An optical module

Abstract

The optical module provided by the present application includes a circuit board and an optical emission submodule electrically connected to the circuit board, and a mounting hole is provided on the circuit board; the optical emission submodule includes an emission base, a laser, a translation prism and an optical fiber coupler, and the emission base includes a first, a second and a third mounting surface facing the circuit board, the first mounting surface is recessed in the second mounting surface, and the second mounting surface is recessed in the third mounting surface; the third mounting surface is larger than the width dimension of the first mounting surface in the front-to-back direction; the laser is arranged on the third mounting surface and is located on the back side of the circuit board through the mounting hole; the translation prism is arranged on the second mounting surface, and one end thereof is located on the back side of the circuit board through the mounting hole; the optical fiber coupler is arranged on the first mounting surface and is located on the front side of the circuit board. The present application adopts a unique emission base structure to optimize the layout of optical components, reduce the size of the entire optical emission submodule, and at the same time reduce the holes in the circuit board to facilitate high-frequency line wiring and increase the layout area of ​​electronic components.

Description

Technical Field

[0001] The present application relates to the field of optical fiber communication technology, and in particular to an optical module. Background Art

[0002] With the development of new services and application models such as cloud computing, mobile Internet, and video, the development and progress of optical communication technology has become increasingly important. In optical communication technology, optical modules are tools for realizing the mutual conversion of optical and electrical signals, and are one of the key components in optical communication equipment. In addition, with the development of optical communication technology, the transmission rate of optical modules is constantly increasing.

[0003] With the increase of communication rate, the rate requirement of optical modules is getting higher and higher, especially in recent years, 800G optical modules have been gradually introduced to the market. In order to achieve the transmission rate of 800G single module, it is necessary to integrate 8 optical transmitters and 8 optical receivers in the package of QSFP-DD or OSFP. To realize the required functions in such a small space, high-frequency performance, optical performance, heat dissipation characteristics, structural complexity, manufacturability, etc. are all great challenges. Summary of the invention

[0004] The embodiment of the present application provides an optical module, which adopts a special structural design and a reasonable assembly process, greatly simplifies the overall assembly of the module, greatly improves the production efficiency and maintenance efficiency, and is more suitable for mass production.

[0005] The present application provides an optical module, comprising:

[0006] A circuit board having mounting holes disposed thereon;

[0007] An optical transmission submodule, electrically connected to the circuit board, and configured to transmit an optical signal;

[0008] An optical fiber adapter connected to the optical transmission submodule;

[0009] Wherein, the optical emission sub-module comprises:

[0010] The transmitting base comprises a first mounting surface, a second mounting surface and a third mounting surface facing the circuit board, wherein the first mounting surface is recessed in the second mounting surface, and the second mounting surface is recessed in the third mounting surface; the width dimension of the third mounting surface in the front-to-back direction is greater than the width dimension of the first mounting surface in the front-to-back direction;

[0011] A laser, arranged on the third mounting surface, located on the back side of the circuit board through the mounting hole, and used for emitting a laser beam;

[0012] A translation prism is arranged on the second mounting surface, one end of which is located on the back side of the circuit board through the mounting hole, and the other end is located on the front side of the circuit board, and is used to reflect the laser beam located on the back side of the circuit board to the front side of the circuit board;

[0013] The optical fiber coupler is arranged on the first mounting surface and is located on the front side of the circuit board, and is used for coupling the laser beam reflected by the translation prism to the optical fiber adapter.

[0014] The optical module provided in the embodiment of the present application includes a circuit board, an optical transmission sub-module and an optical fiber adapter. The circuit board is provided with a mounting hole. The optical transmission sub-module is electrically connected to the circuit board for transmitting an optical signal. The optical transmission sub-module includes a transmitting base, a laser, a translation prism and an optical fiber coupler. The transmitting base includes a first mounting surface, a second mounting surface and a third mounting surface facing the circuit board. The first mounting surface is recessed in the second mounting surface, and the second mounting surface is recessed in the third mounting surface. The width dimension of the third mounting surface in the front-to-back direction is greater than the width dimension of the first mounting surface in the front-to-back direction. The laser is arranged on the third mounting surface and is located on the back side of the circuit board through the mounting hole, and is used to generate a laser beam. The translation prism is arranged on the second mounting surface, one end of which is located on the back side of the circuit board through the mounting hole, and the other end is located on the front side of the circuit board, and is used to reflect the laser beam located on the back side of the circuit board to the front side of the circuit board. The optical fiber coupler is arranged on the first mounting surface and is located on the front side of the circuit board, and is used to couple the laser beam reflected by the translation prism to the optical fiber adapter. The optical module provided by the present application adopts a unique transmitting base structure to optimize the layout of optical components, thereby reducing the size of the entire optical transmitting submodule, and at the same time can reduce the holes in the circuit board to facilitate high-frequency line wiring and increase the layout area of ​​electronic components. The present application greatly simplifies the assembly of the entire module by adopting a special structural design and a reasonable assembly process, greatly improves production efficiency and maintenance efficiency, and is more suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the connection relationship of optical communication terminals;

[0016] Figure 2 is a schematic diagram of the structure of an optical network unit;

[0017] Figure 3 A schematic diagram of the structure of an optical module provided in an embodiment of the present application;

[0018] Figure 4 A schematic diagram of the decomposed structure of an optical module provided in an embodiment of the present application;

[0019] Figure 5 Schematic diagram of the assembly of a circuit board, an optical transmitting submodule, an optical receiving submodule and an optical fiber adapter in an optical module provided in an embodiment of the present application Figure 1 ;

[0020] Figure 6 A schematic diagram of the structure of a circuit board in an optical module provided in an embodiment of the present application;

[0021] Figure 7 A schematic diagram of the assembly of a circuit board, a light transmitting sub-module and a first optical fiber adapter in an optical module provided in an embodiment of the present application;

[0022] Figure 8 A schematic diagram of a flip structure of a light emitting submodule in an optical module provided in an embodiment of the present application Figure 1 ;

[0023] Fig. 9 A partial schematic diagram of another angle of assembly of a circuit board and a light emitting sub-module in an optical module provided in an embodiment of the present application;

[0024] Fig.10 A side view of an assembly of a circuit board and a light emitting sub-module in an optical module provided in an embodiment of the present application;

[0025] Fig.11 A schematic diagram of an emission light path in an optical module provided in an embodiment of the present application Figure 1 ;

[0026] Fig.12 A schematic diagram of the structure of a transmitting base in an optical module provided in an embodiment of the present application Figure 1 ;

[0027] Fig.13 A schematic diagram of the structure of a transmitting base in an optical module provided in an embodiment of the present application Figure 2 ;

[0028] Fig.14 A schematic diagram of a flip structure of a light emitting submodule in an optical module provided in an embodiment of the present application Figure 2 ;

[0029] Fig.15 A schematic diagram of the structure of a transmitting base in an optical module provided in an embodiment of the present application Figure 3 ;

[0030] Fig.16 A schematic diagram of a flip structure of a light emitting submodule in an optical module provided in an embodiment of the present application Figure 3 ;

[0031] Fig.17 A schematic diagram of an emission light path in an optical module provided in an embodiment of the present application Figure 2 ;

[0032] Fig.18 A schematic diagram of the structure of a transmitting base in an optical module provided in an embodiment of the present application Figure 4 ;

[0033] Fig.19 A schematic diagram of a flip structure of a light emitting submodule in an optical module provided in an embodiment of the present application Figure 4 ;

[0034] Fig. 20 A schematic diagram of the structure of a transmitting base in an optical module provided in an embodiment of the present application Figure 5 ;

[0035] Fig.21 A cross-sectional view of a high-frequency signal line connection of an optical transmission submodule in an optical module provided in an embodiment of the present application;

[0036] Fig. 22 A schematic diagram of high-frequency signal connection of an optical transmission submodule in an optical module provided in an embodiment of the present application;

[0037] Fig.23 A schematic diagram of a heat dissipation channel of an optical module provided in an embodiment of the present application;

[0038] Fig.24 A cross-sectional view of a monitoring optical path of a light detector in an optical module provided in an embodiment of the present application;

[0039] Fig.25 A side view of a monitoring optical path of a light detector in an optical module provided in an embodiment of the present application;

[0040] Fig.26 Schematic diagram of the assembly of a circuit board and a light receiving submodule in an optical module provided in an embodiment of the present application Figure 1 ;

[0041] Fig. 27 A schematic diagram of the structure of the optical part of a light receiving submodule in an optical module provided in an embodiment of the present application;

[0042] Fig.28 A cross-sectional view of a receiving optical path in an optical module provided in an embodiment of the present application;

[0043] Fig.29 Schematic diagram of the assembly of a circuit board, an optical transmitting submodule, an optical receiving submodule and an optical fiber adapter in an optical module provided in an embodiment of the present application Figure 2 ;

[0044] Fig.30 Schematic diagram of the assembly of a circuit board and a light receiving submodule in an optical module provided in an embodiment of the present application Figure 2 ;

[0045] Fig.31 A side view of the assembly of a circuit board and a light receiving sub-module in an optical module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] In order to provide a clear and complete description of the technical solution of the application, some concepts involved in the application are first explained below.

[0047] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] One of the core links of fiber-optic communication is the conversion between optical and electrical signals. Fiber-optic communication uses optical signals carrying information to transmit in optical fiber / optical waveguide and other information transmission equipment. The passive transmission characteristics of light in optical fiber / optical waveguide can achieve low-cost and low-loss information transmission; while information processing equipment such as computers use electrical signals. In order to establish an information connection between information transmission equipment such as optical fiber / optical waveguide and information processing equipment such as computers, it is necessary to achieve the conversion between electrical and optical signals.

[0049] Optical modules realize the above-mentioned mutual conversion function of optical and electrical signals in the field of optical fiber communication technology. The mutual conversion of optical signals and electrical signals is the core function of optical modules. Optical modules realize electrical connection with external host computers through the gold fingers on their internal circuit boards. The main electrical connections include power supply, I2C signals, data signals and grounding. The electrical connection method realized by gold fingers has become the mainstream connection method in the optical module industry. Based on this, the definition of the pins on the gold fingers has formed a variety of industry protocols / specifications.

[0050] Figure 1 Figure 1 is a schematic diagram of the connection relationship of optical communication terminals. Figure 1 As shown, the connection of the optical communication terminal mainly includes the interconnection between the optical network terminal 100, the optical module 200, the optical fiber 101 and the network cable 103;

[0051] One end of the optical fiber 101 is connected to the remote server, and one end of the network cable 103 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 between 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.

[0052] The optical port of the optical module 200 is connected to the optical fiber 101 to establish a bidirectional optical signal connection with the optical fiber 101; the electrical port of the optical module 200 is connected to the optical network terminal 100 to establish a bidirectional electrical signal connection with the optical network terminal 100; the mutual conversion between the optical signal and the electrical signal is realized inside the optical module, so as to establish 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 input into the optical fiber.

[0053] The optical network terminal has an optical module interface 102, which is used to access the optical module 200 and establish a bidirectional electrical signal connection with the optical module 200; the optical network terminal has a network cable interface 104, which is used to access the network cable 103 and establish a bidirectional electrical signal connection with the network cable 103; the optical module 200 and the network cable 103 are connected through the optical network terminal 100. Specifically, the optical network terminal 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 terminal acts as a host computer of the optical module to monitor the operation of the optical module.

[0054] At this point, the remote server establishes a two-way signal transmission channel with the local information processing device through optical fiber, optical module, optical network terminal and network cable.

[0055] Common information processing equipment includes routers, switches, and electronic computers. The optical network terminal is the host computer of the optical module, which provides data signals to the optical module and receives data signals from the optical module. Other common optical module host computers include optical line terminals.

[0056] Figure 2 Figure 1 is a schematic diagram of the optical network terminal structure. Figure 2 As shown, 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 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 protrusions such as fins to increase the heat dissipation area.

[0057] 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 to the optical fiber 101 .

[0058] 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 cage fixes the optical module, and the heat generated by the optical module is conducted to the cage 106 and then diffused through the heat sink 107 on the cage.

