CN117677878A

CN117677878A - Optical module

Info

Publication number: CN117677878A
Application number: CN202280050029.3A
Authority: CN
Inventors: 吴涛; 金爽; 濮宏图; 慕建伟
Original assignee: Hisense Broadband Multimedia Technology Co Ltd
Current assignee: Hisense Broadband Multimedia Technology Co Ltd
Priority date: 2021-08-31
Filing date: 2022-06-28
Publication date: 2024-03-08

Abstract

A light module (200) includes a housing, a circuit board (300), and a light emitting device (400). The housing comprises an upper housing (201) and a lower housing (202); the circuit board (300) comprises a front surface and a back surface and comprises a mounting hole (320), and the mounting hole (320) penetrates through the front surface and the back surface; the light emitting device (400) is mounted on a circuit board (300) and includes a base (410), a laser (420), a translating prism (440), and a fiber coupler (4710,4720,470). The base (410) is mounted on the front surface and is provided with a mounting surface and a bottom surface which are opposite to each other, the mounting surface faces the front surface, and the bottom surface faces the upper shell (201); the laser (420) is arranged on the mounting surface, penetrates through the mounting hole (320) and extends out of the back surface of the circuit board (300); a translation prism (440) is mounted on the mounting surface and configured to translate a laser beam emitted by the laser (420) on a back side of the circuit board (300) to a front side of the circuit board (300); the fiber coupler (4710,4720) is configured to transmit a laser beam, which translates the translating prism (440) to the front side of the circuit board (300), to the outside of the optical module (200).

Description

Optical module

The present application claims the priority of the chinese patent application of application number 202111012383.0, 2021, 8, 31, 202111015876.X, 2021, 8, 31, 202111015574.2, 202111015786.0, 202111015461.2, 2021, 8, 31, 202122087755.8, 202122085678.2, 2021, 31, 202122085677.8, 202122087754.3, and 202122076596.1, the contents of which are incorporated herein by reference.

Technical Field

The disclosure relates to the technical field of optical fiber communication, and in particular relates to an optical module.

Background

With the development of new business and application modes such as cloud computing, mobile internet, video conference, etc., the development and progress of optical communication technology are becoming more important. In the optical communication technology, the optical module is a tool for realizing the mutual conversion of photoelectric signals, and is one of key devices in optical communication equipment.

Disclosure of Invention

Some embodiments of the present disclosure provide an optical module. The light module includes a housing, a circuit board, and a light emitting device. The shell comprises an upper shell and a lower shell; the circuit board is positioned between the upper shell and the lower shell, the circuit board is provided with a front surface facing the upper shell and a back surface facing the lower shell, and comprises a mounting hole which penetrates through the front surface and the back surface; the light emitting device is mounted on the circuit board and comprises a base, a laser, a translation prism and an optical fiber coupler. The base is mounted on the front surface of the circuit board and is provided with a mounting surface and a bottom surface opposite to the mounting surface, the mounting surface faces the front surface, and the bottom surface faces the upper shell; the laser is arranged on the mounting surface, penetrates through the mounting hole and extends out of the back surface of the circuit board; the translation prism is arranged on the mounting surface, one part of the translation prism is positioned on the back side of the circuit board through the mounting hole, the other part of the translation prism is positioned on the front side of the circuit board, and the translation prism is configured to translate a laser beam emitted by the laser and positioned on the back side of the circuit board to the front side of the circuit board; the fiber coupler is configured to transmit the laser beam translated by the translating prism to the front side of the circuit board to the outside of the optical module.

Drawings

In order to more clearly illustrate the technical solutions of the present disclosure, the drawings that need to be used in some embodiments of the present disclosure will be briefly described below, and it is apparent that the drawings in the following description are only drawings of some embodiments of the present disclosure, and other drawings may be obtained according to these drawings to those of ordinary skill in the art. Furthermore, the drawings in the following description may be regarded as schematic diagrams, not limiting the actual size of the products, the actual flow of the methods, the actual timing of the signals, etc. according to the embodiments of the present disclosure.

Fig. 1 is a connection diagram of an optical communication system according to some embodiments;

fig. 2 is a block diagram of an optical network terminal according to some embodiments;

FIG. 3 is a block diagram of an optical module according to some embodiments;

fig. 4 is an exploded structural view of an optical module according to some embodiments;

FIG. 5 is a block diagram of an optical module with a housing and unlocking component removed, according to some embodiments;

FIG. 6 is a block diagram of a light emitting device in a light module according to some embodiments;

FIG. 7 is a partial light path diagram of a light emitting device in a light module according to some embodiments;

Fig. 8 is a block diagram of a circuit board in an optical module according to some embodiments;

fig. 9A is an assembled block diagram of a circuit board and light emitting devices in an optical module according to some embodiments;

FIG. 9B is an assembled block diagram of a circuit board and light emitting devices at another angle in an optical module according to some embodiments;

FIG. 10A is a side view of a circuit board and light emitting device assembly in an optical module according to some embodiments;

FIG. 10B is a cross-sectional view of a circuit board and light emitting device assembly in an optical module according to some embodiments;

FIG. 11A is an electrical connection diagram of a circuit board and a light emitting device in an optical module according to some embodiments;

FIG. 11B is another electrical connection diagram of a circuit board and a light emitting device in an optical module according to some embodiments;

fig. 12A is a block diagram of a base in an optical module, according to some embodiments;

FIG. 12B is a block diagram of another angle of a base in an optical module, according to some embodiments;

FIG. 13 is a diagram of a heat dissipation channel of an optical module, according to some embodiments;

FIG. 14A is a cross-sectional view of a monitoring optical path of a light detector in an optical module according to some embodiments;

FIG. 14B is a top view of a monitoring optical path of a photodetector in an optical module according to some embodiments;

Fig. 15A is an assembled structure diagram of a circuit board and a light receiving device in an optical module according to some embodiments;

fig. 15B is a block diagram of a light receiving device in an optical module according to some embodiments;

fig. 15C is a partial light path diagram of a light receiving device in a light module according to some embodiments;

fig. 16A is a structural view of a light emitting device in an optical module according to some modifications;

FIG. 16B is a block diagram of a base of the light emitting device of FIG. 16A;

fig. 17A is a structural diagram of a light emitting device in an optical module according to some modifications;

FIG. 17B is a block diagram of a base of the light emitting device of FIG. 17A;

fig. 18A is an assembly structural view of a circuit board, a light emitting device, and a light receiving device in an optical module according to still another modification;

FIG. 18B is a block diagram of the light module shown in FIG. 18A with the light emitting devices omitted;

fig. 18C is a cross-sectional view of an assembled structure of a circuit board and a light receiving device in an optical module according to some embodiments;

fig. 19A is a structural view of a light emitting device in an optical module according to still other modifications;

FIG. 19B is a block diagram of a chassis of the optical module shown in FIG. 19A;

fig. 20A is a structural view of a light emitting device in an optical module according to still other modifications;

Fig. 20B is a block diagram of a chassis in the optical module shown in fig. 20A.

Detailed Description

The following description of the embodiments of the present disclosure will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present disclosure. All other embodiments obtained by one of ordinary skill in the art based on the embodiments provided by the present disclosure are within the scope of the present disclosure.

Throughout the specification and claims, unless the context requires otherwise, the word "comprise" and its other forms such as the third person referring to the singular form "comprise" and the present word "comprising" are to be construed as open, inclusive meaning, i.e. as "comprising, but not limited to. In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", "some examples", "and the like are intended to indicate that a particular feature, structure, material, or characteristic associated with the embodiment or example is included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The terms "first" and "second" are used below for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the embodiments of the present disclosure, unless otherwise indicated, the meaning of "a plurality" is two or more.

In describing some embodiments, expressions of "coupled" and "connected" and their derivatives may be used. For example, the term "connected" may be used in describing some embodiments to indicate that two or more elements are in direct physical or electrical contact with each other. As another example, the term "coupled" may be used in describing some embodiments to indicate that two or more elements are in direct physical or electrical contact. However, the term "coupled" or "communicatively coupled (communicatively coupled)" may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments disclosed herein are not necessarily limited to the disclosure herein.

At least one of "A, B and C" has the same meaning as at least one of "A, B or C," both include the following combinations of A, B and C: a alone, B alone, C alone, a combination of a and B, a combination of a and C, a combination of B and C, and a combination of A, B and C.

"A and/or B" includes the following three combinations: only a, only B, and combinations of a and B.

The use of "adapted" or "configured to" herein is meant to be an open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

As used herein, "about," "approximately" or "approximately" includes the stated values as well as average values within an acceptable deviation range of the particular values as determined by one of ordinary skill in the art in view of the measurement in question and the errors associated with the measurement of the particular quantity (i.e., limitations of the measurement system).

As used herein, "parallel", "perpendicular", "equal" includes the stated case as well as the case that approximates the stated case, the range of which is within an acceptable deviation range as determined by one of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., limitations of the measurement system). For example, "parallel" includes absolute parallel and approximately parallel, where the acceptable deviation range for approximately parallel may be, for example, a deviation within 5 °; "vertical" includes absolute vertical and near vertical, where the acceptable deviation range for near vertical may also be deviations within 5 °, for example. "equal" includes absolute equal and approximately equal, where the difference between the two, which may be equal, for example, is less than or equal to 5% of either of them within an acceptable deviation of approximately equal.

In the optical communication technology, light is used to carry information to be transmitted, and an optical signal carrying the information is transmitted to an information processing device such as a computer through an information transmission device such as an optical fiber or an optical waveguide, so as to complete the transmission of the information. Since the optical signal has a passive transmission characteristic when transmitted through an optical fiber or an optical waveguide, low-cost and low-loss information transmission can be realized. Further, since a signal transmitted by an information transmission device such as an optical fiber or an optical waveguide is an optical signal and a signal that can be recognized and processed by an information processing device such as a computer is an electrical signal, it is necessary to perform mutual conversion between the electrical signal and the optical signal in order to establish an information connection between the information transmission device such as an optical fiber or an optical waveguide and the information processing device such as a computer.

The optical module realizes the function of interconversion between the optical signal and the electric signal in the technical field of optical fiber communication. The optical module comprises an optical port and an electric port, the optical module realizes optical communication with information transmission equipment such as optical fibers or optical waveguides through the optical port, realizes electric connection with an optical network terminal (for example, optical cat) through the electric port, and is mainly used for realizing power supply, two-wire synchronous serial (Inter-Integrated Circuit, I2C) signal transmission, data signal transmission, grounding and the like; the optical network terminal transmits the electric signal to information processing equipment such as a computer through a network cable or wireless fidelity (Wi-Fi).

