An optical module

Abstract

The application discloses an optical module comprising a light transceiver assembly. The light transceiver assembly comprises a transceiver shell and a third circuit board. The transceiver shell is provided with a light window at a first end, an insertion opening for the third circuit board at a second end, and an optical assembly inside. The third circuit board is provided with a hollowed-out area. The optical assembly comprises a laser chip, a first lens, a lithium niobate chip, a second lens, a second filter, a third lens, a receiving turning prism and a light receiving chip. The laser chip, the first lens, the second lens, the second filter, the receiving turning prism, the third lens and the light receiving chip are located at the first end of the transceiver shell, and the lithium niobate chip is located at the second end of the transceiver shell. The lithium niobate chip is arranged in correspondence with the hollowed-out area. In the application, the laser chip provides high-power light, and the light loss of the lithium niobate chip is less than that of a silicon light chip, so that the modulated light signal modulated by the lithium niobate chip meets the light power requirement of 50GPON emission light.

Description

Technical Field

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

[0002] The international standard for 50G GPON, ITU-T G.9804.3, was released in September 2021. To maintain the current PON link budget of 29dB / 32dB, the 50G PON standard imposes higher requirements on the optical power transmitted by the OLT optical module. The current conventional 53GBaud EML cannot meet the optical power requirements of 50G PON.

[0003] To meet the optical power requirements of the 50G PON standard for OLT optical modules, many major international manufacturers have been developing EML+SOA chip solutions for 50G PON. However, these manufacturers are currently facing significant technical challenges, and no EML+SOA optical devices for 50G PON OLTs have yet been released. Therefore, no single optical module can currently meet the optical power requirements of 50G PON. Summary of the Invention

[0004] This application provides an optical module that meets the optical power requirements of 50G PON transmitted light.

[0005] An optical module, comprising:

[0006] Optical transceiver assembly, including transceiver housing and third circuit board;

[0007] The transceiver housing has a light window at the first end for emitting or receiving light signals, an insertion port at the second end for inserting a third circuit board, and an optical component inside.

[0008] The third circuit board has a cut-out area;

[0009] Optical components include a laser chip, a first lens, a lithium niobate chip, a second lens, a second filter, a third lens, a receiving prism, and a light receiving chip.

[0010] The laser chip, first lens, second lens, second filter, receiving prism, third lens and optical receiving chip are all located at the first end of the transceiver housing, and the lithium niobate chip is located at the second end of the transceiver housing;

[0011] The first lens is located between the laser chip and the lithium niobate chip;

[0012] The lithium niobate chip, corresponding to the hollowed-out area, includes a substrate and a lithium niobate thin film, with an optical loss of less than 10dB;

[0013] A lithium niobate thin film, deposited on a substrate, with a thickness of less than 100 μm;

[0014] The second lens is located between the lithium niobate chip and the second filter;

[0015] The second filter is located between the laser chip and the third lens;

[0016] The receiving deflection prism is located above the optical receiving chip.

[0017] Beneficial Effects: This application provides an optical module, including an optical transceiver assembly. The optical transceiver assembly includes a transceiver housing and a third circuit board. The transceiver housing has a first end with an optical window for optical signals to exit or enter, and a second end with an insertion port for the third circuit board. Optical components are housed inside. The third circuit board has a cut-out area. A first optical signal in the transceiver housing exits through the optical window, and a second optical signal from the fiber optic adapter enters the transceiver housing through the optical window. The circuit board is inserted into the transceiver housing through the insertion port. To ensure a tight seal between the circuit board and the transceiver housing, copper foil is laid on the area of ​​the circuit board corresponding to the insertion port. The transceiver housing is a metal transceiver housing, and the circuit board is soldered to the insertion port of the transceiver housing to ensure a tight seal between the circuit board and the transceiver housing. The optical components include a laser chip, a first lens, a lithium niobate chip, a second lens, a second filter, a third lens, a receiving prism, and a light receiving chip. The laser chip, first lens, second lens, second filter, third lens, receiving prism, and light receiving chip are all located at the first end of the transceiver housing, and the lithium niobate chip is located at the second end of the transceiver housing. The laser chip is a high-power DFB laser chip. The high-power DFB laser chip is used to emit high-power light. A first lens, located between the laser chip and the lithium niobate chip, is used to couple the high-power light to the lithium niobate chip. The lithium niobate chip, corresponding to the cut-out area, includes a substrate and a lithium niobate thin film, with an optical loss of less than 10dB, and is used to modulate the high-power light to obtain a modulated optical signal. The lithium niobate thin film is deposited on the substrate and has a thickness of less than 100μm. Due to the smaller size and higher integration precision of the lithium niobate chip, it has advantages such as lower power consumption and lower optical loss compared to silicon photonics chips. Specifically, the optical loss of the silicon photonics chip is less than 11.2dB, and the optical loss of the lithium niobate chip is less than 10dB. Because the optical loss of the silicon photonics chip is less than 11.2dB, in order for the optical module including the DFB laser chip + silicon photonics chip combination to meet the optical power requirements of 50G PON, the optical power emitted by the DFB laser chip must be >158mW. Because the optical loss of lithium niobate chips is less than 10dB, to ensure that the optical module combining a DFB laser chip and a lithium niobate chip meets the optical power requirements for 50G PON, the optical power emitted by the DFB laser chip must be greater than 80mW. Conventional DFB laser chips emit optical power less than 50mW, and high-power DFB laser chips emit optical power less than 120mW. Currently, it is difficult for DFB laser chips to achieve an optical power exceeding 120mW across the entire temperature range. Therefore, to meet the optical power requirements for 50G PON, the optical module must use a combination of a DFB laser chip and a lithium niobate chip. A second lens, located between the lithium niobate chip and the second filter, is used to collimate the modulated optical signal to obtain a collimated optical signal. A second filter, located between the laser chip and the third lens, is used to transmit the collimated optical signal to the fiber optic adapter.A third lens, located between the second filter and the receiving deflection prism, couples the second optical signal reflected from the second filter to the receiving deflection prism. The receiving deflection prism, located above the optical receiving chip, modulates the second optical signal so that it is reflected back to the optical receiving chip. In this application, the laser chip provides high-power light, and the optical loss of the lithium niobate chip is less than that of the silicon photonics chip, ensuring that the modulated optical signal modulated by the lithium niobate chip meets the optical power requirements for 50G PON transmission. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a diagram showing the connection relationships of an optical communication system.

