damage.

[0074] Furthermore, for the convenience of heat dissipation of the devices located under the wire bonding protection component 70 and to reduce the floor area of the wire bonding protection component 70 on the circuit board, as Figure 11As shown, in this embodiment, the wire bonding protection component 70 is set to be composed of a protection plate 71 and two or more support members 72. Among them, the protection plate 71 is a flat plate structure, and its specific shape can be set according to the layout requirements of the circuit board 30. For example, in this embodiment, it is designed as an L-shaped structure. One end of the support member 72 is fixedly connected to the lower surface of the protection plate 71, and the other end is non-conductively fixed to the upper surface of the circuit board 30 through glue or the like.

[0075] Figure 12 This is a top view of the circuit board and the optical emission part provided by the embodiment of the present application. As Figure 12 shown, since the laser chip 44 and the spacer 43 are also wire-bonded, in this embodiment, in addition to arranging the wire bonding connecting the circuit board 30 and the spacer 43 under the protection plate 71 in the wire bonding protection component 70, the spacer 43 is also arranged under the protection plate 71 in the wire bonding protection component 70. In addition, signals such as high-frequency data signals and bias signals received by the laser chip 44 need to be processed by a laser driver chip (not shown in the figure) arranged on the circuit board 30 and then sent to the laser chip 44. Usually, the laser driver chip is also electrically connected to the circuit board 30 through wire bonding. Therefore, in this embodiment, the driver chip is also arranged close to the spacer 43 and is arranged under the wire bonding protection component 70.

[0076] Therefore, in this embodiment, the substrate 41 is used to replace the existing housing of the optical emission part, with a simple structure, effectively reducing the material cost of the secondary optical mode of the optical emission, and the upper part of the substrate 41 is an open structure, thereby solving the problem of difficult packaging due to the small space inside the housing. In addition, by setting the assembly method between the substrate 41 and the circuit board 30 and setting the wire bonding protection component 70, the use performance of the module can be effectively guaranteed.

[0077] Figure 13 This is a top view of the circuit board and the optical emission part provided by the embodiment of the present application, Figure 14 is Figure 13 an enlarged view of part B in Figure 13 and 14 shown. Since the light emitted by the laser chip 44 is divergent light and the light incident aperture of the optical fiber is generally small, in order to improve the optical coupling efficiency, in this embodiment, the incident surface of the focusing lens 45 is arranged facing the light-emitting surface of the laser chip 44, and the light-emitting surface of the focusing lens 45 is arranged facing the incident surface of the fiber optic adapter 48. The focusing lens 45 is used to couple the divergent light emitted by the laser chip 44 into the optical fiber in the fiber optic adapter 48. Since the light incident aperture of the optical fiber is generally small, in order to ensure the optical coupling efficiency, in this embodiment, by adjusting the position of the focusing lens 45, the focal point of the focusing lens 45 is located near the end face of the optical fiber in the fiber optic ferrule 803.

[0078] In addition, in order to make the light converge after passing through the focusing lens 45, but the optical axis direction does not change before and after convergence, that is, the light enters along the center of the focusing lens. This incident direction can ensure to the greatest extent that the light after convergence retains the mode spot distribution before convergence, presenting a regular circular light spot, which is conducive to improving the efficiency in the subsequent coupling process. Therefore, in this embodiment, the light emitted by the laser chip 44 can be set to enter along the center of the focusing lens 45, specifically referring to the light converging through the center of the focusing lens. In an ideal state, the center of the light beam emitted by the laser chip 44 passes through the optical axis of the focusing lens 45. Therefore, in order to achieve the alignment between the laser chip 44 and the focusing lens 45, and in combination with the existing lens and laser chip size characteristics, the focusing lens 45 is arranged on the upper surface of the TEC 42 in this embodiment, that is, the spacer 43 is used to make up for the height difference between the laser chip 44 and the focusing lens 45.