[0059] Figure 3A schematic diagram of an optical module structure provided in an embodiment of the present application is provided. Figure 4 This is a schematic diagram of the decomposition structure of the optical module provided in the embodiment of the present application. Figure 3 , Figure 4 As shown, the optical module 200 provided in the embodiment of the present application includes an upper housing 201, a lower housing 202, a circuit board 300, an optical transmitting sub-module 400, an optical receiving sub-module and an optical fiber adapter.

[0060] 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 a square body. 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 third shell, and the third shell 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 third shell and perpendicular to the third shell, and the two side walls are combined with the two side panels to realize the upper shell covering the lower shell.

[0061] The two openings can specifically be two end openings (204, 205) in the same direction, or two openings in different directions; one of the openings is an 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 an optical port 205, which is used for external optical fiber access to connect the optical transmitting submodule 400 and the optical receiving submodule inside the optical module; the optoelectronic devices such as the circuit board 300, the optical transmitting submodule 400, the optical receiving submodule and the optical fiber adapter are located in the package cavity.

[0062] The upper shell and the lower shell are combined to facilitate installation of components such as the circuit board 300, the optical transmitting submodule 400, the optical receiving submodule and the optical fiber adapter into the shell. The upper shell and the lower shell form the outermost packaging protection shell of the optical module. The upper shell and the lower shell are generally made of metal materials, which is conducive to electromagnetic shielding and heat dissipation. The shell of the optical module is generally not made into an integrated component. In this way, when assembling components such as circuit boards, positioning components, heat dissipation and electromagnetic shielding components cannot be installed, which is not conducive to production automation.

[0063] The optical module provided in the present application also includes an unlocking component, which is located on the outer wall of the encapsulating cavity / lower shell 202 and is used to achieve a fixed connection between the optical module and the host computer, or to release the fixed connection between the optical module and the host computer.

[0064] The unlocking component has a locking component that matches the cage of the host computer; pulling the end of the unlocking component can make the unlocking component move relatively on the surface of the outer wall; the optical module is inserted into the cage of the host computer, and the locking component of the unlocking component fixes the optical module in the cage of the host computer; by pulling the unlocking component, the locking component of the unlocking component moves accordingly, thereby changing the connection relationship between the locking component and the host computer, so as to release the locking relationship between the optical module and the host computer, so that the optical module can be pulled out of the cage of the host computer.

[0065] Circuit traces, electronic components (such as capacitors, resistors, transistors, MOS tubes) and chips (such as MCU, laser driver chip, high-frequency photoelectric receiving diode, transimpedance amplifier (TIA), clock data recovery CDR, power management chip, data processing chip DSP) are arranged on the circuit board 300. The circuit board connects the electrical components in the optical module according to the circuit design through the circuit traces to realize electrical functions such as power supply, electrical signal transmission and grounding.

[0066] Circuit boards are generally rigid circuit boards. Rigid circuit boards can also perform load-bearing functions due to their relatively hard material. For example, rigid circuit boards can stably carry chips. When optical transceivers are located on the circuit boards, rigid circuit boards can also provide stable load-bearing. Rigid circuit boards can also be inserted into electrical connectors in the cage of the host computer. Specifically, metal pins / gold fingers are formed on the end surface of one side of the rigid circuit board for connecting to the electrical connector. These are not easy to achieve with flexible circuit boards.

[0067] Flexible circuit boards are also used in some optical modules as a supplement to rigid circuit boards. Flexible circuit boards are generally used in conjunction with rigid circuit boards. For example, flexible circuit boards can be used to connect rigid circuit boards to optical transceiver devices.

[0068] Figure 5 This is a schematic diagram of the assembly of the circuit board, the optical transmitting submodule, the optical receiving submodule and the optical fiber adapter in the optical module provided in the embodiment of the present application. Figure 5As shown, the optical module provided in the embodiment of the present application includes an optical transmitting submodule 400, a first optical receiving submodule 500, a second optical receiving submodule 600, a first optical fiber adapter group 700, a second optical fiber adapter 800 and a third optical fiber adapter 900. The optical transmitting submodule 400 adopts an optical transmitter structure with the bottom facing upward (flip-chip), so that the bottom surface of the optical transmitting submodule 400 is in contact with the upper shell 201, which greatly improves the heat dissipation characteristics of the optical transmitting submodule 400; the emission light beam emitted by the optical transmitting submodule 400 is transmitted to the first optical fiber adapter group 700 through the optical fiber to realize the emission of light. The first optical receiving submodule 500 and the second optical receiving submodule 600 can be arranged on both sides of the optical transmitting submodule 400, and the light beam transmitted by the external optical fiber is transmitted to the first optical receiving submodule 500 through the second optical fiber adapter 800 and the optical fiber, and is transmitted to the second optical receiving submodule 600 through the third optical fiber adapter 900 and the optical fiber, thereby realizing the reception of multiple light beams.

[0069] Figure 6 A schematic diagram of the structure of a circuit board in an optical module provided in an embodiment of the present application, Figure 7 This is a schematic diagram of the assembly of the circuit board, the optical transmission sub-module and the first optical fiber adapter in the optical module provided in the embodiment of the present application. Figure 6 , Figure 7 As shown, a mounting hole 320 is provided on the circuit board 300, and the laser component of the optical emission sub-module 400 is embedded in the mounting hole 320 to bring the laser component close to the lower surface (back side) of the circuit board 300. In this way, the optical emission sub-module 400 is reversely assembled to the circuit board 300, so that during assembly, the wiring surface height of the laser component is the same as the back side of the circuit board 300, thereby making the connection wiring between the back side of the circuit board 300 and the laser component as short as possible to ensure excellent high-frequency transmission performance.

[0070] Figure 8 Schematic diagram of the flip structure of the light emitting submodule in the optical module provided in the embodiment of the present application Figure 1 , Fig. 9 This is a schematic diagram of the partial assembly of the circuit board and the light emitting sub-module in the optical module provided in the embodiment of the present application from another angle. Figure 8 , Fig. 9As shown, the optical transmitting submodule 400 may include a transmitting base 410 and a laser 420, a collimating lens 430, a translation prism 440, an optical isolator and an optical fiber coupler arranged on the transmitting base 410. The bottom surface of the transmitting base 410 (the surface facing away from the mounting surface) faces the upper shell 201, and the mounting surface of the transmitting base 410 faces the circuit board 300. The laser 420, the collimating lens 430, the translation prism 440, the optical isolator and the optical fiber coupler are all mounted on the mounting surface of the transmitting base 410, and the mounting height of the laser 420, the collimating lens 430 and the translation prism 440 is higher than the mounting height of the optical isolator and the optical fiber coupler, so that the laser 420, the collimating lens 430 and the translation prism 440 are located on the back side of the circuit board 300 through the mounting hole 320 on the circuit board 300, and the optical isolator and the optical fiber coupler are located on the front side of the circuit board 300.

[0071] A laser beam emitted by the laser 420 is converted into a collimated beam via a collimating lens 430. The collimated beam is reflected from the back side of the circuit board 300 to the front side of the circuit board 300 via a translation prism 440. The laser beam reflected by the translation prism 440 is directly emitted into the optical fiber coupler through the optical isolator. The laser beam is coupled to the first optical fiber adapter group 700 via the optical fiber coupler, thereby realizing the emission of an optical signal.

[0072] For optical modules with high transmission rates, such as 800G optical modules, in order to achieve the transmission rate of 800G optical modules, it is necessary to integrate 8 optical transmitters and 8 optical receivers in the QSFP-DD or OSFP package. Therefore, the optical transmission submodule 400 includes 8 optical transmitters to achieve the transmission of 8 optical transmission light beams; the first optical receiving submodule 500 includes 4 optical receivers to achieve the reception of 4 receiving light beams; the second optical receiving submodule 600 includes 4 optical receivers to achieve the reception of 4 receiving light beams.

[0073] Based on this, the optical transmission submodule 400 may also include a transmission base 410 and a plurality of lasers 420, a plurality of collimating lenses 430, a translation prism 440, a first optical combiner 4510, a second optical combiner 4520, a first optical isolator 4610, a second optical isolator 4620, a first optical fiber coupler 4710 and a second optical fiber coupler 4720 arranged on the transmission base 410, wherein the bottom surface of the transmission base 410 faces the upper housing 201, and the mounting surface of the transmission base 410 faces the circuit board 300, and the plurality of lasers 420, the plurality of collimating lenses 430, the translation prism 440, the first optical combiner 4510, the second optical combiner 4520, the first optical isolator 4610, the second optical isolator 4620, the first optical fiber coupler 4710 and the second optical fiber coupler 4720. The prism 440, the first optical combiner 4510, the second optical combiner 4520, the first optical isolator 4610, the second optical isolator 4620, the first optical fiber coupler 4710 and the second optical fiber coupler 4720 are all installed on the mounting surface of the transmitting base 410, and the mounting height of the laser 420, the collimating lens 430 and the translation prism 440 is higher than the mounting height of the first optical combiner 4510, the second optical combiner 4520, the first optical isolator 4610, the second optical isolator 4620, the first optical fiber coupler 4710 and the second optical fiber coupler 4720.

[0074] In the embodiment of the present application, the light emitting submodule 400 includes 8 lasers 420, 8 collimating lenses 430 and a translation prism 440. The lasers 420 and the collimating lenses 430 are arranged in a one-to-one correspondence. Each laser 420 emits a laser beam, and each collimating lens 430 converts a laser beam into a collimated beam. The collimated beam emitted by each collimating lens 430 is transmitted to the translation prism 440, and the collimated beam is reflected by the translation prism 440 to change the transmission direction and position of the laser beam.

[0075] After the multiple laser light beams located on the back side of the circuit board 300 are reflected to the front side of the circuit board 300 by the translation prism 440, the multiple laser light beams are synthesized into two composite light beams through the first optical combiner 4510 and the second optical combiner 4520. The two composite light beams are coupled to the first optical fiber adapter group 700 through the first optical fiber coupler 4710 and the second optical fiber coupler 4720 respectively, thereby realizing the transmission of multiple optical signals.

[0076] For the 800G optical module, the first optical fiber adapter group 700 connected to the optical transmission sub-module 400 includes a first optical fiber adapter 710 and a fourth optical fiber adapter 720. The first optical fiber adapter 710 is coupled to the first optical fiber coupler 4710 of the optical transmission sub-module 400 through an internal optical fiber to achieve the emission of one composite light beam; the fourth optical fiber adapter 720 is connected to the second optical fiber coupler 4720 of the optical transmission sub-module 400 through another internal optical fiber to achieve the emission of another composite light beam.

[0077] Fig.10This is a partial assembly side view of the circuit board and the light emitting submodule in the optical module provided in the embodiment of the present application. Fig.10 As shown, the transmitting base 410 of the optical transmitting sub-module 400 is installed on the front side of the circuit board 300, and multiple lasers 420 and multiple collimating lenses 430 installed on the transmitting base 410 are located on the back side of the circuit board 300 through the mounting holes 320. One end of the translation prism 440 is located on the back side of the circuit board 300 through the mounting hole 320, and the other end of the translation prism 440 is located on the front side of the circuit board 300. The first optical combiner 4510, the second optical combiner 4520, the first optical isolator 4610, the second optical isolator 4620, the first optical fiber coupler 4710 and the second optical fiber coupler 4720 are all located on the front side of the circuit board 300.

[0078] Multiple lasers 420 emit laser beams respectively, which are parallel to the back side of the circuit board 300; multiple collimating lenses 430 convert the laser beams emitted by the lasers 420 into collimated beams, and the multiple collimated beams are transmitted to the translation prism 440, which reflects the laser beams located on the back side of the circuit board 300 to the front side of the circuit board 300.

[0079] The function of the translation prism 440 is to translate the 8 light beams upward by a certain distance, so that all subsequent optical devices are located on the positive side of the circuit board 300 and maintain an appropriate gap with the circuit board 300. In this way, the position conflict between the optical device and the circuit board 300 is avoided, so that the hole area of ​​the circuit board 300 can be reduced as much as possible, the arrangement area of ​​the electronic devices on the circuit board 300 is increased, and the wiring of the circuit board 300 is easier.