[0020] Figure 2 This is a structural diagram of an optical network terminal;

[0021] Figure 3 This is a structural diagram of an optical module according to some embodiments;

[0022] Figure 4 This is an exploded structural diagram of an optical module according to some embodiments;

[0023] Figure 5 This is a structural diagram of an optical module with the upper housing removed according to some embodiments;

[0024] Figure 6 This is a structural diagram of an optical transceiver assembly and circuit board according to some embodiments;

[0025] Figure 7 An exploded view of an optical transceiver assembly and circuit board according to some embodiments;

[0026] Figure 8 This is a first structural diagram of an optical transceiver assembly according to some embodiments;

[0027] Figure 9 This is a second structural diagram of an optical transceiver assembly according to some embodiments;

[0028] Figure 10 This is a first cross-sectional view of an optical transceiver assembly according to some embodiments;

[0029] Figure 11 This is a second cross-sectional view of an optical transceiver assembly according to some embodiments;

[0030] Figure 12 This is a third cross-sectional view of an optical transceiver assembly according to some embodiments;

[0031] Figure 13 An exploded view of an optical transceiver assembly according to some embodiments;

[0032] Figure 14 This is a structural diagram of an optical transceiver assembly with the top cover removed, according to some embodiments;

[0033] Figure 15 This is a structural diagram of an optical component and a third circuit board according to some embodiments;

[0034] Figure 16 This is a structural diagram of an optical component according to some embodiments;

[0035] Figure 17 This is a structural diagram of a third circuit board according to some embodiments;

[0036] Figure 18 This is a structural diagram of an optical fiber adapter, focusing ring, fourth lens, and lens mount according to some embodiments;

[0037] Figure 19 An exploded view of an optical fiber adapter, adjustment ring, fourth lens, and lens mount according to some embodiments;

[0038] Figure 20 This is a first structural diagram of a transceiver socket according to some embodiments;

[0039] Figure 21 This is a second structural diagram of a transceiver socket according to some embodiments;

[0040] Figure 22 This is a third structural diagram of a transceiver socket according to some embodiments;

[0041] Figure 23 This is an exploded view of a transceiver connector according to some embodiments;

[0042] Figure 24 This is a first cross-sectional view of a transceiver socket according to some embodiments;

[0043] Figure 25 This is a second cross-sectional view of a transceiver socket according to some embodiments;

[0044] Figure 26 This is a first optical path diagram of an optical module according to some embodiments;

[0045] Figure 27 This is a second optical path diagram of an optical module according to some embodiments. Detailed Implementation

[0046] In optical communication systems, optical signals carry the information to be transmitted and are transmitted through information transmission equipment such as optical fibers or waveguides to information processing equipment such as computers to complete the information transmission. Because light has passive transmission characteristics when transmitted through optical fibers or waveguides, low-cost, low-light-loss information transmission can be achieved. However, the signals transmitted by information transmission equipment such as optical fibers or waveguides are optical signals, while the signals that information processing equipment such as computers can recognize and process are electrical signals. Therefore, in order to establish an information connection between information transmission equipment such as optical fibers or waveguides and information processing equipment such as computers, it is necessary to achieve mutual conversion between electrical and optical signals.

[0047] In the field of optical communication technology, optical modules realize the mutual conversion function between optical signals and electrical signals. An optical module includes an optical port and an electrical port. The optical port enables optical communication with information transmission devices such as optical fibers or optical waveguides, while the electrical port enables electrical connection with optical network terminals (e.g., optical modems). The electrical connection is mainly used for power supply, I2C signal transmission, data transmission, and grounding. The optical network terminal transmits electrical signals to information processing devices such as computers via network cables or Wi-Fi.

[0048] Figure 1 This is a diagram showing the connection relationships within an optical communication system. (Example:) Figure 1 As shown, the optical communication system includes a remote server 1000, a local information processing device 2000, an optical network terminal 100, an optical module 200, an optical fiber 101, and a network cable 103.

[0049] One end of optical fiber 101 is connected to the remote server 1000, and the other end is connected to the optical network terminal 100 via optical module 200. Optical fiber itself can support long-distance signal transmission, such as signal transmission over several kilometers (6 to 8 kilometers). Theoretically, unlimited distance transmission can be achieved by using repeaters. Therefore, in typical optical communication systems, the distance between the remote server 1000 and the optical network terminal 100 can typically reach several kilometers, tens of kilometers, or hundreds of kilometers.

[0050] One end of the network cable 103 is connected to the local information processing device 2000, and the other end is connected to the optical network terminal 100. The local information processing device 2000 can be any one or more of the following devices: router, switch, computer, mobile phone, tablet computer, television, etc.

[0051] The physical distance between the remote server 1000 and the optical network terminal 100 is greater than the physical distance between the local information processing device 2000 and the optical network terminal 100. The connection between the local information processing device 2000 and the remote server 1000 is completed by optical fiber 101 and network cable 103; while the connection between optical fiber 101 and network cable 103 is completed by optical module 200 and optical network terminal 100.

[0052] The optical module 200 includes an optical port and an electrical port. The optical port is configured to connect to the optical fiber 101, thereby establishing a bidirectional optical signal connection between the optical module 200 and the optical fiber 101. The electrical port is configured to connect to the optical network terminal 100, thereby establishing a bidirectional electrical signal connection between the optical module 200 and the optical network terminal 100. The optical module 200 performs mutual conversion between optical and electrical signals, thereby establishing an information connection between the optical fiber 101 and the optical network terminal 100. For example, the optical signal from the optical fiber 101 is converted into an electrical signal by the optical module 200 and then input to 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 200 and then input to the optical fiber 101. Since the optical module 200 is a tool for mutual conversion between optical and electrical signals and does not have the function of data processing, the information does not change during the above photoelectric conversion process.

[0053] The optical network terminal 100 includes a generally cuboid housing, and an optical module interface 102 and a network cable interface 104 disposed on the housing. The optical module interface 102 is configured to connect to an optical module 200, thereby establishing a bidirectional electrical signal connection between the optical network terminal 100 and the optical module 200; the network cable interface 104 is configured to connect to a network cable 103, thereby establishing a bidirectional electrical signal connection between the optical network terminal 100 and the network cable 103. The optical module 200 and the network cable 103 are connected through the optical network terminal 100. For example, the optical network terminal 100 transmits electrical signals from the optical module 200 to the network cable 103, and vice versa, thus the optical network terminal 100 acts as a host computer for the optical module 200, monitoring its operation. Besides the optical network terminal 100, the host computer for the optical module 200 may also include an optical line terminal (OLT), etc.

[0054] The remote server 1000 establishes a bidirectional signal transmission channel with the local information processing equipment 2000 through optical fiber 101, optical module 200, optical network terminal 100 and network cable 103.

[0055] Figure 2 This is a structural diagram of an optical network terminal. To clearly show the connection relationship between the optical module 200 and the optical network terminal 100... Figure 2Only the structure of the optical network terminal 100 related to the optical module 200 is shown. For example... Figure 2 As shown, the optical network terminal 100 also includes a circuit board 105 disposed within a housing, a cage 106 disposed on the surface of the circuit board 105, a heat sink 107 disposed on the cage 106, and an electrical connector disposed inside the cage 106. The electrical connector is configured to connect to the electrical port of the optical module 200; the heat sink 107 has protrusions such as fins to increase the heat dissipation area.

[0056] The optical module 200 is inserted into the cage 106 of the optical network terminal 100, where it is secured. Heat generated by the optical module 200 is conducted to the cage 106 and then dissipated through the heat sink 107. After insertion into the cage 106, the optical module 200's electrical port connects to an electrical connector inside the cage 106, establishing a bidirectional electrical signal connection between the optical module 200 and the optical network terminal 100. Furthermore, the optical port of the optical module 200 connects to the optical fiber 101, establishing a bidirectional optical signal connection between the optical module 200 and the optical fiber 101.

[0057] Figure 3 This is a structural diagram of an optical module according to some embodiments. Figure 4 This is an exploded structural diagram of an optical module according to some embodiments. For example... Figure 3 and 4 As shown, the optical module 200 includes a shell, a circuit board 300 disposed inside the shell, and an optical transceiver assembly 400.

[0058] The housing includes an upper housing 201 and a lower housing 202, with the upper housing 201 covering the lower housing 202 to form the aforementioned housing with two openings; the outer contour of the housing is generally square.

[0059] In some embodiments of this disclosure, the lower housing 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and perpendicular to the base plate 2021; the upper housing 201 includes a cover plate 2011, which covers the two lower side plates 2022 of the lower housing 202 to form the aforementioned housing.