[0079] Since the light incident aperture of the optical fiber is generally small, the stability of the relative position between the focusing lens 45 and the fiber adapter 48 is also very important. For the above reasons, the fiber adapter 48 is also fixed on the upper surface of the substrate 41 in this embodiment. In order to make more light emitted by the focusing lens 45 enter the optical fiber of the fiber dispenser 48, in an ideal state, the optical axes of the focusing lens 45 and the fiber dispenser 48 should be on the same horizontal plane or approximately on the same horizontal plane.

[0080] Figure 15 It is a schematic structural diagram of the substrate provided by the embodiment of the present application. As Figure 15 shown, in order to achieve the alignment between the focusing lens 45 and the fiber dispenser 48, the substrate 41 is also designed in this embodiment. Among them, a recess 412 is provided in the middle area of the substrate 41. In this way, the upper surface of the substrate 41 is divided into a first upper surface 411 and a second upper surface 413 by the recess 412, and the first upper surface 411 and the second upper surface 413 are respectively located on both sides of the recess 412.

[0081] The first upper surface 411 is used for fixedly connecting with the lower surface of the end of the circuit board 30; the second upper surface 413 is used for arranging the fiber optic adapter 48; the recessed part 412 is used for arranging the semiconductor refrigerator 42. Among them, the lower surface of the semiconductor refrigerator 42 is in contact with the bottom of the recessed part, and the upper surface is provided with a gasket 43 and a focusing lens 45. The laser chip 44 is arranged on the upper surface of the gasket 43, so that the upper surface of the gasket 43 and the upper surface of the circuit board 30 are in the same horizontal plane or approximately in the same horizontal plane to facilitate wire bonding. In addition, the optical axis of the fiber optic adapter 48 and the optical axis of the focusing lens 45 can be in the same horizontal plane or approximately in the same horizontal plane to improve the optical coupling efficiency. In this embodiment, by setting the substrate 41 to have a recessed structure, not only its bearing function is realized, but also the alignment function between various devices is effectively realized. Compared with the flat substrate 41, it is more convenient for packaging and can effectively save the raw materials used for adjusting the device height.

[0082] As Figure 14 shown, in order to isolate the reflected light in the optical path, an isolator 46 is usually further arranged on the light output side in this embodiment. Based on the characteristic that the light emitted by the laser chip 44 is divergent light, in this embodiment, the isolator 46 is arranged on the light output side of the focusing lens 45. In addition, due to reasons such as the small available space on the TEC 42, in this embodiment, the isolator 46 is arranged on the second upper surface 413 of the substrate 41.

[0083] The isolator 46 in this embodiment is based on the principle of light polarization and only allows light to pass through in a single direction. Based on the working principle of the isolator 46, by adjusting the angle between the polarization direction of the laser emitted by the laser chip and the polarization direction of the isolator 46, the coupling power between the laser chip 44 and the isolator 46 is adjusted, and thus the output optical power of the optical module can be controlled.

[0084] In addition, for high-speed optical modules, for example, 400G products, they have higher requirements for the optical power coupling efficiency. When light enters the optical fiber from the air, about 4% of the light is emitted, which causes a loss of coupling efficiency. Therefore, in this embodiment, an antireflection film 47 is further arranged between the isolator 46 and the fiber optic adapter 48, and thus the end face emission at the fiber optic adapter 48 can be effectively reduced.

[0085] Figure 16 This is the top view of the light emission part provided in this embodiment. As Figure 16As shown, in order to reduce the light reflected by the isolator 46 from returning to the laser chip 44 and reduce the return loss, in this embodiment, an included angle θ is provided between the normal line of the light incident surface of the isolator 46 (or the normal line of the light incident surface) and the optical axis of the focusing lens 45. The value of this included angle can be set as needed. For example, it can be set to 5°, 10°, etc. It should be noted that in this embodiment, the optical axis of the light beam emitted by the laser chip 44 (or the light output direction of the laser chip 44) coincides or approximately coincides with the optical axis of the focusing lens 45. In other embodiments, the two may not coincide. Furthermore, if there is an included angle θ between the normal line of the light incident surface of the isolator 46 and the optical axis of the focusing lens 45, then the included angle θ is between the normal line of the light incident surface of the isolator 46 and the optical axis of the light beam emitted by the laser chip 44.