Fig. 1 is a connection diagram of an optical communication system according to some embodiments. As shown in fig. 1, 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.

One end of the optical fiber 101 is connected to the remote server 1000, and the other end is connected to the optical network terminal 100 through the optical module 200. The optical fiber itself can support long-distance signal transmission, such as signal transmission of several kilometers (6-8 kilometers), on the basis of which, if a repeater is used, it is theoretically possible to realize ultra-long-distance transmission. Thus, in a typical optical communication system, the distance between the remote server 1000 and the optical network terminal 100 may typically reach several kilometers, tens of kilometers, or hundreds of kilometers.

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 apparatus 2000 may be any one or several of the following: routers, switches, computers, cell phones, tablet computers, televisions, etc.

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 apparatus 2000 and the optical network terminal 100. The connection between the local information processing device 2000 and the remote server 1000 is completed by an optical fiber 101 and a network cable 103; and the connection between the optical fiber 101 and the network cable 103 is made by the optical module 200 and the optical network terminal 100.

The optical network terminal 100 includes a substantially rectangular parallelepiped housing (housing), and an optical module interface 102 and a network cable interface 104 provided on the housing. The optical module interface 102 is configured to access the optical module 200, so that the optical network terminal 100 and the optical module 200 establish a bidirectional electrical signal connection; the network cable interface 104 is configured to access the network cable 103 such that the optical network terminal 100 establishes a bi-directional electrical signal connection with the network cable 103. A connection is established between the optical module 200 and the network cable 103 through the optical network terminal 100. Illustratively, the optical network terminal 100 transmits an electrical signal from the optical module 200 to the network cable 103, and transmits an electrical signal from the network cable 103 to the optical module 200, so that the optical network terminal 100, as a host computer of the optical module 200, can monitor the operation of the optical module 200. The upper computer of the optical module 200 may include an optical line terminal (Optical Line Terminal, OLT) or the like in addition to the optical network terminal 100.

The optical module 200 includes an optical port and an electrical port. The optical port is configured to connect with the optical fiber 101 such that the optical module 200 establishes a bi-directional optical signal connection with the optical fiber 101; the electrical port is configured to be accessed into the optical network terminal 100 such that the optical module 200 establishes a bi-directional electrical signal connection with the optical network terminal 100. The optical module 200 performs mutual conversion between optical signals and electrical signals, so that a connection is established between the optical fiber 101 and the optical network terminal 100. Illustratively, 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 input to the optical fiber 101. Since the optical module 200 is a tool for implementing photoelectric signal conversion, it has no function of processing data, and information is not changed during the photoelectric conversion.

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

Fig. 2 is a block diagram of an optical network terminal according to some embodiments. In order to clearly show the connection relationship of the optical module 200 and the optical network terminal 100, fig. 2 shows only the structure of the optical network terminal 100 related to the optical module 200. As shown in fig. 2, the optical network terminal 100 further includes a circuit board 105 disposed in the housing, a cage 106 disposed on a 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 access an electrical port of the optical module 200; the heat sink 107 has a convex structure such as a fin for increasing a heat dissipation area.

The optical module 200 is inserted into the cage 106 of the optical network terminal 100, the optical module 200 is fixed by the cage 106, and heat generated by the optical module 200 is transferred to the cage 106 and then diffused through the heat sink 107. After the optical module 200 is inserted into the cage 106, the electrical port of the optical module 200 is connected with an electrical connector inside the cage 106, so that the optical module 200 establishes a bi-directional electrical signal connection with the optical network terminal 100. Furthermore, the optical port of the optical module 200 is connected to the optical fiber 101, so that the optical module 200 establishes a bi-directional electrical signal connection with the optical fiber 101.

Fig. 3 is a block diagram of an optical module according to some embodiments, and fig. 4 is an exploded block diagram of an optical module according to some embodiments. As shown in fig. 3 and 4, the optical module 200 includes a housing (shell), a circuit board 300 disposed in the housing, a light emitting device 400, and a light receiving device 500.

The housing includes an upper housing 201 and a lower housing 202, the upper housing 201 being capped on the lower housing 202 to form the above-described housing having two openings 204 and 205; the outer contour of the housing generally presents a square shape.

In some embodiments, the lower housing 202 includes a bottom plate 2021 and two lower side plates 2022 disposed on both sides of the bottom plate and perpendicular to the bottom plate; the upper housing 201 includes a cover 2011, and the cover 2011 is covered on two lower side plates 2022 of the lower housing 202 to form the housing.

In some embodiments, the lower housing 202 includes a bottom plate 2021 and two lower side plates 2022 disposed on both sides of the bottom plate and perpendicular to the bottom plate; the upper housing 201 includes a cover 2011, and two upper side plates disposed on two sides of the cover and perpendicular to the cover, and the two upper side plates are combined with two lower side plates 2022 to cover the upper housing 201 on the lower housing 202.

The direction in which the two openings 204 and 205 are connected may be the same as the longitudinal direction of the optical module 200 or may be different from the longitudinal direction of the optical module 200. Illustratively, opening 204 is located at the end of light module 200 (right end of fig. 3) and opening 205 is also located at the end of light module 200 (left end of fig. 3). Alternatively, the opening 204 is located at the end of the light module 200, while the opening 205 is located at the side of the light module 200. The opening 204 is an electrical port, and the golden finger 301 of the circuit board 300 extends out of the electrical port 204 and is inserted into an upper computer (such as the optical network terminal 100); the opening 205 is an optical port configured to access the external optical fiber 101 such that the optical fiber 101 connects the light emitting device 400 and the light receiving device 500 inside the optical module 200.

The circuit board 300, the light emitting device 400, the light receiving device 500 and other devices are conveniently installed in the upper and lower cases 201 and 202 in a combined assembly mode, and the upper and lower cases 201 and 202 form package protection for the devices. In addition, when the circuit board 300, the light emitting device 400, the light receiving device 500, and the like are assembled, the disposition of the positioning member, the heat dissipating member, and the electromagnetic shielding member of these devices is facilitated, which is advantageous for the automated production.

In some embodiments, the upper housing 201 and the lower housing 202 are generally made of metal materials, which is beneficial to electromagnetic shielding and heat dissipation.

In some embodiments, the optical module 200 further includes an unlocking member 203 located on an outer wall of the housing, and the unlocking member 203 is configured to achieve 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.

Illustratively, the unlocking member 203 is located outside of the two lower side plates 2022 of the lower housing 202, and includes an engagement member that mates with a cage of an upper computer (e.g., the cage 106 of the optical network terminal 100). When the optical module 200 is inserted into the cage of the upper computer, the optical module 200 is fixed in the cage of the upper computer by the clamping component of the unlocking component 203; when the unlocking member 203 is pulled, the engaging member of the unlocking member 203 moves along with the unlocking member, so as to change the connection relationship between the engaging member and the host computer, so as to release the engagement relationship between the optical module 200 and the host computer, and thus the optical module 200 can be pulled out from the cage of the host computer.

The circuit board 300 includes circuit traces, electronic components and chips, which are connected together by the circuit traces according to a circuit design to realize functions such as power supply, electrical signal transmission, and grounding. The electronic components may include, for example, capacitors, resistors, transistors, metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). The chips may include, for example, a micro control unit (Microcontroller Unit, MCU), a laser driver chip, a transimpedance amplifier (Transimpedance Amplifier, TIA), a limiting amplifier (Limiting Amplifier), a clock data recovery chip (Clock and Data Recovery, CDR), a power management chip (Power Management Chip), a digital signal processing (Digital Signal Processing, DSP) chip.

The circuit board 300 is generally a hard circuit board, and the hard circuit board can also realize a bearing function due to the relatively hard material, for example, the hard circuit board can stably bear the electronic components and chips; the hard circuit board can also be inserted into an electrical connector in the cage of the host computer.

The circuit board 300 further includes a gold finger 301 formed on an end surface thereof, the gold finger 301 being composed of a plurality of pins independent of each other. The circuit board 300 is inserted into the cage 106 and is conductively connected to the electrical connectors within the cage 106 by the gold fingers 301. The golden finger 301 may be disposed on a surface of only one side of the circuit board 300 (for example, an upper surface shown in fig. 4), or may be disposed on surfaces of both upper and lower sides of the circuit board 300, so as to adapt to a situation where the number of pins is large. The golden finger 301 is configured to establish electrical connection with an upper computer to achieve power supply, grounding, I2C signal transfer, data signal transfer, and the like.

Of course, flexible circuit boards may also be used in some optical modules. The flexible circuit board is generally used in cooperation with the rigid circuit board to supplement the rigid circuit board.

Fig. 5 is a block diagram of an optical module with a housing and an unlocking member removed, and fig. 6 is a block diagram of a light emitting device in an optical module, according to some embodiments. As shown in fig. 5 and 6, the optical module 200 further includes a first fiber optic adapter 600, a second fiber optic adapter 700, a first internal optical fiber 800, and a second internal optical fiber 900. The first optical fiber adapter 600 is connected to the light emitting device 400 through the first internal optical fiber 800, and the second optical fiber adapter 700 is connected to the light receiving device 500 through the second internal optical fiber 900.

In some embodiments, the first fiber optic adapter 600 includes a first sub-fiber optic adapter 601 and a second sub-fiber optic adapter 602. The first internal optical fiber 800 includes a first sub internal optical fiber 801 and a second sub internal optical fiber 802; the first sub-fiber optic adapter 601 is connected to the light emitting device 400 by a first sub-internal optical fiber 801 and the second sub-fiber optic adapter 602 is connected to the light emitting device 400 by a second sub-internal optical fiber 802.

The light receiving device 500 includes a first sub light receiving device 501 and a second sub light receiving device 502; the second internal optical fiber 900 includes a third sub internal optical fiber 901 and a fourth sub internal optical fiber 902; the second fiber optic adapter 700 includes a third sub-fiber optic adapter 701 and a fourth sub-fiber optic adapter 702. The third sub-fiber adapter 701 is connected to the first sub-light receiving device 501 through a third sub-internal optical fiber 901, and the fourth sub-fiber adapter 702 is connected to the second sub-light receiving device 502 through a fourth sub-internal optical fiber 902.

The light emitting device 400 and the light receiving device 500 are both provided on a surface of the circuit board 300 close to the upper case 201 (hereinafter, the surface will be referred to as a front surface, and a surface of the circuit board 300 close to the lower case 202 will be referred to as a rear surface), and the first sub light receiving device 501 and the second sub light receiving device 502 are respectively located on both sides of the light emitting device 400.