[0060] In some embodiments, the lower housing 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and perpendicular to the base plate 2021; the upper housing 201 includes a cover plate 2011 and two upper side plates located on both sides of the cover plate 2011 and perpendicular to the cover plate 2011. The two upper side plates and the two lower side plates 2022 are combined to realize that the upper housing 201 covers the lower housing 202.

[0061] The direction of the line connecting the two openings 204 and 205 can be consistent with or inconsistent with the length direction of the optical module 200. For example, opening 204 is located at the end of the optical module 200. Figure 3 The opening 205 is also located at the end of the optical module 200 (right end). Figure 3 (Left end). Alternatively, opening 204 is located at the end of optical module 200, while opening 205 is located on the side of optical module 200. Opening 204 is an electrical port, through which the gold fingers 301 of circuit board 300 extend and are inserted into a host computer (e.g., optical network terminal 100); opening 205 is an optical port, configured to connect to external optical fiber 101 so that external optical fiber 101 can connect to the optical transceiver assembly 400 inside optical module 200.

[0062] The assembly method using an upper housing 201 and a lower housing 202 facilitates the installation of components such as the circuit board 300 and the optical transceiver assembly 400 into the housing, with the upper housing 201 and lower housing 202 providing encapsulation and protection for these components. Furthermore, the assembly of the circuit board 300 and the optical transceiver assembly 400 facilitates the deployment of positioning components, heat dissipation components, and electromagnetic shielding components, which is beneficial for automated production.

[0063] In some embodiments, the upper housing 201 and the lower housing 202 are generally made of metal materials, which facilitates electromagnetic shielding and heat dissipation.

[0064] In some embodiments, the optical module 200 further includes an unlocking component located outside its housing, the unlocking component being configured to establish a fixed connection between the optical module 200 and the host computer, or to release the fixed connection between the optical module 200 and the host computer.

[0065] For example, the unlocking component is located on the outer wall of the two lower side plates 2022 of the lower housing 202, and has a locking component that matches the host computer cage (e.g., the cage 106 of the optical network terminal 100). When the optical module 200 is inserted into the host computer cage, the locking component of the unlocking component fixes the optical module 200 in the host computer cage; when the unlocking component is pulled, 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 200 and the host computer, thereby allowing the optical module 200 to be pulled out of the host computer cage.

[0066] Circuit board 300 includes circuit traces, electronic components, and chips. The circuit traces connect the electronic components and chips according to the circuit design to achieve functions such as power supply, electrical signal transmission, and grounding. Electronic components include, for example, capacitors, resistors, transistors, and metal-oxide-semiconductor field-effect transistors (MOSFETs). Chips include, for example, microcontroller units (MCUs), laser driver chips, limiting amplifiers, clock and data recovery (CDR) chips, power management chips, and digital signal processing (DSP) chips.

[0067] Circuit board 300 is generally a rigid circuit board. Due to its relatively rigid material, the rigid circuit board can also perform a load-bearing function. For example, the rigid circuit board can stably support the aforementioned electronic components and chips. When the optical transceiver assembly is located on the circuit board, the rigid circuit board can also provide stable support. The rigid circuit board can also be inserted into the electrical connector in the host computer cage.

[0068] The circuit board 300 also includes gold fingers 301 formed on its end surface, the gold fingers 301 consisting of a plurality of independent pins. The circuit board 300 is inserted into the cage 106 and is electrically connected to an electrical connector within the cage 106 by the gold fingers 301. The gold fingers 301 may be provided only on one side of the surface of the circuit board 300 (e.g., Figure 4 The gold fingers 301 (shown on the upper surface) can also be placed on the upper and lower surfaces of the circuit board 300 to accommodate applications with a large number of pins. The gold fingers 301 are configured to establish an electrical connection with the host computer to enable power supply, grounding, I2C signal transmission, and data signal transmission.

[0069] Of course, flexible circuit boards are also used in some optical modules. Flexible circuit boards are generally used in conjunction with rigid circuit boards as a supplement to rigid circuit boards. For example, flexible circuit boards can be used to connect rigid circuit boards to optical transceiver components.

[0070] Optical transceiver unit 400 is used to transmit and receive optical signals.

[0071] Figure 5 This is a structural diagram of an optical module with the upper housing removed, according to some embodiments. Figure 6 This is a structural diagram of an optical transceiver assembly and circuit board according to some embodiments. Figure 7 This is an exploded view of an optical transceiver assembly and circuit board according to some embodiments. Figure 4-7As can be seen, in some embodiments, the circuit board 300 includes a first circuit board 301 and a second circuit board 302, with the first circuit board 301 connected to the second circuit board 302. The first circuit board 301 is a rigid circuit board, with its first end connected to the second end of the second circuit board 302, and the second end having gold fingers. The second circuit board 302 is a flexible circuit board, with its first end connected to the optical transceiver assembly 400, and its second end connected to the first end of the first circuit board 301.

[0072] Figure 8 This is a first structural diagram of an optical transceiver assembly according to some embodiments. Figure 9 This is a second structural diagram of an optical transceiver assembly according to some embodiments. Figure 10 This is a first cross-sectional view of an optical transceiver assembly according to some embodiments. Figure 11 This is a second cross-sectional view of an optical transceiver assembly according to some embodiments. Figure 12 This is a third cross-sectional view of an optical transceiver assembly according to some embodiments. Figure 13 This is an exploded view of an optical transceiver assembly according to some embodiments. Figure 4-13 As can be seen, in some embodiments, the optical transceiver assembly 400 includes a transceiver housing 401, an optical fiber adapter 404, and a third circuit board 303. The transceiver housing 401 has a light window at its first end and an insertion port at its second end. The first end of the transceiver tube 401 is connected to a lens holder 405 via laser welding. The lens holder 405 is welded to the light window of the transceiver tube 401. The lens holder 405 is connected to the optical fiber adapter 404 via a focusing ring 406. The third circuit board 303 is inserted into the transceiver housing 401 through the insertion port.

[0073] Figure 14 This is a structural diagram of an optical transceiver assembly with the top cover removed, according to some embodiments. Figure 15 This is a structural diagram of an optical component and a third circuit board according to some embodiments. Figure 16 This is a structural diagram of an optical component according to some embodiments. For example... Figure 4-16As can be seen, in some embodiments, the transceiver housing 401 includes an upper cover 4011 and a transceiver socket 4012. The upper cover 4011 covers the transceiver socket 4012, and the upper cover 4011 and the transceiver socket 4012 form a hollow transceiver cavity. An optical assembly is disposed within this transceiver cavity. This optical assembly includes a laser chip 4021, a first lens 4022, an isolator 4023, a lithium niobate chip 4024, a second lens 4025, a second filter 4026, a third lens 4027, a receiving prism 40210, a light receiving chip 4028, and a transimpedance amplifier chip 40214. The laser chip 4021, first lens 4022, isolator 4023, lithium niobate chip 4024, second lens 4025, second filter 4026, third lens 4027, receiving prism 40210, and optical receiver chip 4028 are all located on the transceiver socket 4012, while the transimpedance amplifier chip 40214 is located on the third circuit board 303. Specifically,

[0074] The laser chip 4021 is used to emit high-power light. Specifically, since the laser chip 4021 is a high-power DFB laser chip, it can provide high-power light. The wavelength of the high-power light emitted by the laser chip 4021 is λ1, and the emitted high-power light is divergent.