[0086] In this way, the light emitted by the laser chip 44 passes through the focusing lens 45, the isolator 46, and the antireflection film 47 in sequence, and then enters the optical fiber in the fiber optic adapter 48 through the air. Among them, if the optical fiber is vertically incident on the end face of the optical fiber, this method is easy to control the angular relationship between the light output direction of the laser chip and the ferrule of the optical fiber. However, vertical incidence will cause the reflected light to return along the original optical path, and the returned light will return to the laser chip 44, which will affect the light output of the laser chip 44.

[0087] Therefore, in order to prevent the reflected light from returning along the original optical path, the optical path is designed so that the light is not vertically incident on the end face of the optical fiber. In order to achieve non-vertical incidence of the light on the end face of the optical fiber, in this embodiment, the light incident surface of the fiber optic adapter 48 is set as an inclined surface.

[0088] Figure 17 It is the first split structure schematic diagram of the isolator, antireflection film and fiber optic adapter provided by the embodiment of the present application. Figure 18 It is the second split structure schematic diagram of the isolator, antireflection film and fiber optic adapter provided by the embodiment of the present application. As Figure 17 As shown in and shown in 18, based on the design that the normal line of the light incident surface of the isolator 46 and the optical axis of the focusing lens 45 have an included angle, and the light incident surface of the fiber optic adapter 48 also has a certain inclination angle, and in order to facilitate fixing the isolator 46, antireflection film 47 and fiber optic adapter 48 on the substrate 41, in this embodiment, the three are fixed together by means of glue, silver glue, etc. Among them, the antireflection film 47 can be fixed on the light incident end face of the fiber optic adapter 48, and then the isolator 46 is fixed on the antireflection film 47. When module packaging, the spacer 43, laser chip 44 and focusing lens 45 can be mounted in a passive manner, and then the optical component composed of the isolator 46, antireflection film 47 and fiber optic adapter 48 is actively coupled.

[0089] As Figure 18As shown, by setting the end face of the fiber optic adapter 48 to have a first inclination angle θ1, where this inclination angle is equal to the angle between the normal line of the end face of the fiber optic adapter 48 and the optical axis of the focusing lens 45. Further, after the isolator 46 and the fiber optic adapter 48 are mounted together, the normal line of the light incident surface of the isolator 46 and the optical axis of the focusing lens 45 also have the first inclination angle θ1. Additionally, as Figure 18 shown, in this embodiment, the port 482 for inserting the optical fiber in the fiber optic adapter 48 is set to a conical structure. During encapsulation, it is inserted into the fiber optic adapter 48 through this port 482, and then glue is poured into the conical port 482, thus facilitating the fixation of the optical fiber.

[0090] In this embodiment, an optical fiber ferrule can be provided in the fiber optic adapter 48. The optical fiber ferrule is composed of a ceramic cylinder wrapping the optical fiber. The central axis of the optical fiber ferrule is the same as the central axis of the optical fiber. The light incident surface of the optical fiber ferrule is ground into an inclined surface, that is, the light incident surface of the optical fiber is ground into the same inclined surface. Further, the optical fiber is composed of a core layer and a cladding layer with different refractive indices, and total internal reflection occurs at the interface between the core layer and the cladding layer, thereby being constrained to transmit in the core layer.

[0091] The prerequisite for total internal reflection to occur is to have a large enough incident angle. Therefore, for total internal reflection to occur when light is in the optical fiber, it is required that after refraction occurs at the light incident surface of the optical fiber, the refraction angle is small enough to satisfy that there is a large enough incident angle when the light is reflected again inside the optical fiber. And to form a small enough refraction angle after refraction, a small enough incident angle is required during refraction; to achieve better coupling efficiency, it is required that the optical axis after the light enters the optical fiber is parallel to the central axis of the optical fiber, and the light beam entering the optical fiber is axisymmetric about the center. Thus, the light incident on the light incident surface of the optical fiber has a specific incident angle range.