[0080] In an embodiment of the present application, the translation prism 440 includes a first reflector 4410 and a second reflector 4420. The first reflector 4410 faces the collimating lens 430 and is located on the back side of the circuit board 300, and is used to reflect the collimated light beam parallel to the back side of the circuit board 300 into a collimated light beam perpendicular to the circuit board 300; the second reflector 4420 faces the first reflector 4410 and is located on the front side of the circuit board 300, and is used to reflect the collimated light beam perpendicular to the circuit board 300 into a collimated light beam parallel to the front side of the circuit board 300.

[0081] The first optical combiner 4510 and the second optical combiner 4520 are arranged side by side on the mounting surface of the transmitting base 410, that is, the first optical combiner 4510 and the second optical combiner 4520 are arranged side by side along the front-to-back direction of the transmitting base 410, and the optical input ends of the first optical combiner 4510 and the second optical combiner 4520 are oriented toward the optical output end of the translation prism 440, so that 8 laser light beams parallel to the front side of the circuit board 300 are respectively injected into the first optical combiner 4510 and the second optical combiner 4520, among which 4 laser light beams are injected into the first optical combiner 4510, and the first optical combiner 4510 synthesizes the 4 laser light beams into a composite light beam; the remaining 4 laser light beams are injected into the second optical combiner 4520, and the second optical combiner 4520 synthesizes the 4 laser light beams into another composite light beam.

[0082] The right side of the first optical combiner 4510 includes four light input ports for incident signal lights of multiple wavelengths, each light input port is used to incident signal lights of one wavelength; the left side of the first optical combiner 4510 includes a light output port for emitting light. Taking the first optical combiner 4510 as an example, the four wavelengths of λ1, λ2, λ3 and λ4 are incident on the first optical combiner 4510, the λ1 signal light enters the first optical combiner 4510 through the first light inlet, and is reflected six times at six different positions in the first optical combiner 4510 to reach the light outlet; the λ2 signal light enters the first optical combiner 4510 through the second light inlet, and is reflected four times at four different positions in the first optical combiner 4510 to reach the light outlet; the λ3 signal light enters the first optical combiner 4510 through the third light inlet, and is reflected twice at two different positions in the first optical combiner 4510 to reach the light outlet; the λ4 signal light enters the first optical combiner 4510 through the fourth light inlet, and is directly transmitted to reach the light outlet. In this way, the first optical combiner 4510 realizes that signal lights of different wavelengths are input through different light inlets and output through the same light outlet, thereby realizing the light combination of signal lights of different wavelengths.

[0083] The optical input end of the first optical fiber coupler 4710 is coupled to the optical output end of the first optical combiner 4510, and the optical output end of the first optical fiber coupler 4710 is connected to the first optical fiber adapter 710 through an internal optical fiber. In this way, the composite light beam output by the first optical combiner 4510 is coupled to the internal optical fiber through the first optical fiber coupler 4710, and then transmitted to the first optical fiber adapter 710 through the internal optical fiber to realize the emission of a composite light beam.

[0084] The optical input end of the second optical fiber coupler 4720 is coupled to the optical output end of the second optical combiner 4520, and the optical output end of the second optical fiber coupler 4720 is connected to the fourth optical fiber adapter 720 through another internal optical fiber. In this way, the composite light beam output by the second optical combiner 4520 is coupled to the internal optical fiber through the second optical fiber coupler 4720, and then transmitted to the fourth optical fiber adapter 720 through the internal optical fiber to realize the emission of another composite light beam.

[0085] There is a gap between the light output surface of the first optical combiner 4510 and the light input surface of the first optical fiber coupler 4710. When the composite light beam output by the first optical combiner 4510 is transmitted to the light input surface of the first optical fiber coupler 4710, the light will be reflected when propagating at the interface of different media. When the composite light beam is transmitted to the light input surface of the first optical fiber coupler 4710, the reflection will occur. The reflected light beam may return to the laser 420 along the original path, affecting the high-frequency performance of the laser 420. In order to avoid this problem, the first optical isolator 4610 is arranged between the first optical combiner 4510 and the first optical fiber coupler 4710. When the composite light beam emitted by the first optical combiner 4510 is reflected at the light input surface of the first optical fiber coupler 4710, the first optical isolator 4610 is used to isolate the reflected light beam to prevent the reflected light beam from returning to the laser 420 along the original path.

[0086] Similarly, there is a gap between the light output surface of the second optical combiner 4520 and the light input surface of the second optical fiber coupler 4720. When another composite light beam output by the second optical combiner 4520 is transmitted to the light input surface of the second optical fiber coupler 4720, light will be reflected when propagating at the interface of different media. When the composite light beam is transmitted to the light input surface of the second optical fiber coupler 4720, it will be reflected. The reflected light beam may return to the laser 420 along the original path, affecting the high-frequency performance of the laser 420. In order to avoid this problem, the second optical isolator 4620 is arranged between the second optical combiner 4520 and the second optical fiber coupler 4720. When the composite light beam emitted by the second optical combiner 4520 is reflected at the light input surface of the second optical fiber coupler 4720, the second optical isolator 4620 is used to isolate the reflected light beam to prevent the reflected light beam from returning to the laser 420 along the original path.

[0087] In the embodiment of the present application, the first optical fiber coupler 4710 includes a sleeve, a focusing lens 4730 and a first single-mode optical fiber flange 4740. The sleeve is sleeved on the outside of the focusing lens 4730 and the first single-mode optical fiber flange 4740, and the internal optical fiber is inserted into the first single-mode optical fiber flange 4740. The light incident surface of the focusing lens 4730 faces the first optical isolator 4610, and the light output surface faces the first single-mode optical fiber flange 4740. The composite light beam output by the first optical combiner 4510 is transmitted to the focusing lens 4730 through the first optical isolator 4610, and the focusing lens 4730 converges the composite light beam to the internal optical fiber inserted in the first single-mode optical fiber flange 4740.

[0088] The focusing lens 4730 is a cylindrical lens, and the outer diameter of the cylindrical lens and the first single-mode fiber flange 4740 may be slightly smaller than the inner diameter of the sleeve to ensure the coupling degree between the focusing lens 4730 and the first single-mode fiber flange 4740. When the focusing lens 4730 and the first single-mode fiber flange 4740 are inserted into the sleeve, in order to improve the coupling degree between the focusing lens 4730 and the first single-mode fiber flange 4740, the focusing lens 4730 and the first single-mode fiber flange 4740 may only be moved axially.

[0089] In order to facilitate the composite light beam passing through the first optical isolator 4610 to enter the focusing lens 4730, the focusing lens 4730 protrudes out of the sleeve, reducing the distance between the light incident surface of the focusing lens 4730 and the light emitting surface of the first optical isolator 4610, making the structure more compact.

[0090] Fig.11 This is a cross-sectional view of the light emission path in the optical module provided in the embodiment of the present application. Fig.11As shown, the laser 420 emits a laser beam, which is transmitted to the collimating lens 430. The collimating lens 430 converts the laser beam into a collimated beam, which is transmitted to the first reflector 4410 of the translation prism 440. The first reflector 4410 reflects the collimated beam parallel to the back of the circuit board 300 as a collimated beam perpendicular to the circuit board 300; the collimated beam perpendicular to the circuit board 300 is transmitted to the second reflector 4420 of the translation prism 440, and the second reflector 4420 reflects the collimated beam perpendicular to the circuit board 300 as a laser beam parallel to the front of the circuit board 300, thereby reflecting the laser beam located on the back side of the circuit board 300 as a laser beam located on the front side of the circuit board 300; 4 of the 8 laser beams output by the second reflector 4420 are transmitted to the first optical combiner 4510, and the other 4 The laser beam is transmitted to the second optical combiner 4520; the first optical combiner 4510 multiplexes the four laser beams into one multiplexed beam, and the second optical combiner 4520 multiplexes the four laser beams into another multiplexed beam; the multiplexed beam output by the first optical combiner 4510 is transmitted to the first optical fiber coupler 4710 through the first optical isolator 4610, and the multiplexed beam is converted into a convergent beam via a focusing lens 4730, and the convergent beam is transmitted to the internal optical fiber inserted in the first single-mode optical fiber flange 4740 to realize the emission of one multiplexed beam; the multiplexed beam output by the second optical combiner 4520 is transmitted to the second optical fiber coupler 4720 through the second optical isolator 4620, and the multiplexed beam is converted into a convergent beam via a focusing lens, and the convergent beam is transmitted to the internal optical fiber inserted in the single-mode optical fiber flange to realize the emission of another multiplexed beam.

[0091] Fig.12 Schematic diagram of the structure of the transmitting base in the optical module provided in the embodiment of the present application Figure 1 , Fig.13 This is a schematic diagram of another angle structure of the transmitting base in the optical module provided in the embodiment of the present application. Fig.12 , Fig.13As shown, in order to support and fix the laser 420, the collimating lens 430, the translation prism 440, the first optical combiner 4510, the second optical combiner 4520, the first optical isolator 4610, the second optical isolator 4620, the first optical fiber coupler 4710 and the second optical fiber coupler 4720, the transmitting base 410 includes a first mounting surface 4110, a second mounting surface 4120 and a third mounting surface 4130, the first mounting surface 4110 is recessed in the second mounting surface 4120, and the second mounting surface 4120 is recessed in the third mounting surface 4130, that is, the dimension of the third mounting surface 4130 from the front face of the circuit board 300 is smaller than the dimension of the second mounting surface 4120 from the front face of the circuit board 300, and the dimension of the second mounting surface 4120 from the front face of the circuit board 300 is smaller than the dimension of the first mounting surface 4110 from the front face of the circuit board 300, so that the first mounting surface 4110, the second mounting surface 4120 and the third mounting surface 4130 form a step surface.

[0092] In the embodiment of the present application, the first mounting surface 4110, the second mounting surface 4120 and the third mounting surface 4130 are all parallel to the front surface of the circuit board 300, and the front and rear ends of the second mounting surface 4120 are open to facilitate fixing the translation prism 440 on the second mounting surface 4120; the front, rear and left ends of the first mounting surface 4110 are open to facilitate fixing the optical combiner, optical isolator and optical fiber coupler on the first mounting surface 4110. The front and rear ends of the third mounting surface 4130 may be provided with baffles, which face the side of the circuit board 300 and abut against the front side of the circuit board 300.

[0093] The semiconductor refrigerator 480 is placed on the third mounting surface 4130 of the transmitting base 410, each laser 420 is arranged on a laser substrate, each laser substrate is arranged on the cooling surface of the semiconductor refrigerator 480, and the collimating lens 430 corresponding to the laser 420 is arranged on the cooling surface of the semiconductor refrigerator 480, and the collimating lens 430 is arranged in the light emitting direction of the laser 420.

[0094] In the embodiment of the present application, a semiconductor refrigerator 480 is first placed on the third mounting surface 4130 of the transmitting base 410, and 8 lasers 420 and 8 collimating lenses 430 are arranged on the semiconductor refrigerator 480. The 8 lasers 420 are respectively arranged on 8 laser substrates, and the 8 laser substrates are arranged side by side along the front and back directions of the transmitting base 410, so that the 8 lasers 420 emit 8 light beams of different wavelengths.

[0095] The left and right dimensions of the eight laser substrates arranged on the semiconductor cooler 480 can be the same, so that the eight collimating lenses 430 are the same size away from the left and right end faces of the semiconductor cooler 480, thereby arranging the eight lasers 420 and the eight collimating lenses 430 side by side on the semiconductor cooler 480.

[0096] The left and right dimensions of the eight laser substrates arranged on the semiconductor refrigerator 480 may also be different. The laser substrate near the rear side of the semiconductor refrigerator 480 is smaller in size from the right end face of the semiconductor refrigerator 480, and the laser substrate adjacent to the laser substrate is larger in size from the right end face of the semiconductor refrigerator 480, so that the eight laser substrates are fixed on the semiconductor refrigerator 480 in a short, long, short, long, short, long, short, long arrangement; the collimating lens 430 arranged in the light emitting direction of the laser 420 is different in size from the left end face of the semiconductor refrigerator 480, so that when assembling the collimating lens 430, there will be no mutual influence caused by the flow of glue. In this way, by optimizing the design of the laser substrate, the spacing of the multi-channel collimated light can be reduced to reduce the collective size of the entire transmitting base 410, especially the width dimension of the transmitting base 410 in the front and rear directions, so as not to conflict with the light receiving sub-module during assembly.