[0075] Since the high-power light emitted by the laser chip 4021 is divergent, a first lens 4022 is provided between the laser chip 4021 and the lithium niobate chip 4024 in order to couple the divergent light emitted by the laser chip 4021 to the lithium niobate chip 4024.

[0076] The first lens 4022, located between the laser chip 4021 and the lithium niobate chip 4024, is used to couple the high-power light emitted by the laser chip 4021 to the lithium niobate chip 4024. Specifically, the first lens 4022 is a focusing lens, which couples the diverging light to the lithium niobate chip 4024.

[0077] The first lens 4022 can be a focusing lens, a collimating lens, and a focusing lens. When the first lens 4022 is both a collimating lens and a focusing lens, it includes a first sub-lens 40221 and a second sub-lens 40222. The first sub-lens 40221 is a collimating lens, and the second sub-lens 40222 is a focusing lens. The first sub-lens 40221 first collimates the diverging light to obtain collimated light. The second sub-lens 40222 then focuses and couples the collimated light into the lithium niobate chip 4024.

[0078] Since light coupled to the lithium niobate chip 4024 via the first lens 4022 may return along the original path, thereby damaging the laser chip 4021, an isolator 4023 is provided between the laser chip 4021 and the lithium niobate chip 4024 to prevent light coupled to the lithium niobate chip 4024 via the first lens 4022 from returning along the original path.

[0079] Isolator 4023 is used to prevent light coupled to the lithium niobate chip 4024 via the first lens 4022 from returning along the original path.

[0080] When the first lens 4022 is a focusing lens, the isolator 4023 is located between the first lens 4022 and the lithium niobate chip 4024; when the first lens 4022 is a collimating lens and a focusing lens, the isolator 4023 is located between the first sub-lens 40221 and the second sub-lens 40222.

[0081] The international standard for 50G GPON, ITU-T G.9804.3, was released in September 2021. To maintain the current PON link budget of 29dB / 32dB, the 50G PON standard requires the optical power transmitted by the OLT optical module to be ≥8.5dBm. The current conventional 53GBaud EML cannot meet the optical power requirements of 50G PON. To meet the 50G PON standard's requirements for the optical power transmitted by the OLT optical module, many major international manufacturers have developed EML+SOA chip solutions for 50G PON. However, these manufacturers are currently encountering insurmountable technical difficulties, and no EML+SOA optical device for 50GPON OLTs has yet been released. Therefore, no single optical module can meet the optical power requirements of 50G PON.

[0082] To address this issue, some embodiments propose that the optical module includes a combination of a DFB laser chip and a lithium niobate chip.

[0083] The 4024 lithium niobate chip comprises a substrate and a lithium niobate thin film. The substrate is a glass substrate, and the lithium niobate thin film is deposited on the substrate. The thickness of the lithium niobate thin film is less than 100 μm. Due to its smaller size and higher integration precision, the lithium niobate chip offers advantages over silicon photonics chips, such as lower power consumption and lower optical loss. Specifically, the optical loss of a silicon photonics chip is less than 11.2 dB, while the optical loss of a lithium niobate chip is less than 10 dB.

[0084] The thickness of the lithium niobate film is less than 100 μm. To further reduce the size of the lithium niobate chip, in some embodiments, the thickness of the lithium niobate film is less than 20 μm. To further reduce the size of the lithium niobate chip, the thickness of the lithium niobate film is less than 100 μm.

[0085] Because the optical loss of silicon photonics chips is less than 11.2 dB, the optical power emitted by the DFB laser chip must be greater than 158 mW to meet the optical power requirements of 50G PON in an optical module comprising a DFB laser chip and a silicon photonics chip. Similarly, because the optical loss of lithium niobate chips is less than 10 dB, the optical power emitted by the DFB laser chip must be greater than 80 mW to meet the optical power requirements of 50GPON in an optical module comprising a DFB laser chip and a lithium niobate chip.

[0086] Conventional DFB laser chips emit light with a power of less than 50mW, while high-power DFB laser chips emit light with a power of less than 120mW. Currently, it is difficult for DFB laser chips to achieve an optical power exceeding 120mW across the entire temperature range. Therefore, to ensure the optical module meets the power requirements of 50G PON, it must employ a combination of a DFB laser chip and a lithium niobate chip.

[0087] The lithium niobate chip 4024 is used for modulating high-power light. Specifically, the lithium niobate chip 4024 has an input interface and an output interface on one side. The chip contains an input optical waveguide, an MZM modulator, and an output optical waveguide. The input optical waveguide connects the input interface to the input terminal of the MZM modulator, and the output optical waveguide connects the output terminal of the MZM modulator to the output optical interface. High-power light enters the input optical waveguide of the lithium niobate chip 4024 through the input interface. Most of the high-power light received by the input optical waveguide enters the input terminal of the MZM modulator. The MZM modulator modulates the high-power light to obtain a modulated optical signal. The modulated optical signal is output from the output terminal of the MZM modulator to the output optical waveguide. Most of the modulated optical signal received by the output optical waveguide is output through the output interface. The modulated optical signal is a divergent optical signal.

[0088] The input and output interfaces of the lithium niobate chip 4024 can also be located on different sides of the lithium niobate chip 4024. However, if the input and output interfaces of the lithium niobate chip 4024 are located on different sides of the lithium niobate chip 4024, it may increase the length of the lithium niobate chip 4024, thereby increasing the length of the optical module encapsulated within it. Therefore, in order to reduce the length of the lithium niobate chip 4024, in some embodiments, the input and output interfaces can be located on one side of the lithium niobate chip 4024.

[0089] The surface of the lithium niobate chip 4024 is provided with a first power monitor and a second power monitor. The first power monitor is located near the input optical waveguide of the lithium niobate chip 4024, and the second power monitor is located near the output optical waveguide of the lithium niobate chip 4024. The first power monitor is used to monitor a small portion of the light received by the input optical waveguide to monitor the optical power, and the second power monitor is used to monitor a small portion of the optical signal received by the output optical waveguide to monitor whether the MZM modulator is at the optimal modulation point.

[0090] Lithium niobate chips can modulate high-power light (the light power emitted by laser chips is >80mW). The light loss of lithium niobate thin film modulators (light loss is less than 10dB) is less than that of silicon photonic chips (light loss is less than 11.2dB), so that the modulated light signal can meet the light power requirements of 50G PON.

[0091] The second lens 4025, located between the lithium niobate chip 4024 and the second filter 4026, is used to collimate the optical signal output from the lithium niobate chip 4024. Specifically, since the optical signal output from the lithium niobate chip 4024 is a divergent optical signal, the second lens 4025 is a collimating lens, which collimates the divergent optical signal output from the lithium niobate chip 4024 to obtain a collimated optical signal.

[0092] The second filter 4026 is used to transmit an optical signal of a specific wavelength and reflect the second optical signal to the third lens 4027. Specifically, the second filter 4026 is used to transmit an optical signal with a wavelength of λ1 and reflect the second optical signal to the third lens 4027. The optical signal emitted through the optical window of the transceiver housing is the first optical signal, and the optical signal entering through the optical window of the transceiver housing is the second optical signal.

[0093] The second filter 4026 can include either two 45° prisms, with their beveled edges bonded together, and one of the beveled edges coated with a filter film; or it can include a glass plate, with the end of the glass plate facing the optical fiber coated with a filter film. The design of the second filter 4026 including two 45° prisms facilitates manufacturing processes. The second filter 4026 includes a glass plate, which requires a filter holder to be fixed to the transceiver socket.