[0092] However, after the light incident surface of the fiber optic adapter 48 is set to have a certain inclination angle as described above, it will cause the light beam converged by the focusing lens 45, especially the light beam near the optical axis, to enter the light incident surface of the optical fiber in a non-perpendicular direction, increasing the incident angle and also increasing the refraction angle. Further, it is not conducive to total internal reflection occurring at the interface between the core layer and the cladding layer of the light entering the optical fiber, thereby reducing the coupling efficiency. To address the above problems, in this embodiment, the placement position of the fiber optic adapter 48 on the substrate 41 is optimized, such that within a plane parallel or approximately parallel to the upper surface of the substrate 41, the fiber optic adapter 48 is inclinedly arranged on the substrate 41, so that the central axis of the optical fiber in the fiber optic adapter 48 is not parallel to the optical axis of the focusing lens 45.

[0093] Figure 19 This is the first structural schematic diagram of the focusing lens and the fiber optic adapter provided by the embodiment of the present application. As Figure 19As shown in the figure, in this embodiment, the end face of the optical fiber adapter 48 is set to have a first inclination angle θ1. For example, it can be set to 7°, 8°, etc., but not limited to this value. At the same time, correspondingly, the light incident surface of the internal optical fiber (not shown in the figure) of the optical fiber adapter 48 also has the first inclination angle θ1. Then, along the inclination direction of the end face of the optical fiber adapter 48, the central axis of the optical fiber adapter 48 is set to have a second inclination angle θ2 relative to the optical axis of the focusing lens 45. For example, it can be set to 3°, 2°, etc., but not limited to this value.

[0094] In addition, since in this embodiment, the isolator 46 and the antireflection film 47 are fixed on the end face of the optical fiber adapter 48, the light incident surface of the isolator 46 can have an inclination angle θ relative to the focusing lens 45, that is, the normal line of the light incident surface of the isolator 46 and the optical axis of the focusing lens 45 have an included angle θ.

[0095] Figure 20 This is the second structural schematic diagram of the focusing lens and the optical fiber adapter provided by the embodiment of the present application. As Figure 20 shown, through the above settings, the optical axis direction of the light beam refracted into the optical fiber can be parallel or approximately parallel to the central axis of the optical fiber, thereby effectively improving the optical coupling efficiency.

[0096] Next, the solution provided by this embodiment will be compared with the existing solution. The light emitted by the laser chip 44 is centrosymmetric about the optical axis, and the light entering the optical fiber is also centrosymmetric about the optical axis. Three typical light rays are taken as examples for illustration, and the light ray at the optical axis is used for schematic explanation.

[0097] Figure 21A This is a schematic diagram of the optical path structure of a light emission part provided by the prior art. Figure 21B For Figure 21A the simulation diagram of the coupling efficiency of the optical path structure in Figure 21A As shown, in this embodiment, the focusing lens is composed of a first lens 45a and a second lens 45b. The central axis of the optical fiber adapter (not shown in the figure) is parallel to the optical axis direction of the light beam emitted by the laser chip 44. It is assumed that the central axis of the optical fiber adapter is parallel to the central axis of the optical fiber ferrule (not shown in the figure), and the central axis of the optical fiber ferrule is parallel to the central axis of the optical fiber 481 in the optical fiber ferrule (coincident in the ideal state). The divergent light emitted by the laser chip 44 is converged into parallel light by the first lens 45a, and the parallel light is converged by the second lens 45b and then enters the light incident surface of the optical fiber 481. The light after two convergences maintains the original optical axis direction, and the spot shape remains unchanged. In the ideal state, it is a circular spot. The converged light meets the angle requirements of total internal reflection of the optical fiber, and the optical axis of the converged light is perpendicular to the light incident surface of the optical fiber. As Figure 21B shown, the light is converged through the center of the focusing lens, and the converged light is coupled into the optical fiber 481. Most of the light is transmitted through the optical fiber, and there is less light distributed around the optical fiber. Figure 21AThe optical path structure achieves a high coupling efficiency.