[0097] In the embodiment of the present application, the width dimension of the third mounting surface 4130 in the front-to-back direction may be slightly larger than the width dimension of the second mounting surface 4120 in the front-to-back direction, and the width dimension of the second mounting surface 4120 in the front-to-back direction may be consistent with the width dimension of the first mounting surface 4110 in the front-to-back direction. When multiple lasers 420 are fixed side by side on the third mounting surface 4130 in the front-to-back direction, the wider third mounting surface 4130 can facilitate the placement of the lasers 420, avoid the close distance between adjacent lasers 420, and thus avoid crosstalk of laser beams emitted by the lasers 420.

[0098] A translation prism 440 is provided on the second mounting surface 4120 recessed in the third mounting surface 4130. The translation prism 440 is vertically fixed on the second mounting surface 4120, and the first reflector 4410 of the translation prism 440 is away from the second mounting surface 4120 and close to the laser 420 on the semiconductor refrigerator 480, and the second reflector 4420 of the translation prism 440 is close to the second mounting surface 4120 and located on the front side of the circuit board 300, so that the laser beam located on the back side of the circuit board 300 is reflected to the front side of the circuit board 300 by the translation prism 440.

[0099] A first optical combiner 4510, a second optical combiner 4520, a first optical isolator 4610, a second optical isolator 4620, a first optical fiber coupler 4710 and a second optical fiber coupler 4720 are arranged on the first mounting surface 4110 recessed in the second mounting surface 4120. The first optical combiner 4510 and the second optical combiner 4520 are arranged side by side along the front-to-back direction of the transmitting base 410, the first optical isolator 4610 and the second optical isolator 4620 are arranged side by side along the front-to-back direction of the transmitting base 410, the first optical fiber coupler 4710 and the second optical fiber coupler 4720 are arranged side by side along the front-to-back direction of the transmitting base 410, and the optical combiner, the optical isolator and the optical fiber coupler are arranged along the light emission direction.

[0100] In the embodiment of the present application, the width dimension of the first mounting surface 4110 in the front-to-back direction is consistent from left to right, and the width dimension of the first mounting surface 4110 in the front-to-back direction may be smaller than the width dimension of the first optical combiner 4510 and the second optical combiner 4520 in the front-to-back direction. In this way, when the first optical combiner 4510 and the second optical combiner 4520 are arranged side by side on the first mounting surface 4110 along the front-to-back direction, one side of the first optical combiner 4510 and one side of the second optical combiner 4520 both protrude from the front and rear sides of the first mounting surface 4110, thereby reducing the size of the transmitting base 410 in the front-to-back direction and saving costs.

[0101] In the embodiment of the present application, the semiconductor refrigerator 480, the laser 420, the collimating lens 430, the translation prism 440, the optical combiner, the optical isolator and the optical fiber coupler are fixed on the transmitting base 410 through the first mounting surface 4110, the second mounting surface 4120 and the third mounting surface 4130 which are arranged in steps, so as to form an installation height difference between the laser 420, the collimating lens 430 and the optical combiner, the optical isolator and the optical fiber coupler, and the laser 420 and the collimating lens 430 with relatively high installation height are arranged on the back side of the circuit board 300 through the mounting hole 320 of the circuit board 300, and the optical combiner, the optical isolator and the optical fiber coupler with relatively low installation height are arranged on the front side of the circuit board 300, so as to reduce the overlapping area of ​​the optical transmitting sub-module 400 and the circuit board 300 in space.

[0102] When assembling the optical emission submodule 400, the semiconductor cooler 480 must first be installed on the third mounting surface 4130, and then the laser 420 must be installed on the laser substrate, and then the laser substrate must be fixed on the semiconductor cooler 480, and then the translation prism 440 must be fixed on the second mounting surface 4120, and then the first optical combiner 4510, the second optical combiner 4520, the first optical isolator 4610, the second optical isolator 4620, the first optical fiber coupler 4710 and the second optical fiber coupler 4720 must be independently fixed on the first mounting surface 4110 according to the light emission direction, and finally the collimating lens 430 must be fixed on the third mounting surface 4130 according to the light emitting direction of the laser 420, and at the same time, the coupling efficiency in the optical fiber must be detected to optimize the position of the collimating lens 430.

[0103] In order to reduce the assembly workload, an integrated optical component can also be used to assemble the first optical combiner 4510, the second optical combiner 4520, the first optical isolator 4610, the second optical isolator 4620, the first fiber coupler 4710, the second fiber coupler 4720, the two internal optical fibers and the first fiber adapter group 700 into a pre-assembled component. First, the semiconductor refrigerator 480 is directly fixed on the third mounting surface 4130, and then the laser 420 is mounted on the laser substrate, and then the laser substrate is fixed on the semiconductor refrigerator 480, and then the translation prism 440 is fixed on the second mounting surface 4120 according to the light emission direction, and then the pre-assembled component is directly fixed on the first mounting surface 4110 of the emission base 410, and finally the collimating lens 430 is fixed on the third mounting surface 4130 according to the light emission direction of the laser 420, and the coupling power in the optical fiber is detected at the same time to optimize the position of the collimating lens 430.

[0104] After the laser 420, the collimating lens 430, the translation prism 440, the first optical combiner 4510, the second optical combiner 4520, the first optical isolator 4610, the second optical isolator 4620, the first optical fiber coupler 4710 and the second optical fiber coupler 4720 are fixedly mounted on the transmitting base 410, the transmitting base 410 is reversely mounted on the front side of the circuit board 300, that is, the bottom surface of the transmitting base 410 faces the upper shell 201, and the first mounting surface 4110, the second mounting surface 4120 and the third mounting surface 4130 of the transmitting base 410 face the front side of the circuit board 300, and then the transmitting base 410 is fixed on the front side of the circuit board 300.

[0105] In order to fix the transmitting base 410 on the front side of the circuit board 300, two support columns 4140 are provided at one end of the first mounting surface 4110 of the transmitting base 410 away from the second mounting surface 4120, and an opening is provided between the two support columns 4140. Two optical fibers respectively connected to the first fiber optic coupler 4710 and the second fiber optic coupler 4720 pass through the opening and are connected to corresponding fiber optic adapters, and the width dimension of the two support columns 4140 in the front-to-back direction is not greater than the width dimension of the first mounting surface 4110 in the front-to-back direction, such that the opposite sides of the two support columns 4140 are flush with the sides of the transmitting base 410.

[0106] The support column 4140 extends from the first mounting surface 4110 toward the front of the circuit board 300, and a first positioning pin 4160 is disposed on the side of the support column 4140 facing away from the first mounting surface 4110. The circuit board 300 is provided with a positioning hole 330, which is disposed corresponding to the first positioning pin 4160.

[0107] A positioning block 4150 is provided at one end of the transmitting base 410 away from the optical fiber adapter, and the positioning block 4150 protrudes from the third mounting surface 4130 toward the side of the circuit board 300, and a positioning pin is provided on the side of the positioning block 4150 toward the circuit board 300, and the positioning pin is arranged corresponding to the positioning hole on the circuit board 300.

[0108] When the transmitting base 410 is reversely installed on the front side of the circuit board 300, the positioning block 4150 of the transmitting base 410 contacts the front side of the circuit board 300 toward the side of the circuit board 300, one end of the support column 4140 contacts the front side of the circuit board 300, and the first positioning pin 4160 on the support column 4140 is inserted into the positioning hole 330 on the circuit board 300, thereby fixing the transmitting base 410 on the circuit board 300, and the laser 420 and the collimating lens 430 arranged on the third mounting surface 4130 and the translation prism 440 arranged on the second mounting surface 4120 are embedded in the mounting hole 320 of the circuit board 300, so that the wire bonding surface height of the laser 420 is flush with the back side of the circuit board 300.

[0109] Fig.14 Schematic diagram of the flip structure of the light emitting submodule in the optical module provided in the embodiment of the present application Figure 2 , Fig.15 Schematic diagram of the structure of the transmitting base in the optical module provided in the embodiment of the present application Figure 3 .like Fig.14 , Fig.15As shown, the transmitting base 410 includes a first mounting surface 4110, a second mounting surface 4120 and a third mounting surface 4130, the first mounting surface 4110 is recessed in the second mounting surface 4120, the second mounting surface 4120 is recessed in the third mounting surface 4130, and the semiconductor refrigerator 480 is arranged on the third mounting surface 4130; the laser 420 is arranged on the laser substrate, and the laser substrate is arranged on the semiconductor refrigerator 480; the collimating lens 430 is arranged on the semiconductor refrigerator 480, and the collimating lens 430 is located in the light emitting direction of the laser 420; the translation prism 440 is arranged on the second mounting surface 4120, and the first reflecting mirror 4410 of the translation prism 440 is arranged in the light emitting direction of the collimating lens 430; the first optical combiner 4510, the second optical combiner 4520, the first optical isolator 4610 and the second optical isolator 4620 are arranged on the first mounting surface 4110 along the light emitting direction.

[0110] A first support block 490 is provided at one end of the first mounting surface 4110 away from the laser 420 . The first support block 490 extends from the first mounting surface 4110 toward the front of the circuit board 300 , and the left end surface of the first support block 490 is flush with the left end surface of the emitting base 410 .

[0111] The first support block 490 is provided with two through holes 4910, which are arranged side by side along the front-to-back direction, and the through holes 4910 penetrate the left end surface and the right end surface of the first support block 490 and communicate with the first mounting surface 4110. The first fiber coupler 4710 and the second fiber coupler 4720 are inserted into the two through holes 4910 on the first support block 490, so as to fix the first fiber coupler 4710 and the second fiber coupler 4720 on the transmitting base 410 through the first support block 490.

[0112] In the embodiment of the present application, the width dimension of the first support block 490 in the front-to-back direction is not greater than the width dimension of the first mounting surface 4110 in the front-to-back direction, so that the width dimension of the left side of the launching base 410 is smaller than the width dimension of the right side, which facilitates processing and saves production costs.

[0113] A second support block 412 is disposed at one end of the launch base 410 away from the first support block 490. The second support block 412 is fixedly connected to the right end surface of the launch base 410. A second positioning pin 4121 is disposed on the second support block 412. A positioning hole 330 is disposed on the circuit board 300, and the positioning hole 330 is disposed corresponding to the second positioning pin 4121.

[0114] When the transmitting base 410 is reversely mounted on the front side of the circuit board 300, one end of the first support block 490 and the second support block 412 are in contact with the front side of the circuit board 300, and the second positioning pin 4121 on the second support block 412 is inserted into the positioning hole 330 on the circuit board 300, thereby fixing the transmitting base 410 on the circuit board 300, and the semiconductor cooler 480 arranged on the third mounting surface 4130, the laser 420 arranged on the semiconductor cooler 480, the collimating lens 430 and the translation prism 440 arranged on the second mounting surface 4120 are embedded in the mounting hole 320 of the circuit board 300, so that the wire bonding surface height of the laser 420 is flush with the back side of the circuit board 300.

[0115] When assembling the optical emission submodule 400, firstly, the laser 420 is mounted on the laser substrate, and then the laser substrate is fixed on the semiconductor refrigerator 480 on the third mounting surface 4130, and then the translation prism 440 is fixed on the second mounting surface 4120, and then the first optical combiner 4510, the second optical combiner 4520, the first optical isolator 4610 and the second optical isolator 4620 are independently fixed on the first mounting surface 4110 according to the light emission direction; then the first optical fiber coupler 4710 and the second optical fiber coupler 4720 are inserted into the through hole 4910 on the first support block 490, and finally the collimating lens 430 is fixed on the third mounting surface 4130 according to the light emitting direction of the laser 420, and at the same time, the coupling power in the optical fiber is detected to optimize the position of the collimating lens 430.