[0094] The third lens 4027, located between the second filter 4026 and the receiving deflection prism 40210, is used to couple the second optical signal reflected from the second filter 4026 to the receiving deflection prism 40210. Specifically, the third lens 4027 is a focusing lens, which focuses and couples the second optical signal reflected from the second filter 4026 to the receiving deflection prism 40210.

[0095] A receiving deflection prism 40210 is used to change the direction of the second optical signal so that the optical receiving chip 4028 can receive the second optical signal. Specifically, since the photosensitive surface of the optical receiving chip 4028 is set perpendicular to the third lens 4027, the optical receiving chip 4028 cannot receive the second optical signal without the receiving deflection prism 40210. The receiving deflection prism 40210 is located above the optical receiving chip 4028. The receiving deflection prism 40210 is used to change the direction of the second optical signal coupled to the third lens 4027 so that the optical receiving chip 4028 can receive the second optical signal.

[0096] In order to enable the optical receiver chip 4028 to receive as many second optical signals as possible, in some embodiments, the receiving deflection prism 40210 is disposed at the focal point of the optical receiver chip 4028.

[0097] The angle of the receiving deflection prism 40210 is 41° to 43°. Specifically, the angle of the receiving deflection prism 40210 cannot be set to 45° to avoid the second optical signal being incident perpendicularly on the light receiving chip and to reduce the reflection of the second optical signal. Therefore, the angle of the receiving deflection prism 40210 is generally set to 41° to 43°.

[0098] For example, the angle of the receiving prism 40210 is 42°, and the principal optical axis incident on the optical receiver chip 4028 is not perpendicular to the upper surface of the optical receiver chip 4028, but forms an angle of 84°. Thus, a small portion of the second optical signal incident on the optical receiver chip 4028, after being reflected by the optical receiver chip, cannot be reflected back to the fiber optic adapter 404 along the original optical path.

[0099] The receiving prism 40210 can be connected to the third lens 4027 or not. The receiving prism 40210 and the third lens 4027 are connected by refractive index matching adhesive.

[0100] When the receiving deflection prism 40210 is not connected to the third lens 4027, the second optical signal passes sequentially through the incident surface of the third lens 4027, the exit surface of the third lens 4027, the incident surface of the receiving deflection prism 40210, the reflecting surface of the receiving deflection prism 40210, and the exit surface of the receiving deflection prism 40210 to the optical receiving chip.

[0101] Light is reflected at the interface between two interfaces with different refractive indices. When the receiving prism 40210 and the third lens 4027 are not connected, the second light signal is easily reflected at the exit surface of the third lens 4027, and also easily reflected at the incident surface of the receiving prism 40210. However, when the receiving prism 40210 and the third lens 4027 are connected by refractive index matching adhesive, the adhesive makes it less likely for the exit surface of the third lens 4027 to reflect, and also less likely for the incident surface of the receiving prism 40210 to reflect, thus reducing the light loss of the second light signal.

[0102] The receiving prism 40210 is connected to the third lens 4027, which can not only reduce the optical loss of the second optical signal, but also reduce the space occupied by the optical module.

[0103] The optical receiver chip 4028, located vertically below the receiving deflection prism 40210, is used to convert the received second optical signal into a current signal. Specifically, the optical receiver chip 4028 has a photosensitive surface that receives the second optical signal, and the optical receiver chip 4028 converts the second optical signal into a current signal.

[0104] Due to the relatively large size of the lithium niobate chip, in order to package the lithium niobate chip into a conventionally sized optical module, the lithium niobate chip 4024 is located at the second end of the transceiver socket. The laser chip 4021, the first lens 4022, the isolator 4023, the second lens 4025, the second filter 4026, the third lens 4027, the receiving deflection prism 40210, and the optical receiver chip 4028 are all located at the first end of the transceiver socket 4012. The first end of the transceiver socket 4012 is the first end of the transceiver housing 401, and the second end of the transceiver socket 4012 is the second end of the transceiver housing 401.

[0105] The 40214 transimpedance amplifier chip is used to convert current signals into voltage signals.

[0106] Figure 17 This is a structural diagram of a third circuit board according to some embodiments. For example... Figure 4-17 As can be seen, in some embodiments, a cut-out area 3033 with an opening is provided at the first end of the third circuit board 303. The presence of the cut-out area 3033 makes the shape of the third circuit board 303 U-shaped. The cut-out area 3033 is used to place the lithium niobate chip 4024. In order to facilitate the placement of the lithium niobate chip 4024, the length of the cut-out area 3033 is greater than or equal to the length of the lithium niobate chip 4024, and the width of the cut-out area 3033 is greater than or equal to the width of the lithium niobate chip 4024.

[0107] The lithium niobate chip 4024 has a first wire bonding pin, and the third circuit board 303 has a second wire bonding pin, with the first and second wire bonding pins corresponding to each other. To minimize the wire bonding distance between the first wire bonding pin of the lithium niobate chip 4024 and the second wire bonding pin of the third circuit board 303, in some embodiments, the width of the cut-out area 3033 is equal to the width of the lithium niobate chip 4024, and the length of the cut-out area 3033 is equal to the length of the lithium niobate chip 4024.

[0108] like Figure 4-17 As can be seen, in some embodiments, the third circuit board 303 includes a first sub-circuit board 3031 and a second sub-circuit board 3032, which are integrally formed. The second sub-circuit board 3032 is located at the first end of the third circuit board 303, and the first sub-circuit board 3031 is located at the second end of the third circuit board 303. A second notch area 30322 is provided at the connection between the first sub-circuit board 3031 and the second sub-circuit board 3032, the second sub-circuit board 3032 is provided with a first notch area 30321, and the first sub-circuit board 3031 is provided with a cutout area 3033.

[0109] The first notch area 30321 is set to correspond to the optical receiver chip 4028, the connection area between the first side plate and the second side plate is set to correspond to the second notch area 30322, and the second notch area 30322 is closer to the gold fingers of the third circuit board 303 than the first notch area 30321.

[0110] The upper surface of the second sub-circuit board 3032 is lower than the upper surface of the first sub-circuit board 3031. That is, the second sub-circuit board 3032 is more recessed than the first sub-circuit board 3031.

[0111] In order to shorten the wire bonding length between the transimpedance amplifier chip 40214 and the optical receiver chip 4028 on the transceiver socket 4012, thereby improving the high-frequency performance of the signal line, in some embodiments, a second sub-circuit board 3032 is obtained by removing several layers from a portion of the first sub-circuit board 3031, so that the second sub-circuit board 3032 is more recessed relative to the first sub-circuit board 3031, and the transimpedance amplifier chip 40214 and some resistors and capacitors are disposed on the second sub-circuit board 3032.

[0112] The first end of the first sub-circuit board 3031 is close to the laser chip 4021. A gold finger is provided at the second end of the first sub-circuit board 3031. The third end of the first sub-circuit board 3031 is close to the optical receiver chip 4028. The third end of the first sub-circuit board 3031 is connected to the second sub-circuit board 3032, but the third end of the first sub-circuit board 3031 is not connected to the first end of the first sub-circuit board 3031. Both the first and third ends of the first sub-circuit board 3031 are located at the first end of the transceiver socket 4012, and the second end of the first sub-circuit board 3031 is located at the second end of the transceiver socket 4012.