[0098] The optical axis is perpendicular to the incident light surface. At this time, the refraction that occurs has the smallest incident angle (0°) and the smallest refraction angle. Figure 21A The adopted optical path design can meet the angular requirements of total internal reflection of the optical fiber, and the spot shape is also beneficial to optical coupling. However, the reflected light generated on the incident light surface of the optical fiber will return along the original optical path, thereby affecting the light output of the laser chip 44.

[0099] Therefore, Figure 21A and Figure 21B The advantage of this optical path design is that the center of the focusing lens is used for optical path convergence, which can maintain a good spot mode shape. The disadvantage is that the reflected light generated on the incident light surface of the optical fiber will return to the laser chip along the original optical path.

[0100] Figure 22A It is a schematic diagram of the optical path structure of the light emission part provided by the prior art. Figure 22B For Figure 22A is the simulation diagram of the coupling efficiency of the optical path structure in. It should be noted that in the plan view, the different inclination directions of the optical fiber bevel are only due to different viewing angles. The optical fiber is a cylinder, and different inclination directions of the bevel are seen when rotating the viewing angle. As Figure 22A shown, the central axis of the optical fiber 481 is parallel to the light output optical axis direction of the laser chip 44. The divergent light emitted by the laser chip 44 is converged into parallel light by the first lens 45a, and the parallel light is converged by the second lens 45b and then enters the incident light surface of the optical fiber 481. In order to prevent the reflected light from being reversely reflected back to the laser chip, the incident light surface of the optical fiber 481 is a bevel. In order to use the refraction principle to make the light entering the optical fiber meet the condition of total internal reflection, the light is incident on the non-central position of the second lens 45b, and the light is converged by the non-central part of the second lens 45b. After changing the optical axis direction of the light by the second lens 45b, it is incident on the incident bevel of the optical fiber 481; light refraction occurs on the incident bevel and then enters the optical fiber 481.

[0101] As Figure 22A shown, compared with Figure 21A , the incident light surface of the optical fiber is a bevel, while the central axis of the optical fiber in the optical fiber ferrule remains unchanged. In order to make the refracted light meet the condition of total internal reflection, the converged light certainly cannot maintain Figure 21A this propagation direction. Specifically, if the optical axis maintains Figure 21A the direction in, which is parallel to the light output optical axis direction of the laser chip, then the incident light surface of the light incident in a non-perpendicular direction has a reduced incident angle and a reduced refraction angle, which is not conducive to total internal reflection. In order to increase the incident angle, Figure 22A the scheme in changes Figure 21A the optical axis direction in. The optical axis direction after being converged by the second lens 45b is not parallel to the light output optical axis direction of the laser chip to increase the incident angle during refraction.

[0102] From Figure 22B the simulation diagram in, it can be seen that the light converged by the second lens 45b changes the direction of its optical axis, so that the converged light has a different propagation direction from that in Figure 21B . At this time, the light is converged at a non-central position of the second lens 45b. In order to achieve total internal reflection in the light, the light incident on the light incident surface of the optical fiber 481 has a specific incident angle range, and this angle range also limits that the light converged by the second lens 45b cannot be converged through the center of the second lens 45b.

[0103] However, with Figure 22A this optical path design, the optical axis does not pass through the center of the second lens 45b, and the light changes the direction of the optical axis after passing through the second lens 45b, resulting in a large deformation of the light spot, a distorted light spot shape, an irregular mode field distribution of the light spot, and a significant reduction in the coupling efficiency into the optical fiber.

[0104] Figure 22A and Figure 22B The advantage of this optical path design is that it prevents the reflected light generated on the light incident surface of the optical fiber from returning to the laser chip along the original optical path, and the disadvantage is that the optical path is not converged using the center of the second lens 45b, resulting in a large deterioration of the mode spot shape of the converged light spot.