[0116] In the embodiment of the present application, the width dimension of the first mounting surface 4110 located between the first support block 490 and the second mounting surface 4120 in the front-to-back direction is consistent from left to right, and the width dimension of the first mounting surface 4110 in the front-to-back direction may be smaller than the width dimension of the first optical combiner 4510 and the second optical combiner 4520 in the front-to-back direction. In this way, when the first optical combiner 4510 and the second optical combiner 4520 are arranged side by side on the first mounting surface 4110 along the front-to-back direction, one side of the first optical combiner 4510 and one side of the second optical combiner 4520 both protrude from the front and rear sides of the first mounting surface 4110, thereby reducing the size of the transmitting base 410 in the front-to-back direction and saving costs.

[0117] The optical transmission submodule 400 provided in the above embodiment is not only applicable to 800G optical modules, but also to 400G optical modules. The single-channel 100G rate 400G QSFP-DD FR4 solution is taken as an example for explanation. In a multi-optical channel module, the use of the above optical transmission submodule 400 can achieve excellent high-frequency performance, optical performance, heat dissipation characteristics, low structural complexity, high manufacturability and other characteristics in a small space, and can achieve the goal of mass production and cost reduction.

[0118] Fig.16 Schematic diagram of the flip structure of the light emitting submodule in the optical module provided in the embodiment of the present application Figure 3 , Fig.17 Schematic diagram of the transmission light path in the optical module provided in the embodiment of the present application Figure 2 .like Fig.16 , Fig.17 As shown, for the 400G optical module, the optical transmission submodule 400 includes a transmission base 410 and a semiconductor cooler 480, a plurality of lasers 420, a plurality of collimating lenses 430, a translation prism 440, an optical combiner 450, an optical isolator 460 and an optical fiber coupler 470 arranged on the transmission base 410. The bottom surface of the transmission base 410 faces the upper shell 201, and the mounting surface of the transmission base 410 faces the circuit board 300. The semiconductor cooler 480, a plurality of lasers 420, a plurality of collimating lenses 430, a translation prism 440, an optical combiner 450, an optical isolator 460 and an optical fiber coupler 470 are all mounted on the mounting surface of the transmission base 410, and the mounting heights of the lasers 420, the collimating lenses 430 and the translation prism 440 are higher than the mounting heights of the optical combiner 450, the optical isolator 460 and the optical fiber coupler 470.

[0119] In the embodiment of the present application, the light emitting submodule 400 includes a semiconductor refrigerator 480, four lasers 420, four collimating lenses 430 and a translation prism 440. The lasers 420 and the collimating lenses 430 are arranged in a one-to-one correspondence. Each laser 420 emits a laser beam, and each collimating lens 430 converts a laser beam into a collimated beam. The collimated beam emitted by each collimating lens 430 is transmitted to the translation prism 440, and the collimated beam is reflected by the translation prism 440 to change the transmission direction of the laser beam.

[0120] The transmitting base 410 of the optical transmitting submodule 400 is reversely mounted on the front side of the circuit board 300, and multiple lasers 420 and multiple collimating lenses 430 installed on the semiconductor cooler 480 of the transmitting base 410 are located on the back side of the circuit board 300 through the mounting hole 320. One end of the translation prism 440 is located on the back side of the circuit board 300 through the mounting hole 320, and the other end of the translation prism 440 is located on the front side of the circuit board 300. The optical combiner 450, the optical isolator 460 and the fiber coupler 470 are all located on the front side of the circuit board 300.

[0121] The four lasers 420 emit four laser beams respectively, and the laser beams can be parallel to the back side of the circuit board 300; the four laser beams are converted into four collimated beams through four collimating lenses 430, and the four collimated beams are transmitted to the translation prism 440, and the laser beams located on the back side of the circuit board 300 are reflected to the front side of the circuit board 300 through the translation prism 440.

[0122] The function of the translation prism 440 is to translate the four light beams upward by a certain distance, so that all subsequent optical devices are located on the positive side of the circuit board 300 and maintain an appropriate gap with the circuit board 300. In this way, the position conflict between the optical device and the circuit board 300 is avoided, so that the hole area of ​​the circuit board 300 can be reduced as much as possible, the arrangement area of ​​the electronic devices on the circuit board 300 is increased, and the wiring of the circuit board 300 is easier.

[0123] In an embodiment of the present application, the translation prism 440 includes a first reflector 4410 and a second reflector 4420. The first reflector 4410 faces the collimating lens 430 and is located on the back side of the circuit board 300, and is used to reflect the collimated light beam parallel to the back side of the circuit board 300 into a collimated light beam perpendicular to the circuit board 300; the second reflector 4420 faces the first reflector 4410 and is located on the front side of the circuit board 300, and is used to reflect the collimated light beam perpendicular to the circuit board 300 into a collimated light beam parallel to the front side of the circuit board 300.

[0124] The optical combiner 450 and the optical fiber coupler 470 are sequentially arranged according to the light emitting direction of the optical translation prism 440, that is, the four laser beams reflected by the second reflector 4420 of the translation prism 440 are injected into the optical combiner 450, and the optical combiner 450 combines the four laser beams into a composite beam, and the composite beam is injected into the optical fiber coupler 470. The optical fiber coupler includes a sleeve, a focusing lens 4730 and a first single-mode optical fiber flange 4740, the sleeve is sleeved on the outside of the focusing lens 4730 and the first single-mode optical fiber flange 4740, the internal optical fiber is inserted into the first single-mode optical fiber flange 4740, the light incident surface of the focusing lens 4730 faces the optical combiner 450, and the light emitting surface faces the internal optical fiber, the composite beam output by the optical combiner 450 is transmitted to the focusing lens 4730, and the focusing lens 4730 converges the composite beam to the internal optical fiber inserted in the first single-mode optical fiber flange 4740 to achieve light emission.

[0125] There is a gap between the light output surface of the optical combiner 450 and the light input surface of the optical fiber coupler 470. When the composite light beam output by the optical combiner 450 is transmitted to the light input surface of the optical fiber coupler 470, the light will be reflected when it propagates at the interface of different media. When the composite light beam is transmitted to the light input surface of the optical fiber coupler 470, it will be reflected. The reflected light beam may return to the laser 420 along the original path, affecting the light emission performance and high-frequency performance of the laser 420. In order to avoid this problem, the optical isolator 460 is arranged between the optical combiner 450 and the optical fiber coupler 470. When the composite light beam emitted by the optical combiner 450 is reflected at the light input surface of the optical fiber coupler 470, the optical isolator 460 can isolate the reflected light beam and prevent the reflected light beam from returning to the laser 420 along the original path.

[0126] Fig.18Schematic diagram of the structure of the transmitting base in the optical module provided in the embodiment of the present application Figure 4 .like Fig.18 As shown, in order to support and fix the laser 420, the collimating lens 430, the translation prism 440, the optical combiner 450, the optical isolator 460 and the fiber coupler 470, the transmitting base 410 may include a first mounting surface 4110, a second mounting surface 4120 and a third mounting surface 4130. The first mounting surface 4110, the second mounting surface 4120 and the third mounting surface 4130 are all parallel to the front side of the circuit board 300, the first mounting surface 4110 is recessed in the second mounting surface 4120, and the second mounting surface 4120 is recessed in the third mounting surface 4130, so that the first mounting surface 4110, the second mounting surface 4120 and the third mounting surface 4130 form a step surface.

[0127] To facilitate the setting of the step surface, a boss 411 is set at one end of the first mounting surface 4110, and the boss 411 extends from the first mounting surface 4110 in the direction of the circuit board 300. A second mounting surface 4120 and a third mounting surface 4130 are provided on the boss 411. The second mounting surface 4120 is recessed in the third mounting surface 4130, and one end of the second mounting surface 4120 is connected to the first mounting surface 4110, and the other end is connected to the third mounting surface 4130.

[0128] In the embodiment of the present application, the third mounting surface 4130 may be recessed on the side of the boss 411 facing the circuit board 300, so as to facilitate fixing the semiconductor cooler 480 on the third mounting surface 4130, and then mounting the laser 420 on the semiconductor cooler 480. To facilitate mounting the transmitting base 410 on the circuit board 300, a positioning pin is further provided on the side of the boss 411 facing the circuit board 300.

[0129] Each laser 420 is arranged on a laser substrate, and the laser substrate is located on a semiconductor cooler 480 on the third mounting surface 4130 of the emitting base 410. The collimating lens 430 corresponding to the laser 420 is also arranged on the semiconductor cooler 480, and the collimating lens 430 is arranged in the light emitting direction of the laser 420.

[0130] The translation prism 440 is disposed on the second mounting surface 4120, and the first reflector 4410 of the translation prism 440 is away from the second mounting surface 4120 and close to the laser 420 on the third mounting surface 4130, and the second reflector 4420 of the translation prism 440 is close to the second mounting surface 4120 and located on the front side of the circuit board 300, so that the laser beam located on the back side of the circuit board 300 is reflected to the front side of the circuit board 300 by the translation prism 440. The optical combiner 450, the optical isolator 460 and the optical fiber coupler 470 are disposed on the first mounting surface 4110 along the light emission direction.

[0131] In the embodiment of the present application, the width dimension of the third mounting surface 4130 in the front-to-back direction is slightly larger than the width dimension of the second mounting surface 4120 in the front-to-back direction, so as to facilitate the front-to-back arrangement of the four lasers 420 on the third mounting surface 4130. The width dimension of the first mounting surface 4110 in the front-to-back direction is consistent with the width dimension of the boss 411 in the front-to-back direction, and the width dimensions of the two support columns 4140 in the front-to-back direction are consistent with the width dimension of the first mounting surface 4110 in the front-to-back direction, that is, the width dimension of the transmitting base 410 in the front-to-back direction is consistent from left to right, so that it is convenient to arrange the boss 411 and the support column 4140 on the first mounting surface 4110, saving process costs.

[0132] Since the width dimension of the first mounting surface 4110 in the front-to-back direction is the same as the width dimension of the boss 411 in the front-to-back direction, and the width dimension of the third mounting surface 4130 in the front-to-back direction is smaller than the width dimension of the boss 411 in the front-to-back direction, the first mounting surface 4110 is larger than the width dimension of the third mounting surface 4130 in the front-to-back direction. In order to match the multiple lasers 420 on the third mounting surface 4130, the width dimension of the optical combiner 450 in the front-to-back direction is smaller than the width dimension of the first mounting surface 4110 in the front-to-back direction.

[0133] The semiconductor refrigerator 480, the laser 420, the collimating lens 430, the translation prism 440, the optical combiner 450, the optical isolator 460 and the optical fiber coupler 470 are fixed on the transmitting base 410 through the first mounting surface 4110, the second mounting surface 4120 and the third mounting surface 4130 which are arranged in steps, so as to form an installation height difference between the laser 420, the collimating lens 430 and the optical combiner 450, the optical isolator 460 and the optical fiber coupler 470, and the laser 420 and the collimating lens 430 with relatively high installation height are arranged on the back side of the circuit board 300 through the mounting hole 320 of the circuit board 300, and the optical combiner 450, the optical isolator 460 and the optical fiber coupler 470 with relatively low installation height are arranged on the front side of the circuit board 300, so as to reduce the overlapping area of ​​the optical transmitting sub-module 400 and the circuit board 300 in space and reduce the hole digging area of ​​the circuit board.

[0134] When assembling the optical emission submodule 400, first fix the semiconductor cooler 480 on the third mounting surface 4130, then install the laser substrate with the laser 420 mounted on the semiconductor cooler, then fix the translation prism 440 on the second mounting surface 4120, then independently fix the optical combiner 450, the optical isolator 460 and the fiber coupler 470 on the first mounting surface 4110 according to the light emission direction, and finally fix the collimating lens 430 on the third mounting surface 4130 according to the light emitting direction of the laser 420, and at the same time detect the coupling power in the optical fiber to optimize the position of the collimating lens 430.