The light emitting device 400 includes a base 410, a laser 420, a collimator lens 430, a translating prism 440, optical combiners 4510 and 4520, optical isolators 4610 and 4620, optical couplers 4710 and 4720, and a semiconductor refrigerator (Thermo Electric Cooler, TEC) 480 disposed on the base 410.

The base 410 has a mounting surface and a bottom surface. The laser 420, collimating lens 430, translating prism 440, optical combiners 4510 and 4520, optical isolators 4610 and 4620, optical couplers 4710 and 4720, and semiconductor refrigerator 480 are all mounted on the mounting surface of the base 410. The bottom surface of the base 410 is the surface opposite to its mounting surface.

The laser 420 includes a laser chip 421 and a spacer 422. The laser chip 421 has a cathode and an anode, and the spacer 422 includes an insulating and heat conductive layer and a metal layer including a ground line and a signal line. The cathode of the laser chip 421 may be fixed to the ground line by welding or conductive glue, etc., so as to be electrically connected to the ground line. The anode of the laser chip 421 may be electrically connected to the signal line through a connection line. By applying voltages to the cathode and anode of the laser chip 421 respectively to the ground line and the signal line, the laser chip 421 can emit a laser beam parallel to the front surface of the circuit board 300.

The semiconductor refrigerator 480 is disposed on a mounting surface of the base 410, and the laser 420 is disposed on a surface of the semiconductor refrigerator 480 remote from the base 410. The semiconductor refrigerator 480 is configured to conduct heat generated by the laser chip 421 to the mount 410, and to be conducted out of the optical module 200 through the mount 410 and the housing of the optical module 200. In some embodiments, the semiconductor refrigerator 480 includes first and second heat exchange surfaces disposed opposite each other, and a plurality of heat conductive pillars between the first and second heat exchange surfaces. The first heat exchange surface and the second heat exchange surface are connected by a plurality of heat conductive posts. In some embodiments, the plurality of heat conductive pillars may be arranged in an array, which may be made of a semiconductor material. For example, the first heat exchange surface of the semiconductor refrigerator 480 is provided on the mounting surface of the mount 410, and the laser 420 is provided on the second heat exchange surface of the semiconductor refrigerator 480. In some embodiments, however, semiconductor refrigerator 480 may be omitted.

The collimator lens 430 is capable of adjusting the divergent laser beam generated by the laser chip 421 into a parallel laser beam, i.e., a collimated beam. In some embodiments, collimating lens 430 may also be omitted.

The translating prism 440 is an rhombic prism having a first reflecting surface 441 and a second reflecting surface 442. The first reflecting surface 441 and the second reflecting surface 442 each are capable of changing the propagation direction of the laser beam, for example, turning the propagation direction of the laser beam by 90 °. In some embodiments, the first reflecting surface 441 reflects a path of laser beam parallel to the front surface of the circuit board 300 emitted by the laser chip 421, so that the path of laser beam continues to propagate in a direction perpendicular to the front surface of the circuit board 300; the second reflecting surface 442 reflects the path of the laser beam perpendicular to the front surface of the circuit board 300 so that the path of the laser beam propagates again in a direction parallel to the front surface of the circuit board 300.

One laser beam emitted by the laser 420 is converted into a collimated beam by the collimator lens 430. The collimated light beams are reflected twice by the translation prism 440, then sequentially pass through the optical combiners 4510 and 4520 and the optical isolators 4610 and 4620, enter the optical fiber couplers 4710 and 4720, and couple the laser light beams to the first optical fiber adapter 600 by the optical fiber couplers 4710 and 4720, so that the emission of one path of optical signals is realized.

When the optical module 200 is an optical module with a high transmission rate, such as an 800G (signal transmission rate is 800 Gbit/s) optical module, 8 optical signal transmission channels need to be encapsulated in a housing of the optical module 200, and the signal transmission rate of each optical signal transmission channel is 100Gbit/s. The light emitting device 400 thus includes 8 lasers 420 to achieve emission of 8 optical signals; the light receiving device 500 includes 8 light receivers to achieve reception of 8 optical signals. For example, the first sub light receiving device 501 includes 4 light receivers to achieve reception of 4 optical signals; the second sub light-receiving device 502 includes 4 light receivers to achieve reception of 4 optical signals.

Based on this, the light emitting device 400 includes 8 lasers 420, 8 collimating lenses 430, and 1 translating prism 440. The lasers 420 and the collimator lenses 430 are in one-to-one correspondence. Each laser 420 emits a path of laser beam, each collimating lens 430 converts the path of laser beam into a collimated beam, the collimated beam emitted by each collimating lens 430 is transmitted to a translating prism 440, and the translating prism 440 reflects the straight beam to change the transmission direction and position of the laser beam. It should be noted that, the light emitting device 400 is not limited to include 1 translating prism 440, and may include a plurality of translating prisms 440, and each translating prism 440 corresponds to one or more collimating lenses 430. The light emitting device 400 is not limited to include 8 collimator lenses 430, but may include 4 (1 collimator lens 430 for every 2 lasers 420), 2 (1 collimator lens 430 for every 4 lasers 420), or 1 collimator lens 430 (1 collimator lens 430 for all lasers 420).

Further, the optical combiners 4510 and 4520 include a first optical combiners 4510 and 4520, the optical isolators 4610 and 4620 include a first optical isolator 4610 and a second optical isolator 4620, and the optical couplers 4710 and 4720 include a first optical coupler 4710 and a second optical coupler 4720. But is not limited thereto, the first optical combiner 4510 and the second optical combiner 4520 may be integrated as a single optical combiner, and the first optical isolator 4610 and the second optical isolator 4620 may be integrated as a single optical isolator. When the first optical multiplexer 4510 and the second optical multiplexer 4520 are integrated as a single optical multiplexer, the first optical fiber coupler 4710 and the second optical fiber coupler 4720 may be integrated as a single optical fiber coupler, and the first sub-optical fiber adapter 601 and the second sub-optical fiber adapter 602 may be integrated as a single optical fiber adapter.

The first optical multiplexer 4510 and the second optical multiplexer 4520 are disposed on the mounting surface of the base 410 in parallel. For example, the first optical multiplexer 4510 and the second optical multiplexer 4520 are disposed side by side on the mounting surface of the base 410 in a direction perpendicular to the light emission direction of the laser 420. The light input ends of the first optical combiner 4510 and the second optical combiner 4520 face the light output end of the translation prism 440, so that 8 laser beams parallel to the front surface of the circuit board 300 are respectively incident into the first optical combiner 4510 and the second optical combiner 4520. For example, 4 laser beams are incident on the first optical combiner 4510, and the first optical combiner 4510 combines the 4 laser beams into a first composite beam; the remaining 4 laser beams are incident into the second optical multiplexer 4520, and the second optical multiplexer 4520 synthesizes the remaining 4 laser beams into a second composite beam.

The first optical combiner 4510 includes 4 light inlets for receiving light of a plurality of wavelengths, each for receiving light of one wavelength. The light inlet is located at the light input end of the first optical combiner 4510 near the side of the translation prism 440. The first optical multiplexer 4510 further includes 1 light outlet for emitting light. The light outlet is located at the light input end of the side of the first optical combiner 4510 away from the translating prism 440.

Taking the first optical multiplexer 4510 to receive light with the wavelength of λ1, λ2, λ3 and λ4 as an example, the light with the wavelength of λ1 enters the first optical multiplexer 4510 through the first light inlet, and reaches the light outlet after being reflected by a plurality of (e.g. 6) different positions in the first optical multiplexer 4510 for a plurality of (e.g. 6) different times; light with wavelength lambda 2 enters the first optical multiplexer 4510 through the second optical inlet, and reaches the optical outlet after being reflected by a plurality of (e.g. 4) different positions in the first optical multiplexer 4510 for a plurality of times (e.g. 4 times); light with wavelength lambda 3 enters the first optical multiplexer 4510 through the third light inlet, and reaches the light outlet after being reflected for multiple times (for example, 2 times) at multiple (for example, 2) different positions in the first optical multiplexer 4510; light with wavelength lambda 4 enters the first optical multiplexer 4510 through the fourth light inlet, and reaches the light outlet directly without reflection. Thus, light with different wavelengths is input through different light inlets and output through the same light outlet through the first optical combiner 4510, and light with different wavelengths is further combined into a first composite beam.

The first light inlet is, for example, one of the 4 light inlets of the first optical multiplexer 4510, which is farthest from the second optical multiplexer 4520, and the fourth light inlet is, for example, one of the 4 light inlets of the first optical multiplexer 4510, which is closest to the second optical multiplexer 4520.

The second optical multiplexer 4520 includes 4 light inlets for receiving light of a plurality of wavelengths, each for receiving light of one wavelength. The light inlet is located at the light input end of the second optical multiplexer 4510 near the side of the translation prism 440. The second optical multiplexer 4520 further includes 1 light outlet for emitting light. The light outlet is located at the light input end of the side of the second optical multiplexer 4520 away from the translating prism 440.

Taking the second optical multiplexer 4520 to receive light with 4 wavelengths of λ5, λ6, λ7 and λ8 as an example, the light with the wavelength of λ5 enters the second optical multiplexer 4520 through the fifth light inlet, and reaches the light outlet after being reflected by a plurality of (e.g. 6) different positions in the second optical multiplexer 4520 for a plurality of (e.g. 6) different times; light with wavelength lambda 6 enters the second optical multiplexer 4520 through the sixth light inlet, and reaches the light outlet after being reflected for multiple times (for example, 4 times) at multiple (for example, 4) different positions in the second optical multiplexer 4520; light with the wavelength of lambda 7 enters the second optical multiplexer 4520 through the seventh light inlet, and reaches the light outlet after being reflected for multiple times (for example, 2 times) at multiple (for example, 2) different positions in the second optical multiplexer 4520; light with the wavelength of lambda 8 enters the second optical multiplexer 4520 through the eighth light inlet, and reaches the light outlet directly without being reflected. Thus, light with different wavelengths is input through different light inlets and output through the same light outlet through the second optical combiner 4520, and light with different wavelengths is further combined into a second composite beam.

Fig. 7 shows reflection positions and reflection times in the second optical multiplexer 4520 for 4 wavelengths of light, λ5, λ6, λ7, and λ8. Similarly, the reflection positions and the reflection times in the 4-wavelength light first optical multiplexer 4510 of λ1, λ2, λ3, and λ4 can be derived from fig. 7.