[0113] Figure 18 This is a structural diagram of an optical fiber adapter, focusing ring, fourth lens, and lens mount according to some embodiments. Figure 19 This is an exploded view of a fiber optic adapter, adjustment ring, fourth lens, and lens mount according to some embodiments. Figure 4-19 As can be seen, in some embodiments, a storage cavity is provided within the lens holder 405, and a fourth lens 4029 is placed within this cavity. The fourth lens 4029 is bonded to the storage cavity with adhesive. The fourth lens 4029 is a focusing lens. The focusing lens is used to couple the first optical signal transmitted through the second filter 4026 to the optical fiber ferrule in the optical fiber adapter 404, and also to collimate the second optical signal incident from the optical fiber ferrule in the optical fiber adapter 404 into the second filter 4026.

[0114] like Figure 4-19 As can be seen, in some embodiments, a focusing cavity is provided inside the focusing ring 406, and the focusing cavity is engaged with the end of the fiber optic adapter 404 facing the transceiver housing 401. During installation, the fiber optic adapter 404 and the lens mounting base 405 are fixed in relative position by optical coupling, and then the focusing ring 406 is used to fix the relative position of the fiber optic adapter 404 and the lens mounting base 405.

[0115] Figure 20 This is a first structural diagram of a transceiver socket according to some embodiments. Figure 21 This is a second structural diagram of a transceiver socket according to some embodiments. Figure 22 This is a third structural diagram of a transceiver socket according to some embodiments. Figure 23 This is an exploded view of a transceiver socket according to some embodiments. Figure 24 This is a first cross-sectional view of a transceiver socket according to some embodiments. Figure 25 This is a second cross-sectional view of a transceiver socket according to some embodiments. For example... Figure 4-25 It is understood that in some embodiments, the first end of the transceiver socket 4012 is provided with a light-transmitting hole 401211 and a light window 401212, and the second end of the transceiver socket 4012 is provided with an insertion port 401213.

[0116] The light-transmitting aperture 401211 extends from the inner surface of the first end of the transceiver socket 4012 to the outer surface of the first end of the transceiver socket 4012. The light-transmitting aperture 401211 is used to transmit the first optical signal emitted by the laser chip 4021 out of the transceiver housing 401, and also to transmit the second optical signal emitted by the fiber optic adapter 404 into the transceiver housing 401.

[0117] In order to project the first optical signal emitted by the laser chip 4021 as far as possible outside the transceiver housing 401 and to project the second optical signal emitted by the fiber optic adapter 404 as far as possible into the transceiver housing 401, the light-transmitting aperture 401211, the second lens 4025, and the second filter 4026 are aligned in a straight line.

[0118] The light window 401212 and the light aperture 401211 are correspondingly arranged, and a flat window glass 407 is provided at the light window 401212. The flat window glass 407 is sealed and welded to the light window 401212. The flat window glass 407 not only facilitates the emission of the first light signal and the injection of the second light signal, but also seals the transceiver housing 401.

[0119] The third circuit board 303 is inserted into the transceiver housing 401 via the insertion port 401213. To make the transceiver housing 401 a sealed housing, in addition to the sealed connection between the upper cover 4011 and the transceiver socket 4012, and the provision of a flat window glass 407 at the first end of the transceiver socket 4012, the third circuit board 303 is also soldered to the insertion port 401213. Copper foil is laid on the area of ​​the third circuit board 303 corresponding to the insertion port 401213. The transceiver socket 4012 is a metal transceiver socket, and the area of ​​the third circuit board 303 corresponding to the insertion port 401213 is soldered to the insertion port 401213 of the transceiver socket 4012.

[0120] like Figure 4-24 It is understood that in some embodiments, the transceiver socket 4012 includes a transceiver base plate and a transceiver side plate, and the transceiver side plate and the transceiver base plate form a cavity without a top cover.

[0121] The first end of the transceiver side plate is provided with a light-transmitting hole 401211 and a light window 401212, and the second end of the transceiver side plate is provided with an insertion port 401213.

[0122] The receiving / dispatching base plate includes a tube holder body 40121, a storage slot 40122, and a first support protrusion 40123. The degree of concavity of the storage slot 40122, the tube holder body 40121, and the first support protrusion 40123 decreases sequentially. That is, the storage slot 40122 is more concave than the tube holder body 40121, and the tube holder body 40121 is more concave than the first support protrusion 40123.

[0123] The tube base body 40121 is the area in the receiving and dispatching base plate located between the first support protrusion 40123 and the receiving and dispatching side plate, excluding the storage slot 40122.

[0124] The tube socket body 40121 has a light receiving chip 4028 disposed on it. Specifically, a heat sink substrate is disposed on the tube socket body 40121, and the light receiving chip 4028 is disposed on the heat sink substrate. The light receiving chip 4028 is disposed corresponding to the first notch area 30321 of the third circuit board 303. Since the optical path of the second optical signal needs to be deflected by a receiving deflection prism, the upper surface of the light receiving chip 4028 must be much lower than the upper surface of the lithium niobate chip 4024. However, the upper surface of the third circuit board 303 is at approximately the same height as the upper surface of the lithium niobate chip 4024. Therefore, the light receiving chip 4028 cannot be directly placed on the third circuit board 303, but is placed on the tube socket body 40121 through the heat sink substrate. That is, the light receiving chip 4028 is bonded to the heat sink substrate, and the heat sink substrate is bonded to the tube socket body 40121.

[0125] The storage slot 40122, located at the first end of the transceiver base plate, between the light-transmitting hole 401211 and the first support protrusion 40123, is used to house a semiconductor cooler (TEC). The TEC and the light-receiving chip 4028 are located on opposite sides of the first support protrusion 40123. The TEC is used to control the temperature of the laser chip 4021 so that the laser chip 4021 emits light of a specific wavelength.

[0126] If the TEC is placed directly on the socket body 40121, to ensure that the optical waveguide of the laser chip 4021 above the TEC is on the same horizontal plane as the optical waveguide of the lithium niobate chip 4024, the position height of the first support protrusion 40123 needs to be increased. This, in turn, requires increasing the position height of the insertion port 401213, the light-transmitting hole 401211, and the optical receiver chip 4028. Increasing the position height of the optical receiver chip 4028 necessitates increasing the position height of the heat sink substrate below it. Therefore, placing the TEC on the socket body 40121 is not recommended. Increasing the position height of the insertion port 401213 may prevent the third circuit board 303 from being inserted into the socket body 40121 via the insertion port 401213. Therefore, the TEC cannot be placed directly on the socket body 40121. Increasing the position height of the light-transmitting hole 401211 also requires adjusting the position height of the fiber optic adapter 404. Since the position and height of the fiber optic adapter 404 are fixed, the position of the light-transmitting hole 401211 is also fixed. Therefore, the TEC cannot be placed directly on the tube socket body 40121. In order to make the optical waveguide of the laser chip 4021 above the TEC and the optical waveguide of the lithium niobate chip 4024 on the same horizontal plane, and without increasing the position and height of the first support protrusion 40123, in some embodiments, the TEC is placed in the storage slot 40122, and the storage slot 40122 is more recessed relative to the tube socket body 40121.

[0127] Because the thickness tolerance of the TEC is poorly controlled, the height difference between the light output port of the laser chip 4021 and the input interface of the lithium niobate chip 4024 is significant. Consequently, the first lens 4022 can only couple a small portion of the light of a specific wavelength emitted by the laser chip 4021 into the lithium niobate chip 4024, resulting in low coupling efficiency. To avoid this problem, in some embodiments, a first ceramic substrate is bonded to the TEC.

[0128] A second ceramic substrate is disposed on the first ceramic substrate, and a laser chip 4021 and a thermistor are disposed on the second ceramic substrate.