[0135] In the embodiment of the present application, the optical combiner 450, the optical isolator 460, the fiber coupler 470 and the internal optical fiber can adopt an integrated structure, and the optical combiner 450, the optical isolator 460, the fiber coupler 470, the internal optical fiber and the fiber adapter are assembled into a pre-assembled accessory. When assembling the optical transmission sub-module 400, it is only necessary to fix the pre-assembled accessory directly on the first mounting surface 4110 of the transmission base 410, and then perform the coupling operation through the collimating lens.

[0136] After the semiconductor cooler 480, the laser 420, the collimating lens 430, the translation prism 440, the optical combiner 450, the optical isolator 460 and the fiber coupler 470 are fixedly mounted on the transmitting base 410, the transmitting base 410 is reversely mounted on the front side of the circuit board 300, that is, the bottom surface of the transmitting base 410 faces the upper shell 201, and the first mounting surface 4110, the second mounting surface 4120 and the third mounting surface 4130 of the transmitting base 410 face the front side of the circuit board 300, and then the transmitting base 410 is fixed on the front side of the circuit board 300.

[0137] In order to fix the transmitting base 410 on the front of the circuit board 300, two support columns 4140 are provided at one end of the first mounting surface 4110 of the transmitting base 410 away from the second mounting surface 4120, and an opening is provided between the two support columns 4140, through which the fiber coupler 470 is connected to the fiber adapter. The support column 4140 extends from the first mounting surface 4110 to the direction close to the front of the circuit board 300, and a first positioning pin 4160 is provided on the side of the support column 4140 facing away from the first mounting surface 4110, and the first positioning pin 4160 is provided corresponding to the positioning hole 330 on the circuit board 300.

[0138] When the launching base 410 is installed in reverse, the side of the boss 411 on the launching base 410 contacts the front of the circuit board 300, the side of the support column 4140 on the launching base 410 contacts the front of the circuit board 300, the positioning pin on the boss 411 is inserted into the positioning hole 330 on the circuit board 300, and the first positioning pin 4160 on the support column 4140 is also inserted into the corresponding positioning hole 330 on the circuit board 300, thereby fixing the launching base 410 on the circuit board 300.

[0139] Fig.19 Schematic diagram of the flip structure of the light emitting submodule in the optical module provided in the embodiment of the present application Figure 4 , Fig. 20 Schematic diagram of the structure of the transmitting base in the optical module provided in the embodiment of the present application Figure 5 .like Fig.19 , Fig. 20As shown, in order to support and fix the laser 420, the collimating lens 430, the translation prism 440, the optical combiner 450, the optical isolator 460 and the fiber coupler 470, the transmitting base 410 can also be a square base, and a groove 414 is provided on the transmitting base 410, and the groove 414 is provided with an opening on the side of the circuit board 300, and the bottom surface of the groove 414 is provided with a first mounting surface 4110, a second mounting surface 4120 and a third mounting surface 4130, the first mounting surface 4110, the second mounting surface 4120 and the third mounting surface 4130 are all parallel to the front side of the circuit board 300, the first mounting surface 4110 is recessed in the second mounting surface 4120, and the second mounting surface 4120 is recessed in the third mounting surface 4130, so that the bottom surface of the groove 414 forms a step surface. A fixing hole 413 is provided on the side of the transmitting base 410 facing the optical fiber adapter. The fixing hole 413 is connected to the groove 414. The optical fiber coupler 470 is inserted into the fixing hole 413, and the single-mode optical fiber flange in the optical fiber coupler 470 faces the optical fiber adapter, and the focusing lens in the optical fiber coupler 470 faces the laser 420.

[0140] Each laser 420 is arranged on a laser substrate, and the laser substrate is arranged on a semiconductor cooler 480 on the third mounting surface 4130 of the groove 414. The collimating lens 430 corresponding to the laser 420 is also arranged on the semiconductor cooler 480, and the collimating lens 430 is arranged in the light emitting direction of the laser 420.

[0141] The translation prism 440 is disposed on the second mounting surface 4120 of the groove 414, and the first reflector 4410 of the translation prism 440 is away from the second mounting surface 4120 and close to the laser 420 on the third mounting surface 4130, and is located on the back side of the circuit board 300; the second reflector 4420 of the translation prism 440 is close to the second mounting surface 4120 and is located on the front side of the circuit board 300, so that the laser beam located on the back side of the circuit board 300 is reflected to the front side of the circuit board 300 by the translation prism 440.

[0142] The optical combiner 450 and the optical isolator 460 are arranged on the first mounting surface 4110 of the groove 414 along the light emission direction. The four laser light beams reflected by the translation prism 440 are combined into a composite light beam through the optical combiner 450. The composite light beam is emitted into the focusing lens in the optical fiber coupler 470 through the optical isolator 460. The focusing lens converges and couples the composite light beam into the internal optical fiber inserted into the single-mode optical fiber flange to realize light emission.

[0143] In the embodiment of the present application, the width dimension of the third mounting surface 4130 in the front-to-back direction is slightly larger than the width dimension of the second mounting surface 4120 in the front-to-back direction, so as to facilitate the front-to-back arrangement of the four lasers 420 on the third mounting surface 4130. The width dimension of the first mounting surface 4110 in the front-to-back direction is consistent with the width dimension of the second mounting surface 4120 in the front-to-back direction, and the width dimension of the transmitting base 410 in the front-to-back direction is consistent from left to right.

[0144] The width dimension of the first mounting surface 4110 in the front-to-back direction is the same as the width dimension of the groove 414 . The optical combiner 450 is embedded in the groove 414 , so the width dimension of the optical combiner 450 in the front-to-back direction can be consistent with the width dimension of the first mounting surface 4110 in the front-to-back direction.

[0145] When assembling the optical transmission submodule 400, the optical combiner 450, the optical isolator 460, the fiber coupler 470 and the internal optical fiber are discrete components. First, the laser 420 is mounted on the laser substrate, and then the laser substrate is fixed on the semiconductor refrigerator 480 on the third mounting surface 4130, and then the translation prism 440 is fixed on the second mounting surface 4120, and then the optical combiner 450 and the optical isolator 460 are independently fixed on the first mounting surface 4110 according to the light emission direction, and then the fiber coupler 470 is inserted into the fixing hole 413 on the transmitting base 410, and finally the collimating lens 430 is fixed on the third mounting surface 4130 according to the light emitting direction of the laser 420, and at the same time, the coupling power in the optical fiber is detected to optimize the position of the collimating lens 430.

[0146] The light emitting submodule 400 in the optical module provided in the embodiment of the present application is assembled in reverse so that the wire bonding surface height of the laser 420 is the same as the back of the circuit board 300 during assembly, so that the connection wire bonding between the two is the shortest to ensure excellent high-frequency transmission performance. The unique layout of optical components can reduce the size of the entire light emitting submodule 400, while reducing the digging of the circuit board 300 to facilitate high-frequency line wiring and increase the layout area of ​​electronic components. By optimizing the design of the laser substrate, the spacing of the multi-path collimated light is reduced to reduce the geometric dimensions of the entire light emitting submodule 400, especially the width, so that there is no conflict with the light receiving submodule during assembly. In order to reduce the assembly workload, the optical combiner, optical isolator, fiber coupler, internal optical fiber and fiber adapter are integrated for integrated assembly.

[0147] Fig.21 This is a cross-sectional view of the high-frequency signal line connection of the optical transmission submodule in the optical module provided in the embodiment of the present application. Fig.21As shown, a chip processing chip (Digital Signal Process, DSP) 310 is arranged on the front side of the circuit board 300. The DSP chip 310 is used for processing high-frequency signals and transmitting high-frequency signals to the laser 420 of the optical transmission submodule 400, providing a signal for the laser beam emitted by the laser 420, so that the laser 420 generates signal light. In order to transmit the high-frequency signal of the DSP chip 310 to the laser 420, a high-frequency signal via 340 is arranged under the Tx output pad of the DSP chip 310. The high-frequency signal via 340 runs through the front and back sides of the circuit board 300. A high-frequency signal line is arranged in the high-frequency signal via 340. The high-frequency signal line passes through the high-frequency signal via 340 and is electrically connected to the Tx output pad of the DSP chip 310 to transmit the high-frequency signal.

[0148] Since the bonding surface height of the laser 420 in the optical transmission submodule 400 is flush with the back of the circuit board 300, the high-frequency signal line passes through the high-frequency signal via 340 and is routed along the back of the circuit board 300, and then is electrically connected to the laser 420 through bonding, that is, one end of the high-frequency signal line is electrically connected to the Tx output pad of the DSP chip 310, and the other end is located on the back of the circuit board 300 and is electrically connected to the laser 420 through bonding. The high-frequency signal transmitted from the gold finger end of the circuit board 300 is processed by the DSP chip 310 and then transmitted to the laser 420 via the high-frequency signal line, so that the laser 420 emits signal light.

[0149] In the embodiment of the present application, the mounting surface at one end of the transmitting base 410 is arranged corresponding to the mounting hole 320 of the circuit board 300, and there is a cavity between the mounting surface at the other end of the transmitting base 410 and the front face of the circuit board 300 to install the related optical devices of the optical transmitting sub-module 400. Specifically, the third mounting surface 4130 of the transmitting base 410 is arranged corresponding to the mounting hole 320, the laser 420 is arranged on the third mounting surface 4130, and the laser 420 is located on the back side of the circuit board 300 through the mounting hole 320; the second mounting surface 4120 of the transmitting base 410 is arranged corresponding to the mounting hole 320, the translation prism 440 is arranged on the second mounting surface 4120, and the translation prism 440 is located on the back side of the circuit board 300 through the mounting hole 320; there is a cavity between the first mounting surface 4110 of the transmitting base 410 and the front side of the circuit board 300, and optical devices such as optical combiners, optical isolators, and optical fiber couplers are arranged on the first mounting surface 4110, and are located in the cavity between the first mounting surface 4110 and the circuit board 300.

[0150] The DSP chip 310 located on the front side of the circuit board 300 transmits the high-frequency signal on the circuit board 300 from the front side of the circuit board 300 to the back side of the circuit board 300 through the high-frequency signal line connected to its Tx output pad, so as to transmit the high-frequency signal to the laser 420 located on the back side of the circuit board 300, thereby realizing the high-frequency signal connection between the optical transmission sub-module 400 and the circuit board 300.

[0151] Fig. 22 This is a schematic diagram of high-frequency signal connection of the optical transmission submodule in the optical module provided in the embodiment of the present application. Fig. 22 As shown, a plurality of high-frequency signal vias 340 on the circuit board 300 are arranged on the right side of the mounting hole 320, and each high-frequency signal via 340 is connected to the laser 420 in a one-to-one correspondence, so that the high-frequency signal line passing through each high-frequency signal via 340 is connected to the laser 420, and the high-frequency signal transmitted by the circuit board 300 is transmitted to the laser 420 to meet the high-frequency signal required by the optical emission sub-module 400.

[0152] A DC signal line is also arranged on the back of the circuit board 300, and the DC signal line is electrically connected to the laser 420, and the bias current transmitted through the DC signal line drives the laser 420 to emit light. The DC signal line that transmits the bias current can be brought from the left side of the mounting hole 320 on the circuit board 300 by means of wire bonding. The laser 420 can emit light after receiving the bias current transmitted by the DC signal line, and after the high-frequency signal line is transmitted to the laser 420, the laser 420 modulates the high-frequency signal into the light beam, so that the laser 420 generates signal light.

[0153] The DC signal line that transmits the bias current can also be connected to the laser 420 from the upper and lower sides of the mounting hole 320, that is, the DC signal line connected to the laser 420 and the high-frequency signal line are located on different sides of the mounting hole 320. This not only avoids interference between the high-frequency signal and the DC signal, but also makes the routing of the DC signal shorter, avoiding excessive congestion in the wiring of the circuit board 300.