The fifth light inlet is, for example, one of the 4 light inlets of the second optical multiplexer 4520, which is farthest from the first optical multiplexer 4510, and the eighth light inlet is, for example, one of the 4 light inlets of the second optical multiplexer 4520, which is closest to the first optical multiplexer 4510.

Wavelength λ5 may be the same as or different from wavelength λ1, wavelength λ6 may be the same as or different from wavelength λ2, wavelength λ7 may be the same as or different from wavelength λ3, and wavelength λ8 may be the same as or different from wavelength λ4.

The optical input end of the first optical fiber coupler 4710 is optically 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 sub-fiber adapter 601 via the first sub-internal optical fiber 801. In this way, the first composite beam output by the first optical combiner 4510 is coupled to the first sub-internal optical fiber 801 through the first optical fiber coupler 4710, and then transmitted to the first sub-optical fiber adapter 601 through the first sub-internal optical fiber 801, so as to implement emission of the first composite beam.

The optical input end of the second fiber coupler 4720 is optically coupled to the optical output end of the second optical combiner 4520, and the optical output end of the second fiber coupler 4720 is connected to the second sub-fiber adapter 602 via the second sub-internal optical fiber 802. In this way, the second composite beam output by the second optical combiner 4520 is coupled to the second sub-internal optical fiber 802 through the second optical fiber coupler 4720, and is transmitted to the second sub-optical fiber adapter 602 through the second sub-internal optical fiber 802, so as to implement emission of the second composite beam.

When a gap exists between the optical output end of the first optical combiner 4510 and the optical input end of the first optical fiber coupler 4710, and the first composite beam output by the first optical combiner 4510 is transmitted to the optical input end of the first optical fiber coupler 4710, the first composite beam is reflected at the optical input end of the first optical fiber coupler 4710, and the reflected beam may return to the laser 420 in the original path, so that the performance of the laser 420 is affected. To avoid this problem, a first optical isolator 4610 is disposed between the first optical combiner 4510 and the first optical fiber coupler 4710, and when the first composite beam emitted from the first optical combiner 4510 is reflected at the optical input end of the first optical fiber coupler 4710, the first optical isolator 4610 is configured to isolate the reflected beam and prevent the reflected beam from returning to the laser 420 along the original path. In some embodiments, the first optical isolator 4610 is omitted.

Similarly, there is a gap between the optical output end of the second optical combiner 4520 and the optical input end of the second optical fiber coupler 4720, when the second composite beam output by the second optical combiner 4520 is transmitted to the optical input end of the second optical fiber coupler 4720, the second composite beam is reflected at the optical input end of the second optical fiber coupler 4720, and the reflected beam may return to the laser 420 in the original path, so that the performance of the laser 420 is affected. To avoid this problem, a second optical isolator 4620 is disposed between the second optical combiner 4520 and the second optical fiber coupler 4720, and the second optical isolator 4620 is configured to isolate the reflected light beam from returning to the laser 420 along the original path when the second composite light beam emitted from the second optical combiner 4520 is reflected at the optical input end of the second optical fiber coupler 4720. In some embodiments, the second optical isolator 4620 is omitted.

As shown in fig. 7, in some embodiments, the second fiber coupler 4720 includes a ferrule 4721, a focusing lens 4722, and a single mode fiber flange 4723. The sleeve 4721 is sleeved outside the focusing lens 4722 and the single-mode fiber flange 4723, the second sub-internal optical fiber 802 is inserted in the single-mode fiber flange 4723, the light incident surface of the focusing lens 4722 faces the second optical isolator 4620, the light emergent surface faces the single-mode fiber flange 4723, the second composite beam output by the second optical combiner 4520 is transmitted to the focusing lens 4722 through the second optical isolator 4620, and the focusing lens 4722 converges the second composite beam to the second sub-internal optical fiber 802 inserted in the single-mode fiber flange 4723.

The focusing lens 4722 is a cylindrical lens, and the outer diameter dimensions of the cylindrical lens and the single-mode fiber flange 4723 are slightly smaller than the inner diameter dimension of the sleeve 4721, so as to ensure the coupling degree of the focusing lens 4722 and the single-mode fiber flange 4723. When the focusing lens 4722 and the single-mode fiber flange 4723 are inserted into the sleeve 4721, in order to improve the coupling degree of the focusing lens 4722 and the single-mode fiber flange 4723, the focusing lens 4722 and the single-mode fiber flange 4723 can be moved only axially, so that the operation is convenient.

In order to facilitate the second composite light beam transmitted through the second optical isolator 4620 to enter the focusing lens 4722, the focusing lens 4722 protrudes out of the sleeve 4721, so that the distance between the light incident surface of the focusing lens 4722 and the light emergent surface of the second optical isolator 4620 is reduced, and the structure is more compact.

As shown in fig. 10A and 10B, the first fiber coupler 4710 includes a ferrule 4711, a focusing lens 4712, and a single mode fiber flange 4713. The structure and function of the first optical fiber coupler 4710 are the same as those of the second optical fiber coupler 4720, and will not be described again.

Along with the smaller and smaller size of the optical module, the higher the signal transmission rate, the simpler the internal structure of the optical module is required to be so as to reasonably layout the optical components and the electronic components. In the optical module 200 in some embodiments of the present disclosure, the optical combiner is used to combine multiple light beams in multiple (e.g., 4-way and 8-way) optical signal transmission channels into one composite light beam, which simplifies the internal structure of the optical module 200 and is beneficial to the optical module to realize high-speed signal transmission.

Fig. 8 is a block diagram of a circuit board in an optical module according to some embodiments. As shown in fig. 8, 9A and 9B, the circuit board 300 includes a mounting hole 320, the base 410 of the light emitting device 400 is mounted on the front surface of the circuit board 300, the mounting surface of the base 410 faces the front surface of the circuit board 300, and the laser 420, the collimator lens 430 and the translating prism 440 in the light emitting device 400 are embedded in the mounting hole 320. This allows the laser 420 and the collimator lens 430 to be positioned on the back side of the circuit board 300, the optical combiners 4510 and 4520, the optical isolators 4610 and 4620, and the optical couplers 4710 and 4720 to be positioned on the front side of the circuit board 300, and the translating prism 440 to be positioned partially on the back side of the circuit board 300 and partially on the front side of the circuit board 300 after the circuit board 300 is mounted with the light emitting device 400.

As shown in fig. 10A and 10B, a plurality of lasers 420 emit laser beams, respectively, which are parallel to the back surface of the circuit board 300; the plurality of collimating lenses 430 convert the plurality of laser beams emitted from the plurality of lasers 420 into a plurality of collimated beams, the plurality of collimated beams are transmitted to the translating prism 440, and the first reflecting surface 441 and the second reflecting surface 442 of the translating prism 440 reflect the plurality of collimated beams, thereby reflecting the plurality of laser beams located at the rear side of the circuit board 300 to the front side of the circuit board 300. Thereafter, the first optical combiner 4510 combines the 4 collimated light beams into a first composite light beam, and the second optical combiner 4520 combines the remaining 4 collimated light beams into a second composite light beam.

The first reflecting surface 441 of the translating prism 440 faces the plurality of collimating lenses 430, is located at the back side of the circuit board 300, and is configured to reflect the plurality of collimated light beams parallel to the back side of the circuit board 300 into a plurality of collimated light beams perpendicular to the circuit board 300; the second reflecting surface 442 of the translating prism 440 faces the first reflecting surface 441, is located on the front side of the circuit board 300, and is configured to reflect a plurality of collimated light beams perpendicular to the circuit board 300 into a plurality of collimated light beams parallel to the front side of the circuit board 300.

The optical components (optical combiners 4510 and 4520, optical isolators 4610 and 4620, optical couplers 4710 and 4720, etc.) behind the plurality of collimating lenses 430 are all positioned on the front side of the circuit board 300 and maintain a proper gap with the front side of the circuit board 300 by the translating action of the translating prism 440 on the plurality of collimated light beams. In this way, the position conflict between the optical components and the circuit board 300 is avoided, so that the area of the mounting hole 320 in the circuit board 300 can be reduced as much as possible, the arrangement area of the electronic components on the circuit board 300 is increased, and the wiring of the circuit board 300 is easier.

The mounting surface of the base 410 is directed to the front surface of the circuit board 300 and the plurality of lasers 420 are mounted on the back surface side of the circuit board 300 in such a manner that the bottom surface of the light emitting device 400 is close to the upper case 201 and away from the lower case 202, which is called a flip-chip manner of the light emitting device 400. When the light emitting device 400 is flip-chip mounted on the front surface of the circuit board 300, the pads 422 in the laser 420 are flush with the back surface of the circuit board 300, so that the connection lines between the ground and signal lines on the pads 422 and the circuit traces on the back surface of the circuit board 300 are minimized to ensure excellent high-frequency signal transmission performance.

Fig. 11A and 11B are electrical connection diagrams of a circuit board and a light emitting device in a light module according to some embodiments. As shown in fig. 11A and 11B, the digital signal processing chip 310 is located on the front surface of the circuit board 300, and is configured to transmit a high-frequency signal to the laser 420 of the light emitting device 400, provide a signal for a laser beam emitted by the laser 420, and modulate the laser beam into an optical signal. For this purpose, the circuit board 300 includes a high-frequency signal line 330 and a via 340. The via 340 is located at an output pad of the digital signal processing chip 310, and the via 340 penetrates through the front and back surfaces of the circuit board 300. The high frequency signal line 330 is located in the via 340, and the high frequency signal line 330 is electrically connected to the output pad of the digital signal processing chip 310 through the via 340 to transmit a high frequency signal.

Since the pads 422 in the laser 420 are flush with the back side of the circuit board 300, the high frequency signal lines 330 are routed along the back side of the circuit board 300 through the vias 340 and then electrically connected to the laser 420 by a wire bonding process. That is, one end of the high frequency signal line 330 is electrically connected to the output pad of the digital signal processing chip 310, and the other end is located on the back surface of the circuit board 300 and is electrically connected to the laser 420 through a wire bonding process. After passing through the digital signal processing chip 310, the high-frequency signal transmitted from the golden finger 301 of the circuit board 300 is transmitted to the laser 420 via the high-frequency signal line 330, so that the laser 420 emits an optical signal.

The circuit board 300 includes a plurality of vias 340, and the plurality of vias 340 are disposed on a side of the mounting hole 320 near the gold finger 301, and each via 340 corresponds to one laser 420, such that the high-frequency signal line 330 passing through each via 340 is connected to the corresponding laser 420.