[0129] The presence of the first ceramic substrate can reduce the height difference between the light output port of the laser chip 4021 and the input interface of the lithium niobate chip 4024, so that the light output port of the laser chip 4021 and the input interface of the lithium niobate chip 4024 are located on the same horizontal plane as much as possible, thereby improving the coupling efficiency.

[0130] In addition to the second ceramic substrate, the first lens 4022, and the second filter 4026, the first ceramic substrate also includes a switching circuit. The switching circuit connects the TEC, the laser chip 4021, and the thermistor to the third circuit board 303.

[0131] A laser chip 4021 and a thermistor are disposed on the second ceramic substrate.

[0132] The thermistor, located near the laser chip 4021, is used to monitor the temperature changes of the laser chip 4021.

[0133] In addition to the laser chip 4021 and the thermistor, the second ceramic substrate also contains a circuit. This circuit is used to connect the laser chip 4021 and the thermistor to the adapter circuit.

[0134] The first support protrusion 40123 is located on the tube base body 40121. The first end of the first support protrusion 40123 is connected to the first end of the transceiver side plate, while the second end and side of the first support protrusion 40123 are not connected to the transceiver side plate.

[0135] A second support protrusion 40124 is provided on the first support protrusion 40123. The first end of the first support protrusion 40123 is connected to the first end of the tube base body 40121, and the second end of the first support protrusion 40123 is connected to the second support protrusion 40124. The second support protrusion 40124 is located at the second end of the tube base body 40121. An isolator 4023, a second lens 4025, a third lens 4027, and a receiving deflection prism 40210 are provided on the first support protrusion 40123, and a lithium niobate chip 4024 is provided on the second support protrusion 40124.

[0136] The height of the first support protrusion 40123 is less than or equal to the height of the second support protrusion 40124. Specifically, the thickness of the lithium niobate chip 4024 is approximately 500 μm, and the height of the second lens 4025 is 1 mm, meaning the height difference between the center of the second lens 4025 and its lower surface is 500 μm. During the assembly of the optical module, the position of the second lens 4025 needs to be moved up, down, left, and right to ensure that the second lens 4025 collimates as much as possible the modulated optical signal modulated by the lithium niobate chip 4024. Therefore, the height of the first support protrusion 40123 where the second lens 4025 is located is lower than the height of the second support protrusion 40124 where the lithium niobate chip 4024 is located.

[0137] However, if the thickness of the lithium niobate chip 4024 is about 550μm, since the height difference between the center of the second lens 4025 and the lower surface of the second lens 4025 is 500μm, the height of the first support protrusion 40123 where the second lens 4025 is located is equal to the height of the second support protrusion 40124 where the lithium niobate chip 4024 is located.

[0138] The first support protrusion 40123 includes a first side plate and a second side plate. The first end of the first side plate is connected to the first end of the receiving / distributing side plate, and the second end of the first side plate is connected to the first end of the second side plate. The first side plate is connected to the first side wall of the storage slot 40122, and the second side plate is connected to the second side wall of the storage slot 40122. The connection area between the first and second side plates corresponds to the second notch area 30322 of the third circuit board 303, and the first side wall of the storage slot 40122 is connected to the second side wall of the storage slot 40122.

[0139] The first side plate is provided with a third lens 4027 and a receiving prism 40210, the first end of the second side plate is provided with an isolator 4023 and a second lens 4025, and the second end of the second side plate is provided with a second support protrusion 40124.

[0140] The first support protrusion 40123 is L-shaped. Specifically, the first side plate and the second side plate of the first support protrusion 40123 form an L-shaped support protrusion.

[0141] Figure 26 This is a first optical path diagram of an optical module according to some embodiments. For example... Figure 4-26 As can be seen, in some embodiments, the laser chip 4021 emits light of a specific wavelength, and the first lens 4022 couples the light of the specific wavelength emitted by the laser chip to the lithium niobate chip 4024. The light of the specific wavelength is modulated by the lithium niobate chip 4024 to obtain a modulated optical signal. The modulated optical signal is collimated by the second lens 4025 to obtain a collimated optical signal. The collimated optical signal passes through the second filter 4026 and is then coupled to the optical fiber ferrule of the optical fiber adapter 404 by the fourth lens 4029. Here, the light with wavelength λ1 is the light of the specific wavelength.

[0142] like Figure 4-26 As can be seen, in some embodiments, the fiber optic ferrule of the fiber optic adapter 404 emits a second optical signal. The second optical signal is collimated by the fourth lens 4029 to obtain a collimated optical signal. The collimated optical signal is reflected by the second filter 4026 to the third lens 4027. The third lens 4027 couples the second optical signal reflected by the second filter 4026 to the receiving deflection prism 40210. The second optical signal is changed in direction by the receiving deflection prism 40210 and then incident into the optical receiver chip 4028.

[0143] This application provides an optical module, including an optical transceiver assembly. The optical transceiver assembly includes a transceiver housing and a third circuit board. The transceiver housing has a first end with an optical window for optical signals to exit or enter, and a second end with an insertion port for the third circuit board. Optical components are housed inside. The third circuit board has a cut-out area. A first optical signal in the transceiver housing exits through the optical window, and a second optical signal from the fiber optic adapter enters the transceiver housing through the optical window. The circuit board extends into the transceiver housing through the insertion port. To ensure a tight seal between the circuit board and the transceiver housing, copper foil is laid on the area of ​​the circuit board corresponding to the insertion port. The transceiver housing is a metal transceiver housing, and the circuit board is soldered to the insertion port of the transceiver housing to ensure a tight seal between the circuit board and the transceiver housing. The optical components include a laser chip, a first lens, a lithium niobate chip, a second lens, a second filter, a third lens, a receiving prism, and a light receiving chip. The laser chip, first lens, second lens, second filter, third lens, receiving prism, and light receiving chip are all located at the first end of the transceiver housing, and the lithium niobate chip is located at the second end of the transceiver housing. The laser chip is a high-power DFB laser chip. The high-power DFB laser chip is used to emit high-power light. A first lens, located between the laser chip and the lithium niobate chip, is used to couple the high-power light to the lithium niobate chip. The lithium niobate chip, corresponding to the cut-out area, includes a substrate and a lithium niobate thin film, with an optical loss of less than 10dB, and is used to modulate the high-power light to obtain a modulated optical signal. The lithium niobate thin film is deposited on the substrate and has a thickness of less than 100μm. Due to the smaller size and higher integration precision of the lithium niobate chip, it has advantages such as lower power consumption and lower optical loss compared to silicon photonics chips. Specifically, the optical loss of the silicon photonics chip is less than 11.2dB, and the optical loss of the lithium niobate chip is less than 10dB. Because the optical loss of the silicon photonics chip is less than 11.2dB, in order for the optical module including the DFB laser chip + silicon photonics chip combination to meet the optical power requirements of 50G PON, the optical power emitted by the DFB laser chip must be >158mW. Because the optical loss of lithium niobate chips is less than 10dB, to ensure that the optical module combining a DFB laser chip and a lithium niobate chip meets the optical power requirements for 50G PON, the optical power emitted by the DFB laser chip must be greater than 80mW. Conventional DFB laser chips emit optical power less than 50mW, and high-power DFB laser chips emit optical power less than 120mW. Currently, it is difficult for DFB laser chips to achieve an optical power exceeding 120mW across the entire temperature range. Therefore, to meet the optical power requirements for 50G PON, the optical module must use a combination of a DFB laser chip and a lithium niobate chip. A second lens, located between the lithium niobate chip and the second filter, is used to collimate the modulated optical signal to obtain a collimated optical signal. A second filter, located between the laser chip and the third lens, is used to transmit the collimated optical signal to the fiber optic adapter.A third lens, located between the second filter and the receiving deflection prism, couples the second optical signal reflected from the second filter to the receiving deflection prism. The receiving deflection prism, located above the optical receiving chip, modulates the second optical signal so that it is reflected back to the optical receiving chip. In this application, the laser chip provides high-power light, and the optical loss of the lithium niobate chip is less than that of the silicon photonics chip, ensuring that the modulated optical signal modulated by the lithium niobate chip meets the optical power requirements for 50G PON transmission.