[0154] Fig.23 Schematic diagram of the heat dissipation channel of the optical module provided in the embodiment of the present application. Fig.23As shown, after the light emitting submodule 400 is reversely installed on the front side of the circuit board 300, the bottom surface of the emitting base 410 in the light emitting submodule 400 faces the upper shell 201; after the laser 420 in the light emitting submodule 400 is connected to the DSP chip 310 on the front side of the circuit board 300 through the high-frequency signal line, the laser 420 generates a laser beam driven by the DC and high-frequency signals transmitted by the circuit board 300, so that the laser 420 generates heat, and the light-emitting performance of the laser 420 is affected by the temperature, so the laser 420 needs to work within a certain fixed temperature range, so the laser 420 needs to be placed on the semiconductor refrigerator 480 to ensure the working temperature of the laser 420, and the semiconductor refrigerator 480 generates a lot of heat during the cooling process, and the heat needs to be dissipated to ensure the cooling efficiency of the semiconductor refrigerator 480.

[0155] Since the laser 420 is fixed on the semiconductor cooler 480 on the transmitting base 410, the heat generated by the laser 420 will be transmitted to the transmitting base 410 through the semiconductor cooler 480 to maintain the temperature of the laser 420. In order to improve the heat dissipation performance of the optical module, the transmitting base 410 can be made of tungsten copper or other metal materials with good thermal conductivity, and the mass of the transmitting base 410 and the area of ​​the bottom are appropriately increased, so that the heat generated by the laser 420 and the semiconductor cooler 480 can be transmitted to the upper shell 201 through the transmitting base 410, effectively improving the heat dissipation effect of the laser 420.

[0156] In the embodiment of the present application, the mounting surface at one end of the transmitting base 410 is arranged corresponding to the mounting hole 320 of the circuit board 300, and there is a cavity between the mounting surface at the other end of the transmitting base 410 and the front of the circuit board 300 to install the related optical components of the optical transmitting sub-module 400. The laser 420 is arranged on the mounting surface corresponding to the mounting hole 320 through the semiconductor cooler 480, so that the mounting area of ​​the laser 420 on the transmitting base 410 is smaller than the contact area between the transmitting base 410 and the upper housing 201, which can improve the heat dissipation efficiency of the laser 420.

[0157] In order to ensure that the laser operates at a certain fixed temperature, the present application increases the mass of the transmitting base 410 and the contact area between the transmitting base 410 and the upper shell 201, so that the contact area between the transmitting base 410 and the upper shell 201 is larger than the installation area of ​​the laser 420 on the transmitting base 410. In this way, the heat generated by the laser 420 is transmitted to the laser substrate, the laser substrate transmits the heat to the semiconductor cooler 480, the semiconductor cooler 480 transmits the heat to the transmitting base 410, and the transmitting base 410 transmits the heat to the upper shell 201, thereby transmitting the heat generated by the laser 420 to the outside of the optical module.

[0158] In order to facilitate the transfer of heat from the launch base 410 to the upper shell 201, a first thermally conductive pad can be provided between the bottom of the launch base 410 and the inner side of the upper shell 201, so that the heat of the launch base 410 is transferred to the first thermally conductive pad, and the first thermally conductive pad transfers the heat to the upper shell 201, so as to effectively improve the heat dissipation effect. In the embodiment of the present application, the first thermally conductive pad can be a thermally conductive adhesive, which can not only adhere the launch base 410 to the inner side of the upper shell 201 through the thermally conductive adhesive, but also conduct the heat of the launch base 410 to the upper shell 201.

[0159] In the embodiment of the present application, in addition to the laser 420 and the semiconductor cooler 480, the main heat source of the optical module is the DSP chip 310. The side of the DSP chip 310 facing away from the circuit board 300 is in contact with the upper shell 201, so that the heat generated by the DSP chip 310 is transferred to the upper shell 201 to transfer the heat generated by the DSP chip 310 to the outside of the optical module.

[0160] To facilitate the transfer of heat from the DSP chip 310 to the upper shell 201, a second thermally conductive gasket can be set between the DSP chip 310 and the inner side of the upper shell 201, so that the heat generated by the DSP chip 310 is transferred to the second thermally conductive gasket, and the second thermally conductive gasket transfers the heat to the upper shell 201, thereby effectively improving the heat dissipation effect.

[0161] Fig.24 A cross-sectional view of the monitoring optical path of the optical detector in the optical module provided in the embodiment of the present application, Fig.25 A side view of the monitoring optical path of the optical detector in the optical module provided in the embodiment of the present application. Fig.24 , Fig.25 As shown, the laser 420 emits a laser beam driven by the bias current and high-frequency signal transmitted by the circuit board 300. In order to monitor the emitted light power of the laser 420, a light detector 350 is arranged on the back of the circuit board 300. The light detector 350 is arranged on the left edge of the mounting hole 320 on the circuit board 300, and the photosensitive surface of the light detector 350 faces the light emitting direction of the laser 420. It is used to collect the forward light emitted by the laser 420 and send the collected data to the relevant devices on the circuit board 300 to realize the monitoring of the forward light output power of the laser 420.

[0162] When the light detector 350 is mounted on the left side of the mounting hole 320, the photosensitive surface of the light detector 350 can be flush with the inner wall of the mounting hole 320 to facilitate the positioning of the light detector 350; the photosensitive surface of the light detector 350 can also be protruded from the inner wall of the mounting hole 320 to reduce the distance between the photosensitive surface of the light detector 350 and the first reflector 4410, so that the light detector 350 can collect as much laser light beam as possible passing through the first reflector 4410.

[0163] In the embodiment of the present application, the light transmittance characteristics of the reflective surface of the first reflector 4410 of the translation prism 440 are utilized to allow a small portion of the collimated light beam to leak through the first reflector 4410 and be incident on the photosensitive surface of the light detector 350, so that the light detector 350 can receive part of the light beam, thereby obtaining the emission light power of the laser 420.

[0164] Specifically, the first reflector 4410 of the translation prism 440 is directed toward the light emitting direction of the laser 420, and is used to split the laser light beam generated by the laser into two light beams. One light beam (usually accounting for 95% of the total power) is reflected by the first reflector 4410 to the second reflector 4420, so as to reflect the laser light beam from the back side of the circuit board 300 to the front side of the circuit board 300, and the other light beam is directly transmitted through the first reflector 4410 into the photosensitive surface of the light detector 350, and the laser light beam emitted by the light emitting surface of the laser 420 is received through the photosensitive surface.

[0165] When the light detector 350 is set on the back side of the circuit board 300, the central axis of the photosensitive surface in the light detector 350 can be coincident with the central axis of the laser 420, and the side of the light detector 350 facing the back side of the circuit board 300 is installed on the back side of the circuit board 300 through surface mounting technology (SMT), so that the light beam passing through the first reflector 4410 can be injected into the light detector 350 as much as possible.

[0166] In the embodiment of the present application, eight light detectors 350 are arranged on the back side of the circuit board 300, and each light detector 350 is arranged corresponding to each laser 420, so that each light detector 350 collects a portion of the laser light beam emitted by each laser 420 passing through the first reflector 4410, and measures the forward light output power of the corresponding laser 420 through a device electrically connected to the light detector 350.

[0167] Since the light detector 350 receives parallel light of a certain area, the assembly position accuracy requirement of the light detector 350 is low, and the assembly is easier. It is only necessary to align the light transmittance range of the first reflector 4410 in the translation prism 440 with the photosensitive surface of the light detector 350, so that the light detector 350 can collect the laser light beam passing through the first reflector 4410.

[0168] When the photodetector 350 is fixed on the back side of the circuit board 300, an anode is arranged on the side of the photodetector 350 connected to the back side of the circuit board 300, and the anode can be directly welded or conductively fixed to the ground metal layer on the circuit board 300 by conductive adhesive or the like; a cathode is arranged on the side of the photodetector 350 facing away from the back side of the circuit board 300, and the cathode is electrically connected to the circuit board 300 by wiring, thereby realizing the electrical connection between the photodetector 350 and the circuit board 300.

[0169] Fig.26 This is a schematic diagram of the assembly of the circuit board and the light receiving submodule in the optical module provided in the embodiment of the present application. Fig.26 As shown, for the 800G optical module, the optical module provided in the embodiment of the present application includes two optical receiving submodules, and the first optical receiving submodule 500 and the second optical receiving submodule 600 can be symmetrically arranged on both sides of the mounting hole 320 on the circuit board 300, that is, the first optical receiving submodule 500 is arranged on the front side of the mounting hole 320 on the circuit board 300, and the second optical receiving submodule 600 is arranged on the rear side of the mounting hole 320 on the circuit board 300. The first optical receiving submodule 500 is connected to the second optical fiber adapter 800 through the internal optical fiber, so that the external light beam received by the second optical fiber adapter 800 is transmitted to the first optical receiving submodule 500 through the internal optical fiber to achieve the reception of one composite light beam; the second optical receiving submodule 600 is connected to the third optical fiber adapter 900 through the internal optical fiber, so that the external light beam received by the third optical fiber adapter 900 is transmitted to the second optical receiving submodule 600 through the internal optical fiber to achieve the reception of another composite light beam.

[0170] Fig. 27 This is a schematic diagram of the structure of the optical part of the optical receiving submodule in the optical module provided in the embodiment of the present application. Fig.28 This is a cross-sectional view of the receiving light path in the optical module provided in the embodiment of the present application. Fig. 27 , Fig.28 As shown, the first optical receiving submodule 500 has the same structure as the second optical receiving submodule 600. The second optical receiving submodule 600 includes a support plate 650 and an optical collimator 610, an optical splitter 620, a lens array 630 and a reflecting prism 640 arranged on the support plate 650. The internal optical fiber connected to the third optical fiber adapter 900 is inserted into the optical collimator 610, and the external optical signal is transmitted to the optical splitter 620 through the optical collimator 610. Then, one composite light beam is demultiplexed into four light beams through the optical splitter 620. The four light beams are respectively converged to the reflecting prism 640 through the lens array 630. The light beams are reflected at the reflecting surface of the reflecting prism 640, and the light beam parallel to the front of the circuit board 300 is reflected as a light beam perpendicular to the front of the circuit board 300, and the reflected light beam is projected into the detector 360 on the circuit board 300 to achieve light reception.

[0171] The optical collimator 610 includes a second single-mode fiber flange 6110 and a collimator 6120. The internal optical fiber is inserted into the optical collimator 610 through the second single-mode fiber flange 6110. The collimator 6120 is arranged on the light-emitting surface of the internal optical fiber, and is used to convert the external light beam transmitted by the internal optical fiber into a collimated light beam. The light-incoming surface of the optical splitter 620 faces the light-emitting surface of the collimator 6120, and is used to demultiplex one collimated light beam output by the optical collimator 610 into four light beams, and separate the light beams containing multiple different wavelengths. The optical splitter 620 outputs four light beams with different wavelengths, and the four light beams with different wavelengths are respectively incident on the corresponding lenses of the lens array 630 to converge the light beams onto the reflection surface of the reflection prism 640. The reflection prism 640 is arranged directly above the detector 360 on the circuit board 300 to reflect the four light beams transmitted to the reflection prism 640 into the corresponding detectors 360, and convert the optical signal into an electrical signal through the detector 360.

[0172] The DSP chip 310 on the circuit board 300 is connected to the detector 360 set on the front side of the circuit board 300 through a signal line. The high-frequency current signal received by the detector 360 is first transmitted to a transimpedance amplifier (TIA) to be converted into a high-frequency voltage signal and amplified, and then transmitted to the DSP chip 310 via a high-frequency signal line for processing, and then transmitted to the communication system via a gold finger, which is beneficial to the installation, coupling and circuit connection of the optical components required for the receiving signal of the optical receiving submodule.

[0173] In the embodiment of the present application, a transimpedance amplifier may also be provided on the circuit board 300, one end of the transimpedance amplifier is connected to the detector 360 through a signal line, and the other end is connected to the DSP chip 310 through a signal line. The high-frequency signal received by the detector 360 is converted into a voltage signal and amplified by the transimpedance amplifier, and then transmitted to the DSP chip 310 for processing via the high-frequency signal line connecting the transimpedance amplifier and the DSP chip 310. After being processed by the DSP chip 310, the high-frequency signal is transmitted to the communication system via the gold finger.

[0174] In the embodiment of the present application, the optical part of the optical receiving submodule may also use an optical wave splitting device based on AWG technology to achieve the same optical wave splitting and coupling effects.