The circuit board 300 further includes a dc signal line 302, the dc signal line 302 being located on the back side of the circuit board 300. The dc signal line 302 is electrically connected to the laser 420, and transmits a bias current to drive the laser 420 to emit light. The direct current signal wire 302 may be electrically connected to the laser 420 from the side of the mounting hole 320 on the circuit board 300, which is far away from the gold finger 301, through a wire bonding process, and the laser 420 emits light after receiving the bias current transmitted by the direct current signal wire 302. And the high frequency signal transmitted through the high frequency signal line 330 is transmitted to the laser 420, the laser 420 modulates the high frequency signal into the light beam, so that the laser 420 generates an optical signal.

The direct current signal line 302 may also be connected to the laser 420 from the other side of the mounting hole 320, i.e., the direct current signal line 302 connecting the laser 420 and the high frequency signal line 330 are located on different sides of the mounting hole 320. This prevents interference between the high frequency signal and the direct current signal, and also makes the transmission path of the direct current signal shorter, avoiding overcrowding of wiring in the circuit board 300.

Fig. 12A is a block diagram of a base in an optical module according to some embodiments, and fig. 12B is a block diagram of another angle of the base in an optical module according to some embodiments. As shown in fig. 12A and 12B, the mounting surface of the base 410 includes a first mounting surface 4110, a second mounting surface 4120, and a third mounting surface 4130 that are connected in order to carry the laser 420, the collimator lens 430, the translating prism 440, the optical combiners 4510 and 4520, the optical isolators 4610 and 4620, the optical fiber couplers 4710 and 4720, and the semiconductor refrigerator 480. The second mounting surface 4120 is recessed from the first mounting surface 4110 toward the bottom surface of the base 410, and the third mounting surface 4130 is recessed from the second mounting surface 4120 toward the bottom surface of the base 410. The third mounting surface 4130 has a smaller dimension from the bottom surface of the base 410 than the second mounting surface 4120, and the second mounting surface 4120 has a smaller dimension from the bottom surface of the base 410 than the first mounting surface 4110, such that the first mounting surface 4110, the second mounting surface 4120, and the third mounting surface 4130 form a stepped surface.

In some embodiments, the first mounting surface 4110, the second mounting surface 4120, and the third mounting surface 4130 are all parallel to the bottom surface of the base 410. The base 410 further includes two baffles 4111, where the two baffles 4111 are respectively located at two sides of the first mounting surface 4110 parallel to the light emitting direction of the laser 420, and the two baffles 4111 extend in a direction away from the bottom surface of the base 410, so that when the light emitting device 400 is mounted on the circuit board 300, the two baffles 4111 abut against the front surface of the circuit board 300. The laser 420 and the collimator lens 430 are fixed to a first mounting surface 4110. The second mounting surface 4120 is opened in a direction perpendicular to the light emitting direction of the laser 420 to facilitate fixing the translation prism 440 to the second mounting surface 4120; the third mounting surface 4130 is opened in a direction perpendicular to the light emitting direction of the laser 420 and is also opened in a direction along the light emitting direction of the laser 420 to facilitate fixing of the optical combiners 4510 and 4520, the optical isolators 4610 and 4620, and the optical fiber couplers 4710 and 4720 to the third mounting surface 4130.

As such, the mounting height of the laser 420 and the collimator lens 430 on the base 410 is greater than the mounting height of the translating prism 440, and the mounting height of the translating prism 440 is greater than the mounting heights of the Yu Guangge wave devices 4510 and 4520, the optical isolators 4610 and 4620, and the optical fiber couplers 4710 and 4720. After the laser 420, the collimator lens 430, and the translating prism 440 are embedded in the mounting hole 320 of the circuit board 300, the laser 420 and the collimator lens 430 are positioned on the back side of the circuit board 300, the optical combiners 4510 and 4520, the optical isolators 4610 and 4620, and the optical fiber couplers 4710 and 4720 are positioned on the front side of the circuit board 300, and a part of the translating prism 440 is positioned on the back side of the circuit board 300 and another part is positioned on the front side of the circuit board 300.

A semiconductor refrigerator 480 is placed on the first mounting surface 4110, and a plurality of lasers 420 are provided on the semiconductor refrigerator 480. The laser 420 includes a laser chip 421 and a pad 422, the laser chip 421 being located on the pad 422, the pad 422 being disposed on a semiconductor refrigerator 480. A collimator lens 430 corresponding to each laser 420 is also provided on the semiconductor refrigerator 480, and the collimator lens 430 is provided in the light emitting direction of the laser 420.

In some embodiments, when the light emitting device includes 8 lasers 420 and 8 collimating lenses 430, the 8 lasers 420 are disposed side by side in a direction perpendicular to the respective light emitting directions, and the 8 collimating lenses 430 are also disposed side by side in a direction perpendicular to the light emitting directions of the lasers 420, so that the 8 lasers 420 emit 8 light beams of different wavelengths.

The dimensions of the 8 lasers 420 in the respective light-emitting directions may be the same, so that the dimensions of the sides of the 8 collimator lenses 430 from the first mounting surface 4110 away from the second mounting surface 4120 are the same. However, the size of the 8 lasers 420 along the respective light emitting directions may be different. In the light emitting direction of the lasers 420, a distance that a part of the lasers 420 (first lasers) extends from the side of the first mounting surface 4110 away from the second mounting surface 4120 is smaller than a distance that another part of the lasers 420 (second lasers) extends from the side of the first mounting surface 4110 away from the second mounting surface 4120, so that the 8 lasers 420 are fixed to the semiconductor refrigerator 480 in such a manner that the first lasers and the second lasers are spaced apart (for example, short, long, short, long).

In this case, the sizes of the sides of the 8 collimator lenses 430 from the first mounting surface 4110 away from the second mounting surface 4120 are also different so that the plurality of collimator lenses 430 do not interfere with each other due to the flow of glue when assembled. In this way, the pitch of the multiple collimated light beams can be reduced to reduce the outline size of the base 410, particularly the size of the base 410 in the direction perpendicular to the light emitting direction of the laser 420, so that the light emitting device 400 and the light receiving device 500 do not collide at the time of assembly.

In some embodiments, the dimension of the first mounting surface 4110 in a direction perpendicular to the light emitting direction of the laser 420 is slightly larger than the dimension of the second mounting surface 4120 in that direction, and the dimension of the second mounting surface 4120 in that direction substantially coincides with the dimension of the third mounting surface 4130 in that direction. When the plurality of lasers 420 are fixed to the first mounting surface 4110 side by side in a direction perpendicular to the respective light emitting directions, the wider first mounting surface 4110 can facilitate placement of the plurality of lasers 420, avoid a smaller distance between adjacent lasers 420, and thus can avoid crosstalk between the plurality of laser beams emitted by the plurality of lasers 420.

A translating prism 440 is disposed on the second mounting surface 4120. The translating prism 440 is vertically fixed on the second mounting surface 4120, and the first reflecting surface 441 of the translating prism 440 is far away from the second mounting surface 4120 and is close to the laser 420; the second reflective surface 442 of the translating prism 440 is proximate to the second mounting surface 4120. In this way, the laser beam 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 third mounting surface 4130 is provided with optical combiners 4510 and 4520, optical isolators 4610 and 4620, and optical couplers 4710 and 4720. The first optical combiner 4510 and the second optical combiner 4520 are arranged side by side in a direction perpendicular to the light emission direction of the laser 420, the first optical isolator 4610 and the second optical isolator 4620 are also arranged side by side in the direction, the first optical fiber coupler 4710 and the second optical fiber coupler 4720 are also arranged side by side in the direction, and the optical combiner, the optical isolator, and the optical fiber coupler are arranged along the light emission direction of the laser 420.

In some embodiments, the dimensions of the third mounting surface 4130 in the direction perpendicular to the light emitting direction of the laser 420 are consistent along the light emitting direction of the laser 420, and the dimensions of the third mounting surface 4130 in the direction perpendicular to the light emitting direction of the laser 420 are smaller than the dimensions of the first and second light combiners 4510 and 4520 arranged side by side in the direction, so that when the first and second light combiners 4510 and 4520 are arranged side by side on the third mounting surface 4130 in the direction perpendicular to the light emitting direction of the laser 420, the side of the first light combiners 4510 away from the second light combiners 4520 and the side of the second light combiners 4520 away from the first light combiners 4510 protrude from the first mounting surface 4110, the dimensions of the base 410 in the direction perpendicular to the light emitting direction of the laser 420 can be reduced, and the cost can be saved.

The semiconductor refrigerator 480, the laser 420, the collimator lens 430, the translating prism 440, the optical combiners 4510 and 4520, the optical isolators 4610 and 4620, and the optical couplers 4710 and 4720 are fixed on the base 410 by the first mounting surface 4110, the second mounting surface 4120, and the third mounting surface 4130 having a stepped shape to form a mounting height difference between the laser 420, the collimator lens 430 and the optical combiners 4510 and 4520, the optical isolators 4610 and 4620, and the optical couplers 4710 and 4720, and to dispose the laser 420 and the collimator lens 430 having a relatively large mounting height on the back side of the circuit board 300 through the mounting hole 320 of the circuit board 300 and dispose the optical combiners 4510 and 4520, the optical isolators 4610 and 4620, and the optical couplers 4710 and 4720 having a relatively small mounting height on the front side of the circuit board 300, so that an overlapping region of the light emitting device 400 and the circuit board 300 in space can be reduced.

In assembling the light emitting device 400, the semiconductor refrigerator 480 is first mounted on the first mounting surface 4110, and the laser 420 is fixed on the semiconductor refrigerator 480; the translating prism 440 is then secured to the second mounting surface 4120; then, the optical combiners 4510 and 4520, the optical isolators 4610 and 4620, and the optical couplers 4710 and 4720 are independently fixed to the third mounting surface 4130 in the light emitting direction of the laser 420; finally, the collimating lens 430 is fixed on the first mounting surface 4110 in an active coupling manner along the light emitting direction of the laser 420. Active coupling means that the alignment lens 430 is mounted in a state that the laser chip 421 is energized and emits light, and simultaneously coupling efficiency in sub-internal optical fibers 801 and 802 is detected, and the position of the alignment lens 430 is optimized.