[0144] Since (1) the first lens 402 can be not only a single focusing lens, but also includes a first sub-lens 40221 and a second sub-lens 40222, the first sub-lens 40221 is located between the laser chip 4021 and the isolator 4023, and the second sub-lens 40222 is located between the isolator 4023 and the lithium niobate chip 4024, the first sub-lens 40221 is a collimating lens, and the second sub-lens 40222 is a focusing lens; (2) the second filter 4026 can include two 45° prisms, with the bevels of the two 45° prisms bonded together, and one of the bevels coated with a filter film; or it can include a glass plate, wherein the end of the glass plate facing the optical fiber is coated with a filter film, and the glass plate is fixed to the transceiver socket by a filter support; (3) the receiving turning prism 40210 can be connected to the third lens 4027 or not connected to the third lens 4027. In some embodiments, not only is provided Figure 26 The first optical path diagram shown can also provide a second type of optical path diagram.

[0145] Figure 27 This is a second optical path diagram of an optical module according to some embodiments. For example... Figure 27 As can be seen, in some embodiments, the laser chip 4021 emits light of a specific wavelength, the first sub-lens 40221 collimates the light of the specific wavelength emitted by the laser chip to obtain collimated light, the second sub-lens 40222 couples the collimated light to the lithium niobate chip 4024, the light of the specific wavelength is modulated by the lithium niobate chip 4024 to obtain a modulated optical signal, the modulated optical signal is collimated by the second lens 4025 to obtain a collimated optical signal, the collimated optical signal passes through the second filter 4026 and is coupled to the optical fiber ferrule of the optical fiber adapter 404 by the fourth lens 4029.

[0146] like Figure 27As can be seen, in some embodiments, the fiber optic ferrule of the fiber optic adapter 404 emits a second optical signal. The second optical signal is collimated by the fourth lens 4029 to obtain a collimated optical signal. The collimated optical signal is reflected by the second filter 4026 to the third lens 4027. The third lens 4027 couples the second optical signal reflected by the second filter 4026 to the receiving deflection prism 40210. The second optical signal is changed in direction by the receiving deflection prism 40210 and then incident into the optical receiver chip 4028.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An optical module whose transmitted optical power meets the 50G PON standard, characterized in that, include: Optical transceiver assembly, including transceiver housing and third circuit board; The transceiver housing has a light window at the first end for emitting or receiving light signals, an insertion port at the second end for inserting a third circuit board, and an optical component inside. The third circuit board has a cut-out area; Optical components include a laser chip, a first lens, a lithium niobate chip, a second lens, a second filter, a third lens, a receiving prism, and a light receiving chip. The laser chip, first lens, second lens, second filter, receiving prism, third lens and optical receiving chip are all located at the first end of the transceiver housing, and the lithium niobate chip is located at the second end of the transceiver housing; The first lens is located between the laser chip and the lithium niobate chip; The lithium niobate chip, corresponding to the hollowed-out area, includes a substrate and a lithium niobate thin film, with an optical loss of less than 10dB; A lithium niobate thin film, deposited on a substrate, with a thickness of less than 100 μm; The second lens is located between the lithium niobate chip and the second filter; The second filter is located between the laser chip and the third lens; The receiving deflection prism is located above the optical receiving chip.

2. The optical module according to claim 1, characterized in that, The transceiver housing includes a transceiver tube socket, and the transceiver tube socket includes a transceiver side plate and a transceiver bottom plate; The transceiver side plate and the transceiver base plate form a coverless cavity, with the light window and light passage hole provided at the first end and the insertion port provided at the second end; The light-transmitting hole extends from the inner surface of the first end of the transceiver side plate to the outer surface of the first end of the transceiver side plate. The receiving and sending base plate is provided with a tube seat body, a storage slot and a first support protrusion; The first support protrusion has its first end connected to the first end of the transceiver side plate, while its side and second end are not connected to the transceiver side plate. The degree of concavity of the first support protrusion, the tube base body, and the storage groove increases sequentially; The optical receiving chip is disposed on the tube socket body.

3. The optical module according to claim 2, characterized in that, The first support protrusion includes a first side plate and a second side plate; The first side plate has a first end connected to the first end of the transceiver side plate and a second end connected to the second side plate, and is provided with the third lens. The second side plate is provided with a second support protrusion and a second lens; The second support protrusion is provided corresponding to the hollowed-out area, and the lithium niobate chip is provided on it.

4. The optical module according to claim 3, characterized in that, The height of the first support protrusion is less than or equal to the height of the second support protrusion.

5. The optical module according to claim 3, characterized in that, It also includes circuit boards; The circuit board includes a first circuit board, a second circuit board, and the third circuit board; The first circuit board has a first end connected to the second end of the second circuit board, and the second end is provided with gold fingers; The second circuit board has its first end connected to the second end of the third circuit board; The third circuit board, with its first end extending into the transceiver socket through the insertion port, includes a first sub-circuit board and a second sub-circuit board. The first sub-circuit board has a second notch area at the connection point with the second sub-circuit board, and the hollowed-out area is provided; The second sub-circuit board has a first notch area, which is more recessed than the first sub-circuit board; The first notch region is configured to correspond to the optical receiving chip; The second notch area is provided corresponding to the connection area of ​​the first side plate and the second side plate, and is closer to the gold fingers of the third circuit board than the first notch area; The hollowed-out area is provided with an opening, which is provided corresponding to the second support protrusion.

6. The optical module according to claim 1, characterized in that, The second filter may include two 45° prisms, with the beveled edges of the two 45° prisms bonded together, and one of the beveled edges coated with a filter film; or it may include only a glass plate, wherein the side of the glass plate facing the optical fiber is coated with a filter film.

7. The optical module according to claim 1, characterized in that, The first lens can be a focusing lens; or it can be a collimating lens and a focusing lens.

8. The optical module according to claim 1, characterized in that, The receiving deflection prism may or may not be connected to the third lens, wherein the angle of the receiving deflection prism is 41° to 43°.

9. The optical module according to claim 1, characterized in that, The optical transceiver assembly also includes a lens mount and an optical fiber adapter; The lens holder has a fourth lens inside, which is connected to the first end of the transceiver housing; The fiber optic adapter is connected to the lens mount; The fourth lens is used to couple the optical signal transmitted through the second filter to the optical fiber adapter, and also to collimate the second optical signal incident on the optical fiber adapter and then project it into the second filter.

10. The optical module according to claim 1, characterized in that, The storage compartment shown is equipped with a TEC; The TEC is provided with a first ceramic substrate; The first ceramic substrate is provided with a second ceramic substrate, a first lens and a second filter; The second ceramic substrate is provided with the laser chip and the thermistor; The thermistor is used to monitor the temperature change of the laser chip.

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