[0175] The first light receiving submodule 500 and the second light receiving submodule 600 are installed in the same manner, and the installation manner of the second light receiving submodule 600 is taken as an example for description. Since there is a height difference between the optical collimator 610, the optical splitter 620, the lens array 630, the reflective prism 640 in the second light receiving submodule 600 and the detector 360 on the circuit board 300, in order to ensure the height difference of signal transmission, the first light receiving submodule 500 and the second light receiving submodule 600 are fixedly installed on the circuit board 300.

[0176] Specifically, the optical collimator 610, the optical splitter 620, the lens array 630 and the reflective prism 640 are fixedly mounted on the support plate 650 according to the light receiving direction to be assembled into a pre-assembled component. When assembling the light receiving sub-module, the pre-assembled component is directly coupled and assembled and fixed on the circuit board 300, thereby ensuring that the reflective prism 640 in the pre-assembled component couples the multi-path optical signals into the detector 360 located on the circuit board 300.

[0177] After the second light receiving sub-module 600 is fixed on the circuit board 300, there is a gap between the support plate 650 of the second light receiving sub-module 600 and the circuit board 300, which will be filled with special glue, thereby ensuring the installation height difference between the optical collimator 610, the optical splitter 620, the lens array 630, the reflective prism 640 and the detector 360 on the circuit board 300.

[0178] After the optical transmitting submodule 400, the first optical receiving submodule 500 and the second optical receiving submodule 600 are mounted on the front of the circuit board 300, four optical fiber adapters are provided at the optical interface where the upper shell 201 and the lower shell 202 are assembled. The optical transmitting submodule 400 is connected to the first optical fiber adapter group 700 (including the first optical fiber adapter 710 and the fourth optical fiber adapter 720, and the first optical fiber adapter 710 and the fourth optical fiber adapter 720 are arranged adjacent to each other) through two internal optical fibers to achieve the emission of two composite light beams; the first optical receiving submodule 500 is connected to the second optical fiber adapter 800 through the internal optical fiber to achieve the reception of one composite light beam; the second optical receiving submodule 600 is connected to the third optical fiber adapter 900 through the internal optical fiber to achieve the reception of another composite light beam. In this way, the optical port where the upper shell 201 and the lower shell 202 are assembled has four optical interfaces to accommodate the first optical fiber adapter 710, the second optical fiber adapter 800, the third optical fiber adapter 900 and the fourth optical fiber adapter 720.

[0179] In the embodiment of the present application, the first optical receiving submodule 500 and the second optical receiving submodule 600 are installed on the front side of the circuit board 300 in a symmetrical structure, forming a complementary structure in the layout of the optical module, avoiding position conflicts between the components, making the overall structure compact and easy to install.

[0180] Fig.29 Schematic diagram of the assembly of the circuit board, optical transmitting submodule, optical receiving submodule and optical fiber adapter in the optical module provided in the embodiment of the present application Figure 2 , Fig.30 This is a schematic diagram of the assembly of the circuit board, the optical receiving sub-module and the optical fiber adapter in the optical module provided in the embodiment of the present application. Fig.29 , Fig.30As shown, in order to reduce the width dimension of the circuit board 300, the optical transmitting submodule 400 can also be reversely assembled on the front side of the circuit board 300, and the first optical receiving submodule 500 can be installed on the front side of the circuit board 300 and located on one side of the optical transmitting submodule 400; the second optical receiving submodule 600 can be installed on the back side of the circuit board 300, and the first optical receiving submodule 500 and the second optical receiving submodule 600 can be symmetrically arranged.

[0181] The second optical fiber adapter group connected to the first optical receiving sub-module 500 and the second optical receiving sub-module 600 is composed of two adjacent optical fiber adapters 810 and 820, and the two optical fiber adapters 810 and 820 are arranged in parallel along the up and down directions of the transmitting base 410, that is, one optical fiber adapter 810 is connected to the first optical receiving sub-module 500 through an internal optical fiber to achieve the reception of one composite light beam; the other optical fiber adapter 820 is connected to the second optical receiving sub-module 600 through another internal optical fiber to achieve the reception of another composite light beam.

[0182] Since the first optical receiving submodule 500 and the second optical receiving submodule 600 are symmetrically arranged on the front and back sides of the circuit board 300, the two optical interfaces of the second optical fiber adapter group are arranged up and down to form a complementary structure in the layout of the optical module, avoiding position conflicts between the components, making the overall structure compact and easy to install.

[0183] Fig.31 This is a partial assembly cross-sectional view of the circuit board and the light receiving sub-module in the optical module provided in the embodiment of the present application. Fig.31 As shown, the first optical receiving submodule 500 and the second optical receiving submodule 600 are symmetrically arranged on the front and back sides of the circuit board 300. The first optical receiving submodule 500 arranged on the front side of the circuit board 300 is connected to an optical interface of the second optical fiber adapter group through an internal optical fiber, so that the external light beam is transmitted to the first optical receiving submodule 500 through the internal optical fiber, and one composite light beam is demultiplexed into four light beams through an optical splitter. The four light beams are reflected from the horizontal direction to the downward transmission through a reflecting prism to be transmitted to the detector 360 arranged on the front side of the circuit board 300, and the optical signal is converted into an electrical signal through the detector 360, and the electrical signal is transmitted to the transimpedance amplifier 370 arranged on the front side of the circuit board 300. The electrical signal is amplified by the transimpedance amplifier 370 and then transmitted to the DSP chip 310, and then the amplified electrical signal is processed by the DSP chip 310.

[0184] The second optical receiving submodule 600 arranged on the back side of the circuit board 300 is connected to another optical interface of the second optical fiber adapter group through the internal optical fiber, so that the external light beam is transmitted to the second optical receiving submodule 600 through the internal optical fiber, and one composite light beam is demultiplexed into four light beams through the optical splitter, and the four light beams are reflected from the horizontal direction to the upward transmission through the reflecting prism to be transmitted to the detector arranged on the back side of the circuit board 300, and the optical signal is converted into an electrical signal through the detector, and the electrical signal is transmitted to the transimpedance amplifier arranged on the back side of the circuit board 300, and the electrical signal is amplified by the transimpedance amplifier and transmitted to the DSP chip 310 arranged on the front side of the circuit board 300, and then the amplified electrical signal is processed by the DSP chip 310.

[0185] In the embodiment of the present application, after the second optical receiving sub-module 600 is set on the back side of the circuit board 300, a via is set under the Rx input pad of the DSP chip 310, and the via passes through the front and back sides of the circuit board 300. The high-frequency signal line connected to the Rx input pad of the DSP chip 310 passes through the via on the circuit board 300 to the back side of the circuit board 300, and is connected to the transimpedance amplifier on the back side of the circuit board 300 through the high-frequency signal line, so as to transmit the high-frequency signal on the circuit board 300 from the front side of the circuit board 300 to the back side, so that the high-frequency signal is transmitted to the transimpedance amplifier located on the back side of the circuit board 300, thereby realizing the wiring connection between the second optical receiving sub-module 600 and the circuit board 300.

[0186] The optical module provided in the embodiment of the present application adopts a single-chip circuit board to simplify the installation difficulty; the optical path translation is used to reduce the hole area of ​​the circuit board, which is easier to layout; the integrated optical emission components, such as optical combiners, optical isolators, optical fiber couplers, etc., are used to simplify light alignment, coupling and other assembly difficulties; the optical emission sub-module adopts a bottom-up (flip-chip) assembly structure to reduce the overall geometric size of the optical emission sub-module and greatly improve the heat dissipation characteristics of the optical emission sub-module; the laser of the optical emission sub-module adopts a new spacing setting to greatly reduce the spacing between the lasers and the width of the optical emission sub-module, and the laser, collimating lens and translation prism of the optical emission sub-module are placed on the back side of the circuit board through the mounting holes on the circuit board to ensure that the high-frequency transmission line length is the shortest; the independent optical emission sub-module structure is used to facilitate production and maintenance; the innovative optical power detection design is used to realize the direct detection of the forward light output power of the laser, and the detection value is more real and accurate.

[0187] The optical module provided in the present application achieves high-frequency signal integrity while maximally improving the heat dissipation effect of the optical transmission submodule through a unique structural design and arrangement, and greatly reduces the number of optical components and the assembly workload by adopting integrated optical components, that is, the high-frequency performance, optical performance, heat dissipation characteristics, structural complexity, manufacturability and other functions required for a high-transmission rate optical module are achieved in a small space. By adopting a special structural design and a reasonable assembly process, the overall assembly of the module is greatly simplified, the production efficiency and maintenance efficiency are greatly improved, and it is more suitable for mass production.

[0188] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An optical module, characterized in that: include: A circuit board having mounting holes disposed thereon; An optical transmission submodule, electrically connected to the circuit board, and configured to transmit an optical signal; An optical fiber adapter connected to the optical transmission submodule; Wherein, the optical emission sub-module comprises: The transmitting base comprises a first mounting surface, a second mounting surface and a third mounting surface facing the circuit board, wherein the first mounting surface is recessed in the second mounting surface, and the second mounting surface is recessed in the third mounting surface; the width dimension of the third mounting surface in the front-to-back direction is greater than the width dimension of the first mounting surface in the front-to-back direction; the second mounting surface and the third mounting surface are respectively located above the mounting hole; A laser, arranged on the third mounting surface, located on the back side of the circuit board through the mounting hole, and used for emitting a laser beam; A translation prism is arranged on the second mounting surface, one end of which is located on the back side of the circuit board through the mounting hole, and the other end is located on the front side of the circuit board, and is used to reflect the laser beam located on the back side of the circuit board to the front side of the circuit board; The optical fiber coupler is arranged on the first mounting surface and is located between the front side of the circuit board and the first mounting surface, and is used for coupling the laser beam reflected by the translation prism to the optical fiber adapter.

2. The optical module according to claim 1, characterized in that: The optical transmission submodule further comprises: A plurality of lasers are arranged side by side on the third mounting surface along the front-to-back direction, and are used to emit a plurality of laser beams with different wavelengths; A first optical combiner, disposed on the first mounting surface, for multiplexing the multiple laser beams reflected by the translation prism into a composite beam; A second optical combiner, arranged side by side with the first optical combiner on the first mounting surface, for multiplexing the remaining multiple laser beams reflected by the translation prism into another composite beam; A first optical fiber coupler, coupled to the first optical combiner, and used for coupling one path of the composite light beam to the optical fiber adapter; The second optical fiber coupler is coupled to the second optical combiner and is used to couple another path of the composite light beam to the optical fiber adapter.

3. The optical module according to claim 2, characterized in that: The width dimensions of the first optical combiner and the second optical combiner in the front-to-back direction are greater than the width dimension of the first mounting surface in the front-to-back direction.

4. The optical module according to claim 1, characterized in that: A positioning block is provided at one end of the transmitting base facing away from the optical fiber adapter. The positioning block protrudes from the third mounting surface toward the side of the circuit board and contacts and connects with the front side of the circuit board toward the side of the circuit board.

5. The optical module according to claim 4, characterized in that: Two supporting columns are symmetrically arranged on one end of the first mounting surface facing the optical fiber adapter, and the supporting columns are in contact and connected with the front surface of the circuit board facing the side surface of the circuit board.

6. The optical module according to claim 5, characterized in that: An opening is provided between the two support columns, and the optical fiber connected to the optical fiber coupler passes through the opening and is connected to the optical fiber adapter; The width of the two support columns in the front-to-rear direction is not greater than the width of the first mounting surface in the front-to-rear direction.

7. The optical module according to claim 6, characterized in that: The support column and the positioning block are both provided with positioning pins, and the circuit board is provided with corresponding positioning holes, and the positioning pins are inserted into the positioning holes.

8. The optical module according to claim 1, characterized in that: A first supporting block is disposed at one end of the first mounting surface facing the optical fiber adapter. A through hole is disposed on the first supporting block. The through hole is communicated with the first mounting surface, and the optical fiber coupler is inserted into the through hole.

9. The optical module according to claim 8, characterized in that: The width dimension of the first supporting block in the front-to-rear direction is not greater than the width dimension of the first mounting surface in the front-to-rear direction.

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