To reduce assembly effort, 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, the second optical fiber coupler 4720, the first sub-internal optical fiber 801, the second sub-internal optical fiber 802, the first sub-optical fiber adapter 601, and the second sub-optical fiber adapter 602 may also be assembled as a pre-assembly. First, the semiconductor refrigerator 480 is fixed on the first mounting surface 4110, and the laser 420 is fixed on the semiconductor refrigerator 480; the translating prism 440 is then secured to the second mounting surface 4120; the preassembly is then secured to the third mounting face 4130; finally, the collimating lens 430 is fixed on the first mounting surface 4110 in an active coupling manner along the light emitting direction of the laser 420, so as to optimize the position of the collimating lens 430.

After the semiconductor refrigerator 480, the laser 420, the collimator lens 430, the translation prism 440, the optical combiners 4510 and 4520, the optical isolators 4610 and 4620, and the optical couplers 4710 and 4720 are fixed to the base 410, the base 410 is reversely mounted on the front surface of the circuit board 300. That is, the bottom surface of the base 410 faces the upper housing 201, and the first mounting surface 4110, the second mounting surface 4120, and the third mounting surface 4130 of the base 410 face the front surface of the circuit board 300.

To secure the base 410 to the front surface of the circuit board 300, the base 410 further includes two first support columns 4140. Two first support columns 4140 are located at the end of the third mounting face 4130 remote from the second mounting face 4120. Two first support columns 4140 have openings therebetween through which two sub-inner optical fibers 801 and 802, respectively connected to the first and second fiber couplers 4710 and 4720, pass to connect with the corresponding sub-fiber adapters 601 and 602. The distance between the two first support columns 4140 in the direction perpendicular to the light emitting direction of the laser 420 is not greater than the dimension of the third mounting surface 4130 in that direction, such as the opposite sides of the two first support columns 4140 being flush with the side of the base 410.

Each first support column 4140 extends from the third mounting surface 4130 in a direction away from the bottom surface of the base 410. The base 410 further includes two first positioning pins 4141, where the two first positioning pins 4141 are respectively located on end surfaces of the two first support columns 4140 facing away from the third mounting surface 4130. The circuit board 300 includes a first positioning hole 360, and the first positioning hole 360 is disposed corresponding to the first positioning pin 4141.

In some embodiments, base 410 further includes a locating block 4150, locating block 4150 being located at one end of first mounting face 4110 remote from ion fiber optic adapters 601 and 602. The positioning block 4150 extends in a direction away from the bottom surface of the base 410 and protrudes from the first mounting surface 4110. The base 410 further includes two positioning projections 4151, and the two positioning projections 4151 are located on an end surface of the positioning block 4150 facing away from the first mounting surface 4110. The circuit board 300 includes a second positioning hole 370, and the second positioning hole 370 is disposed corresponding to the positioning protrusion 4151.

When the base 410 is reversely mounted on the front surface of the circuit board 300, the first support column 4140 and the positioning block 4150 of the base 410 are in contact with the front surface of the circuit board 300, the first positioning pin 4141 on the first support column 4140 is inserted into the first positioning hole 360 on the circuit board 300, and the positioning protrusion 4151 on the positioning block 4150 is inserted into the second positioning hole 370 on the circuit board 300. Thereby fixing the base 410 to the circuit board 300 and embedding the laser 420 and the collimator lens 430 provided on the first mounting surface 4110 and the translating prism 440 provided on the second mounting surface 4120 into the mounting hole 320 of the circuit board 300.

Fig. 13 is a heat dissipation channel diagram of an optical module according to some embodiments. As shown in fig. 13, after the light emitting device 400 is reversely mounted to the front surface of the circuit board 300, the bottom surface of the base 410 of the light emitting device 400 faces the upper case 201 and contacts the upper case 201. After the laser 420 in the light emitting device 400 is connected to the digital signal processing chip 310 on the front side of the circuit board 300 through the high frequency signal line 330, the laser 420 generates an optical signal under the driving of the bias current and the high frequency signal, so that the laser 420 generates heat. However, the light emission performance of the laser 420 is easily affected by temperature, and thus the laser 420 needs to operate within a certain fixed temperature range. Placing it on the semiconductor refrigerator 480 can ensure the operating temperature of the laser 420, but in this way heat is transferred from the laser 420 to the semiconductor refrigerator 480, which needs to be conducted away to ensure the refrigeration efficiency of the semiconductor refrigerator 480.

The heat generated by the laser 420 is conducted to the base 410 through the semiconductor refrigerator 480 to maintain the temperature of the laser 420. In order to improve the heat dissipation performance of the optical module, the base 410 may be made of tungsten copper or other metal materials with good thermal conductivity, and the mass of the base 410 and the area of the bottom surface thereof are properly increased, so that the heat generated by the operation of the laser 420 can be conducted to the upper housing 201 through the base 410, and the heat dissipation effect of the laser 420 is effectively improved.

The laser 420 is disposed on the first mounting surface 4110 of the base 410 by the semiconductor refrigerator 480, and the mounting area of the laser 420 on the base 410 is smaller than the contact area between the base 410 and the upper housing 201, so that the heat dissipation efficiency of the laser 420 can be improved.

To ensure that the laser operates at a certain fixed temperature, some embodiments increase the mass of the base 410 and the contact area of the base 410 with the upper housing 201, such that the contact area of the base 410 with the upper housing 201 is greater than the mounting area of the laser 420 on the base 410. The heat generated by the laser 420 is thus transferred to the semiconductor refrigerator 480, the semiconductor refrigerator 480 transfers the heat to the base 410, and the base 410 transfers the heat to the upper case 201, thereby transferring the heat generated by the laser 420 to the outside of the optical module 200.

The optical module 200 further includes a first thermally conductive gasket. To facilitate heat conduction from the base 410 to the upper case 201, a first heat-conducting gasket is disposed between the bottom surface of the base 410 and the inner side surface of the upper case 201. Thus, the heat of the base 410 can be transferred to the first heat-conducting pad, and the first heat-conducting pad transfers the heat to the upper housing 201, so as to effectively improve the heat dissipation effect. In some embodiments, the first thermally conductive pad is a thermally conductive adhesive. The heat conducting glue can adhere the base 410 to the inner side surface of the upper shell 201 and conduct the heat of the base 410 to the upper shell 201.

In some embodiments, the primary heat source of the optical module is a digital signal processing chip 310 in addition to the laser 420. The side of the digital signal processing chip 310 facing away from the circuit board 300 is in contact with the upper case 201. In this manner, heat generated by the operation of the digital signal processing chip 310 may be conducted to the upper case 201 to conduct heat generated by the digital signal processing chip 310 to the outside of the optical module 200.

The optical module 200 also includes a second thermally conductive gasket. To facilitate heat conduction from the dsp 310 to the upper housing 201, a second thermally conductive pad is disposed between the dsp 310 and an inner side of the upper housing 201. Thus, the heat generated by the digital signal processing chip 310 is transferred to the second heat conductive pad, and the second heat conductive pad transfers the heat to the upper housing 201, so as to effectively improve the heat dissipation effect.

Fig. 14A is a cross-sectional view of a monitoring optical path of a light detector in an optical module according to some embodiments, and fig. 14B is a top view of a monitoring optical path of a light detector in an optical module according to some embodiments. As shown in fig. 14A and 14B, the laser 420 emits a laser beam under the drive of a bias current and a high frequency signal transmitted by the circuit board 300, and in order to monitor the emitted light power of the laser 420, the circuit board 300 further includes a photodetector 350, and the photodetector 350 is disposed on the back surface of the circuit board 300. The photodetector 350 is located at a side of the mounting hole 320 away from the golden finger 301, and the photosensitive surface of the photodetector 350 faces the light emitting direction of the laser 420. The light detector 350 is configured to collect forward light emitted by the laser 420 and send the collected data to the circuit board 300 to enable monitoring of forward light output of the laser 420.

When the light detector 350 is attached to the side of the mounting hole 320 far from the golden finger 301, the photosensitive surface of the light detector 350 is flush with the inner sidewall of the mounting hole 320, so as to facilitate positioning of the light detector 350; the photosensitive surface of the photodetector 350 may also protrude from the inner sidewall of the mounting hole 320 to reduce the distance between the photosensitive surface of the photodetector 350 and the first reflecting surface 441, so that the photodetector 350 can collect as much laser beam as possible that passes through the first reflecting surface 441.

In some embodiments, a small portion of the collimated light beam is directed through the first reflective surface 441 of the translating prism 440 and toward the photosensitive surface of the light detector 350 by utilizing the light transmission characteristics of the first reflective surface 441 such that the light detector 350 can receive a portion of the light beam to obtain the emitted light power of the laser 420.

For example, the first reflecting surface 441 of the translating prism 440 faces the light emitting direction of the laser 420, and is configured to split one laser beam generated by the laser 420 into two beams, one beam (typically accounting for 95% of the total power of the laser) is reflected by the first reflecting surface 441 to the second reflecting surface 442, so as to reflect the laser beam from the back side of the circuit board 300 to the front side of the circuit board 300, and the other beam is incident on the photosensitive surface of the photodetector 350 through the first reflecting surface 441, and receives the laser beam emitted by the laser 420 through the photosensitive surface.

When the photodetector 350 is disposed on the back surface of the circuit board 300, the central axis of the photosensitive surface in the photodetector 350 coincides with the central axis of the laser 420, and the photodetector 350 is mounted on the back surface of the circuit board 300 by a surface mount technology (Surface Mounted Technology, SMT) such that the light beam transmitted through the first reflecting surface 441 is injected into the photodetector 350 as much as possible.

In some embodiments, the circuit board 300 includes 8 photodetectors 350, each photodetector 350 being disposed in correspondence with one of the lasers 420. Thus, each photodetector 350 collects a portion of the laser light beam emitted from one laser 420 and transmitted through the first reflecting surface 441, and measures the forward light output of the corresponding laser 420.

The light detector 350 receives parallel light with a certain area, so that the accuracy of the assembly position of the light detector 350 is low, and the assembly is easier. After the light transmission range of the first reflecting surface 441 in the translating prism 440 is aligned with the photosensitive surface of the photodetector 350, the photodetector 350 can collect the laser beam transmitted through the first reflecting surface 441.

The photodetector 350 has a cathode and an anode. When the photodetector 350 is fixed on the back surface of the circuit board 300, the cathode may be fixed on the grounding metal layer of the circuit board 300 by soldering or conductive adhesive bonding. The anode of the photodetector 350 is disposed opposite to the cathode, and the anode is electrically connected to the circuit board 300 through a wire bonding process, thereby electrically connecting the photodetector 350 to the circuit board 300.