[0105] Figure 23 It is a simulation diagram of the coupling efficiency of the optical axis passing through the center of the second lens and entering the inclined optical fiber ferrule. As Figure 23 shown, the light incident surface of the optical fiber 481 is an inclined surface. The light emitted by the laser chip 44 is collimated by the first lens 45a and then converged by the second lens 45b and enters the optical fiber 481 of the optical fiber adapter; the light is converged through the center of the second lens 45b, the central axis of the optical fiber is parallel to the illumination of the second lens 45b, and the light is coupled into the optical fiber 481 after refraction. It can be seen that a large amount of light is emitted from the optical fiber 481 of the optical fiber adapter, and the coupling efficiency is low.

[0106] Figure 24A This is a schematic diagram of the optical path structure of the light emission part provided by the embodiment of the present application. Figure 24B It is Figure 24A the simulation diagram of the coupling efficiency of the optical path structure in. As Figure 24A shown, in this embodiment, the central axis of the optical fiber 481 is set to be parallel to the central axis of the optical fiber adapter, and the central axis of the optical fiber adapter is set to be not in the same direction as the light emission optical axis of the laser chip. Furthermore, the light emission optical axis direction of the laser chip is not parallel to the central axis of the optical fiber; the divergent light emitted by the laser chip 44 is converged into parallel light by the first lens 45a, and the parallel light is converged by the second lens 45b and then enters the inclined surface of the optical fiber 481.

[0107] To prevent the reflected light from reversely reflecting back to the laser chip, the light-incident surface of the optical fiber is an inclined surface; to utilize the refraction principle to inject light into the optical fiber, the light emitted by the laser chip exits through the center of the second lens 45b, and the original optical axis direction remains unchanged during the focusing process. When the light enters the inclined light-incident surface of the optical fiber 481, the light is refracted into the optical fiber 481 through the light-incident surface of the optical fiber 481. The signal light is refracted into the optical fiber 481 through the inclined surface, and the inclination angle of the inclined surface and the inclination angle of the optical fiber adapter are coordinately controlled so that the optical axis direction of the signal light refracted into the optical fiber 481 is parallel or nearly parallel to the central axis of the optical fiber 481.

[0108] Figure 24A The provided optical path design aims to maintain a good spot mode shape after the light is converged, and match the light-incident inclined surface of the optical fiber 481. The optical axis direction of the signal light refracted into the optical fiber 481 is parallel to the central axis of the optical fiber 481 to complete the efficient coupling of light into the optical fiber.

[0109] To maintain a good spot mode shape after the light is converged, the light is converged through the center of the second lens 45b. The light exits through the center of the second lens 45b, and the optical axis direction after focusing remains unchanged. The light after convergence maintains the spot shape before convergence and can maintain a circular spot shape under ideal conditions, which is beneficial to improving the efficiency of optical coupling.

[0110] To prevent the reflected light generated by the light-incident surface of the optical fiber from returning to the laser chip along the original optical path, the light-incident surface of the optical fiber ferrule / the light-incident surface of the optical fiber is designed as an inclined surface. However, Figure 21A The shown optical path structure shows that when the light is converged through the center of the second lens 45b, the subsequent light-incident surface of the optical fiber that matches it cannot be an inclined surface in order to satisfy that the light refracted at the light-incident surface can undergo total internal reflection transmission; Figure 22A The shown optical path structure shows that when the light-incident surface is an inclined surface, the light that matches it before cannot be converged through the center of the second lens 45b in order to satisfy that the light refracted at the light-incident surface can undergo total internal reflection transmission.

[0111] To make the light coupled into the optical fiber undergo total internal reflection, the embodiment of the present application provides a new structural design. By inclinedly arranging the optical fiber adapter 48 on the substrate 41, the central axis of the optical fiber 481 is not parallel to the light-emitting direction of the laser chip, and then the optical fiber is inclined at a certain angle relative to the light-emitting direction of the laser chip.

[0112] After the light is refracted into the optical fiber, it forms a specific angular relationship with the central axis of the optical fiber. This angular relationship is Figure 21A 、 Figure 22A and Figure 24A exactly the same in, which is also an inevitable requirement for total internal reflection of light in the optical fiber.