Fig. 15A is an assembly structure diagram of a circuit board and a light receiving device in an optical module according to some embodiments. As shown in fig. 15A and 5, the light receiving device 500 of the 800G (signal transmission rate of 800 Gbit/s) light module in some embodiments of the present disclosure includes two sub light receiving devices 501 and 502, and the first sub light receiving device 501 and the second sub light receiving device 502 may be symmetrically disposed at both sides of the mounting hole 320 of the circuit board 300 in a direction perpendicular to the light emitting direction of the laser 420. The first sub light receiving device 501 is connected to the third sub optical fiber adapter 701 through a third internal optical fiber 901, and an optical signal received by the third sub optical fiber adapter 701 from outside the optical module 200 is transmitted to the first sub light receiving device 501 through the third internal optical fiber 901, so as to implement the reception of a third composite beam; the second sub-light receiving device 502 is connected to the fourth sub-fiber adapter 702 through a fourth internal optical fiber 902, and the optical signal received by the fourth sub-fiber adapter 702 from outside the optical module 200 is transmitted to the second sub-light receiving device 502 through the fourth internal optical fiber 902, so as to implement the reception of the fourth composite light beam.

Fig. 15B is a block diagram of a light receiving device in an optical module according to some embodiments, and fig. 15C is a partial light path diagram of a light receiving device in an optical module according to some embodiments. As shown in fig. 15B and 15C, the first sub-light receiving device 501 has the same structure as the second sub-light receiving device 502, and the second sub-light receiving device 502 includes a support plate 5021, and a light collimator 5022, a light demultiplexer 5023, a lens array 5024, and a reflecting prism 5025 provided on the support plate 5021. The combination of the light collimator 5022, the light demultiplexer 5023, the lens array 5024 and the reflecting prism 5025 can also be referred to as the light receiver as described above. A fourth internal optical fiber 902 connected to the fourth sub-optical fiber adapter 702 is inserted into the optical collimator 5022, and an optical signal from the outside of the optical module 200 is transmitted to the optical demultiplexer 5023 through the optical collimator 5022, and then the fourth composite beam is demultiplexed into 4 laser beams through the optical demultiplexer 5023; the 4 paths of laser beams are respectively converged to a reflecting prism 5025 through a lens array 5024; the 4 laser beams are reflected at the reflecting surface of the reflecting prism 5025, reflect the laser beams parallel to the front surface of the circuit board 300 into laser beams perpendicular to the front surface of the circuit board 300, and make the reflected laser beams enter the receiving detector 380 on the circuit board 300 to realize light receiving.

The light collimator 5022 comprises a ferrule 50221, a single-mode fiber flange 50222 and a collimating lens 50223, and the single-mode fiber flange 50222 and the collimating lens 50223 are inserted into the ferrule 50221. The fourth internal optical fiber 902 is inserted into the single mode fiber flange 50222 and positioned opposite the collimating lens 50223. The collimating lens 50223 is configured to convert the light beam transmitted from the outside of the optical module 200 by the fourth internal optical fiber 902 into a collimated light beam.

The light incident surface of the optical demultiplexer 5023 faces the light emergent surface of the collimating lens 50223 and is configured to demultiplex one collimated beam output by the collimating lens 50223 into 4 laser beams, thereby separating the beams including a plurality of different wavelengths. The optical demultiplexer 5023 outputs 4 light beams of different wavelengths, and the 4 light beams of different wavelengths are respectively injected into corresponding lenses in the lens array 5024 to converge the 4 light beams of different wavelengths onto a reflecting surface of the reflecting prism 5025. The reflecting prism 5025 is disposed right above the receiving detectors 380 of the circuit board 300, and the reflecting prism 5025 reflects 4 paths of light beams with different wavelengths into the corresponding receiving detectors 380, respectively, and converts the light signals into electrical signals through the receiving detectors 380.

The transimpedance amplifier of the circuit board 300 is connected with the receiving detector 380 through a circuit wire, the receiving detector 380 firstly converts the received optical signal into a high-frequency current signal, and then the high-frequency current signal is transmitted to the transimpedance amplifier; the transimpedance amplifier converts the high-frequency current signal into a high-frequency voltage signal, amplifies the high-frequency voltage signal, and transmits the high-frequency voltage signal to the digital signal processing chip 310 via the high-frequency signal line 330. The digital signal processing chip 310 extracts the data in the high-frequency voltage signal, and transmits the data to the optical network terminal 100 through the golden finger 301.

In some embodiments of the present disclosure, one end of the transimpedance amplifier is connected to the reception detector 380 through a circuit trace, and the other end is connected to the digital signal processing chip 310 through a high-frequency signal line 330. The high-frequency current signal converted by the receiving detector 380 is converted into a high-frequency voltage signal by a transimpedance amplifier and amplified, and then transmitted to the digital signal processing chip 310 for processing via the high-frequency signal line 330.

In some embodiments, the light receiving device may also employ an optical demultiplexing device based on arrayed waveguide grating (Arrayed Waveguide Grating, AWG) technology to achieve the same optical demultiplexing effect.

In some embodiments, the first sub light receiving device 501 and the second sub light receiving device 502 are mounted in the same manner, and the mounting manner of the second sub light receiving device 502 is described as an example. The light collimator 5022, the lens array 5024 of the light demultiplexer 5023 and the reflecting prism 5025 are sequentially and fixedly arranged on the supporting plate 5021 to form a pre-assembly. The pre-assembly is then secured to the circuit board 300 in an active coupling manner, thereby ensuring that the reflective prism 5025 in the pre-assembly couples the multiplexed optical signal into the receiving detector 380.

When the second sub light receiving device 502 is fixed on the circuit board 300, a gap between the support plate 5021 and the circuit board 300 is filled with glue. So that there is a height difference between the light collimator 5022, the light demultiplexer 5023, the lens array 5024, the reflecting prism 5025 and the receiving detector 380 of the circuit board 300 in the second sub-light receiving device 502 after the mounting is completed.

The first sub light receiving device 501 and the second sub light receiving device 502 are mounted on the front surface of the circuit board 300 in a symmetrical structure, so that the optical module 200 forms a complementary structure in layout, position conflict between the devices is avoided, the overall structure is compact, and the mounting is convenient.

In the optical module provided by some embodiments of the present disclosure, the area of the mounting hole in the circuit board is reduced by adopting the translation prism, so that the layout design of the circuit board is easier; in addition, the integrated optical components, such as an optical multiplexer, an optical isolator, an optical fiber coupler and the like, are adopted, so that the assembly difficulty of the optical components is simplified; the light emitting device adopts a flip-chip assembly structure, so that the overall size of the light emitting device is reduced, and meanwhile, the heat dissipation characteristic of the light emitting device is greatly improved; the interval arrangement of a plurality of lasers with different sizes in the light emitting device greatly reduces the distance between adjacent lasers and reduces the size of the light emitting device in the light emitting direction of the lasers.

Note that the present disclosure is not limited to the examples described above. That is, the above examples may also be appropriately changed. Representative modifications will be described below. In the following description of the modification, only the portions different from the above examples will be described. In the above examples and modifications, the same or equivalent components are denoted by the same reference numerals. Therefore, in the following description of the modification, the description of the above-described example is correspondingly referred to as long as there is no technical contradiction or no particular additional description regarding the constituent elements having the same reference numerals as the above-described example.

Fig. 16A is a structural view of a light emitting device in a light module according to some modifications, and fig. 16B is a structural view of a base in the light emitting device shown in fig. 16A. As shown in fig. 16A, the light emitting device 400 includes a laser 420, a collimator lens 430, a translating prism 440, a converging lens 490, an optical isolator 460, a fiber coupler 470, and a semiconductor refrigerator 480. The light emitting device 400 omits the optical combiners 4510 and 4520,8 to transmit the optical signals to the outside of the optical module 200 through the 8 internal optical fibers 800. The converging lens 490 converges the collimated light beam passing through the translating prism 440 to form a converging light beam. The converging beam is better able to enter the fiber coupler 470.

As shown in fig. 16A and 16B, to fix the base 410 on the front surface of the circuit board 300, the base 410 omits the first support 4140 and includes two second support columns 4160. Two second support columns 4160 are located at the end of the third mounting face 4130 remote from the second mounting face 4120. There is an opening between the two second support columns 4160 through which 8 internal optical fibers 800 connected to the fiber couplers 470 are connected to corresponding fiber optic adapters. The distance between the two second support columns 4160 in the direction perpendicular to the light emitting direction of the laser 420 is greater than the dimension of the third mounting surface 4130 in that direction to facilitate the passage of 8 internal optical fibers 800 through the openings.

As shown in fig. 16A, each second support column 4160 extends from the third mounting surface 4130 in a direction away from the bottom surface of the base 410. The base 410 further includes two second positioning pins 4161, where the two second positioning pins 4161 are respectively located on end surfaces of the two second support columns 4160 facing away from the third mounting surface 4130. The circuit board 300 includes a first positioning hole 360, and the first positioning hole 360 is disposed corresponding to the second positioning pin 4161.

When the base 410 is reversely mounted to the front surface of the circuit board 300, the second support column 4160 and the positioning block 4150 of the base 410 are in contact with the front surface of the circuit board 300, the second positioning pin 4161 on the second support column 4160 is inserted into the first positioning hole 360 on the circuit board 300, and the positioning protrusion 4151 on the positioning block 4150 is inserted into the second positioning hole 370 on the circuit board 300. Thereby fixing the base 410 to the circuit board 300 and embedding the laser 420 and the collimator lens 430 provided on the first mounting surface 4110 and the translating prism 440 provided on the second mounting surface 4120 into the mounting hole 320 of the circuit board 300.

Fig. 17A is a structural view of a light emitting device in a light module according to another modification, and fig. 17B is a structural view of a base in the light emitting device shown in fig. 17A. As shown in fig. 17A and 17B, to fix the base 410 on the front surface of the circuit board 300, the base 410 omits the first support column 4140 and includes a support block 4170. The support block 4170 extends from the third mounting surface 4130 in a direction away from the bottom surface of the base 410. The support block 4170 is located at an end of the third mounting surface 4130 remote from the second mounting surface 4120, and a side of the support block 4170 remote from the second mounting surface 4120 is flush with a side of the base 410 remote from the first mounting surface 4110.

The support block 4170 has two through holes 4171, and the two through holes 4171 are arranged side by side in a direction perpendicular to the light emitting direction of the laser 420, and penetrate the support block 4170 along the light emitting direction of the laser 420. The first fiber coupler 4710 and the second fiber coupler 4720 are inserted into two through holes 4171 on the supporting block 4170 to fix the first fiber coupler 4710 and the second fiber coupler 4720 on the base 410 through the supporting block 4170.