[0113] Such as Figure 24BAs shown, the optical path structure of Figure 24A is adopted, and the light rays are converged through the center of the second lens 45b. The light incident surface of the optical fiber is inclined, and the light converged by the second lens 45b can be coupled into the optical fiber with high efficiency, and most of the light rays enter the optical fiber.

[0114] Figure 22A In Figure 24A , with the inclined light incident surface of the optical fiber as a reference, the incident angle of the light is the same, and the refracted angle of the light is also the same. The difference is that: Figure 22A the central axis of the optical fiber in Figure 24A is parallel to the light emitting direction of the laser chip, and the optical axis passes through the non - central area of the second lens 45b; while in

[0115] the central axis of the optical fiber is not parallel to the light emitting direction of the laser chip, and the optical axis passes through the central area of the second lens 45b. Furthermore, the optical path design provided by the embodiments of the present application enables the optical axis direction of the signal light refracted into the optical fiber 481 to be parallel to the central axis of the optical fiber, and completes the high - efficiency coupling of light into the optical fiber. Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; 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 invention.

Claims

1. An optical module, characterized in that, Comprising: An upper housing and a lower housing; A circuit board disposed between the upper housing and the lower housing; A substrate, the lower surface of which is in contact with the lower housing, and the lower surface of the end of the circuit board is disposed on the upper surface of the end of the substrate; A gasket disposed on the upper surface of the substrate, including an insulating and heat-conducting layer, a grounding metal layer disposed on the upper surface of the insulating and heat-conducting layer, and high-speed signal lines; the ends of the high-speed signal lines are electrically connected to the circuit board by wire bonding for transmitting electrical signals from the circuit board to the laser chip; The laser chip, the cathode of which is fixed on the grounding metal layer and the anode is electrically connected to the high-speed signal lines by wire bonding, for emitting an optical signal based on the electrical signal; A recess is formed in the substrate, and the upper surface of the substrate includes a first upper surface and a second upper surface respectively located on both sides of the recess, wherein: The lower surface of the end of the circuit board is disposed on the first upper surface; A semiconductor cooler is disposed in the recess, the lower surface of the semiconductor cooler is in contact with the bottom of the recess, and the upper surface thereof is provided with the gasket, and the upper surface of the gasket is in the same horizontal plane or approximately in the same horizontal plane as the upper surface of the circuit board; An optical fiber adapter is disposed on the second upper surface, and the optical axis of the optical fiber adapter is in the same horizontal plane or approximately in the same horizontal plane as the optical axis of the light beam emitted by the laser chip; An isolator and an antireflection film are disposed on the second upper surface, the antireflection film is mounted on the end face of the optical fiber adapter, and the isolator is mounted on the antireflection film; 2. The optical module according to claim 1, characterized in that, A focusing lens is further disposed on the upper surface of the semiconductor cooler, wherein: The focusing lens is disposed on the transmission optical path of the light beam emitted by the laser chip for converging the light beam to the optical fiber adapter; 3. The optical module according to claim 1, characterized in that, The optical module further includes: A wire bonding protection component, which is non-conductively fixed on the upper surface of the circuit board and covers the gasket and the wire bonding connecting the gasket and the circuit board; 4. The optical module according to claim 3, characterized in that, The wire bonding protection component includes a protection plate and two or more support members, wherein: One end of the support member is non-conductively fixed on the upper surface of the circuit board and the other end is fixedly connected to the lower surface of the protection plate; The gasket and the wire bonding connecting the gasket and the circuit board are disposed below the protection plate; 5. The optical module according to claim 3, characterized in that, A laser driver chip is further disposed on the circuit board, wherein: The laser driver chip is electrically connected to the circuit board by wire bonding; The wire bonding protection component also covers the laser driver chip; 6. The optical module according to claim 1, characterized in that, The lower surface of the substrate is fixed on the housing of the optical module by a heat-conducting adhesive; 7. The optical module according to any one of claims 1 to 4, characterized in that, The substrate is a tungsten copper substrate.

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