In some embodiments, the size of the support block 4170 in the direction perpendicular to the light emitting direction of the laser 420 is not greater than the size of the third mounting surface 4130 in this direction, so that the base 410 is easy to process and saves manufacturing costs.

When the base 410 is reversely mounted to the front surface of the circuit board 300, the supporting block 4170 and the positioning block 4150 of the base 410 are in contact with the front surface of the circuit board 300, and the positioning protrusion 4151 of the positioning block 4150 is inserted into the second positioning hole 370 of the circuit board 300. Thereby fixing the base 410 to the circuit board 300 and embedding the laser 420 and the collimator lens 430 provided on the first mounting surface 4110 and the translating prism 440 provided on the second mounting surface 4120 into the mounting hole 320 of the circuit board 300.

Fig. 18A is an assembly structure diagram of a circuit board, a light emitting device, and a light receiving device in an optical module according to still another modification, and fig. 18B is a structure diagram of the optical module shown in fig. 18A with the light emitting device omitted. As shown in fig. 18A and 18B, in order to reduce the size of the circuit board 300 in a direction perpendicular to the light emitting direction of the laser 420, the light emitting device 400 may be reversely mounted on the front surface of the circuit board 300, the first sub light receiving device 501 may be mounted on the front surface of the circuit board 300 at one side of the light emitting device 400, and the second sub light receiving device 502 may be mounted on the rear surface of the circuit board 300 with the first sub light receiving device 501 and the second sub light receiving device 502 being symmetrically disposed.

In this case, the third optical fiber adapter 701 and the fourth optical fiber adapter 702 are also arranged side by side in the thickness direction of the base 410, and the third optical fiber adapter 701 is connected to the first sub-light receiving device 501 through the third internal optical fiber 901 to achieve reception of the third composite light beam. The fourth fiber optic adapter 702 is connected to the second sub-light receiving device 502 by a fourth internal optical fiber 902 to effect reception of a fourth composite light beam.

Fig. 18C is a cross-sectional view of an assembled structure of a circuit board and a light receiving device in an optical module according to some embodiments. As shown in fig. 18C, the first sub light receiving device 501 and the second sub light receiving device 502 are symmetrically disposed on the front and back sides of the circuit board 300. The first sub light receiving device 501 disposed on the front surface of the circuit board 300 is connected to the third sub optical fiber adapter 701 through the third internal optical fiber 901, so that the light beam from the outside of the optical module 200 is transmitted to the first sub light receiving device 501 through the third internal optical fiber 901, and the third composite light beam is demultiplexed into 4-way light beams via the optical demultiplexer 5023. The 4 paths of light beams are reflected to a receiving detector 380 arranged on the front surface of the circuit board 300 through a reflecting prism 5025, the light signals are converted into high-frequency current signals through the receiving detector 380, the high-frequency current signals are transmitted to a transimpedance amplifier 390, the high-frequency current signals are converted into high-frequency voltage signals through the transimpedance amplifier 390 and then transmitted to a digital signal processing chip 310, and then the digital signal processing chip 310 extracts data in the high-frequency voltage signals.

The second photonic light receiving device 502 disposed at the rear surface of the circuit board 300 is connected to the fourth sub-optical fiber adapter 702 through the fourth internal optical fiber 902 such that the light beam from the outside of the optical module 200 is transmitted to the second sub-light receiving device 502 through the fourth internal optical fiber 902, and the fourth composite light beam is demultiplexed into 4-way light beams via the optical demultiplexer 5023. The 4 paths of light beams are reflected to a receiving detector 380 arranged on the back surface of the circuit board 300 through a reflecting prism 5025, the light signals are converted into high-frequency current signals through the receiving detector 380, the high-frequency current signals are transmitted to a transimpedance amplifier 390, the high-frequency current signals are converted into high-frequency voltage signals through the transimpedance amplifier 390 and then transmitted to a digital signal processing chip 310, and then the digital signal processing chip 310 extracts data in the high-frequency voltage signals.

In some embodiments, after the second sub light receiving device 502 is disposed on the back surface of the circuit board 300, a via is disposed at the input pad of the digital signal processing chip 310, the via penetrating the front and back surfaces of the circuit board 300. The high frequency signal line connected to the input pad of the digital signal processing chip 310 extends to the rear surface of the circuit board 300 through the via hole and is connected to the transimpedance amplifier 390 to transmit the high frequency signal on the circuit board 300 from the front surface to the rear surface of the circuit board 300, so that the high frequency signal is transmitted to the transimpedance amplifier 390 located at the rear surface of the circuit board 300.

Fig. 19A is a structural view of a light emitting device in an optical module according to still another modification, and fig. 19B is a structural view of a base in the optical module shown in fig. 19A. It should be noted that the light emitting device 400 and the light receiving device 500 described above are applicable to not only 800G optical modules but also 400G (signal transmission rate is 400 Gbit/s) optical modules. The 400G optical module encapsulates 4 paths of optical signal transmission channels in a shell, and the signal transmission rate of each optical signal transmission channel is 100Gbit/s. The 400G optical module can realize excellent high-frequency performance, optical performance and heat dissipation characteristic in a narrow space, and has low structural complexity and high producibility. Therefore, the 400G optical module can realize mass production and reduce cost.

As shown in fig. 19A and 19B, in some embodiments, the light emitting device 400 in the 400G optical module includes a semiconductor refrigerator 480, 4 lasers 420, 4 collimating lenses 430, 1 translating prism 440, 1 optical combiner 450, 1 optical isolator 460, and 1 fiber coupler 470. It should be noted that the number of the optical multiplexer 450, the optical isolator 460 and the optical fiber coupler 470 is only one example, and does not limit the present disclosure.

The 4 lasers 420 are arranged in one-to-one correspondence with the 4 collimating lenses 430, each laser 420 emits a path of laser beam, and each collimating lens 430 converts the path of laser beam into a collimated beam. The collimated light beam emitted from each collimating lens 430 is transmitted to a translating prism 440, and the collimated light beam is reflected by the translating prism 440 to change the transmission direction of the laser beam.

The light emitting device 400 is reversely mounted on the front surface of the circuit board 300. The semiconductor refrigerator 480 is fixed on the base 410, and 4 lasers 420 and 4 collimator lenses 430 are fixed on the semiconductor refrigerator 480 and located on the back side of the circuit board 300 through the mounting holes 320. A portion of the translation prism 440 is located at the back side of the circuit board 300 through the mounting hole 320, and another portion of the translation prism 440 is located at the front side of the circuit board 300. The optical multiplexer 450, the optical isolator 460 and the fiber coupler 470 are all located on the front side of the circuit board 300.

The 4 lasers 420 emit 4 laser beams, respectively, which are all parallel to the back surface of the circuit board 300; the 4 laser beams are respectively converted into 4 collimated beams by 4 collimating lenses 430, and the 4 collimated beams are transmitted to a translation prism 440; the translation prism 440 reflects the 4 laser beams located on the back side of the circuit board 300 to the front side of the circuit board 300.

The base 410 has a boss 4180, and the boss 4180 extends from the third mounting surface 4130 in a direction away from the bottom surface of the base 410. The first mounting surface 4110 and the second mounting surface 4120 are provided on the boss 4180. In some embodiments, the first mounting surface 4110 is recessed from the surface of the boss 4180 distal from the bottom surface of the base 410 toward the bottom surface of the base 410 to facilitate securing the semiconductor refrigerator 480 to the first mounting surface 4110 and then mounting the laser 420 to the semiconductor refrigerator 480.

The second mounting surface 4120 is recessed from the surface of the boss 4180 remote from the bottom surface of the base 410 toward the bottom surface of the base 410 and closer to the bottom surface of the base 410 than the first mounting surface 4110 to facilitate securing the translating prism 440 to the second mounting surface 4120. The first reflective surface 441 of the translating prism 440 is distal to the second mounting surface 4120 and proximate to the laser 420, and the second reflective surface 442 of the translating prism 440 is proximate to the second mounting surface 4120. In this manner, the laser beam 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 multiplexer 450, the optical isolator 460, and the optical fiber coupler 470 are sequentially disposed on the third mounting surface 4130.

In some embodiments, the dimension of the first mounting surface 4110 in a direction perpendicular to the light emitting direction of the lasers 420 is slightly larger than the dimension of the second mounting surface 4120 in that direction, so that 4 lasers 420 are conveniently arranged side by side on the first mounting surface 4110 in a direction perpendicular to the light emitting direction of the lasers 420. The dimension of the third mounting surface 4130 in the direction perpendicular to the light emitting direction of the laser 420 coincides with the dimension of the boss 4180 in this direction. In order to match the 4 lasers 420 on the first mounting surface 4110, the size of the optical multiplexer 450 in the direction perpendicular to the light emitting direction of the lasers 420 is smaller than the size of the third mounting surface 4130 in this direction.

In some embodiments, the base 410 further includes two third support columns 4190, the two third support columns 4190 being located at an end of the third mounting face 4130 remote from the second mounting face 4120. There is an opening between the two third support columns 4190 through which fiber couplers 470 connect with corresponding fiber optic adapters. The distance between the two third support columns 4190 in the direction perpendicular to the light emitting direction of the laser 420 is not greater than the dimension of the third mounting surface 4130 in that direction, such as the opposite sides of the two third support columns 4190 being flush with the side of the base 410.

Each third support column 4190 extends from the third mounting face 4130 in a direction away from the bottom face of the base 410. The base 410 further includes two third positioning pins 4191, where the two third positioning pins 4191 are located on end surfaces of the two third support columns 4190 facing away from the third mounting surface 4130, respectively. The third positioning pins 4191 are provided corresponding to the first positioning holes 360 on the circuit board 300.

To facilitate mounting the base 410 on the circuit board 300, the base 410 further includes two fourth positioning pins 4181. The two fourth positioning pins 4181 are located on the end face of the boss 4180 facing away from the first mounting face 4110. The fourth positioning pin 4181 is provided corresponding to the second positioning hole 370 on the circuit board 300.

When the base 410 is reversely mounted on the circuit board 300, the boss 4180 and the two third support columns 4190 of the base 410 are in contact with the front surface of the circuit board 300. The two fourth positioning pins on the boss 4180 are respectively inserted into the two second positioning holes 370 of the circuit board 300, and the two third positioning pins 4191 on the two third support columns 4190 are respectively inserted into the two first positioning holes 360 of the circuit board 300.

Fig. 20A is a structural view of a light emitting device in an optical module according to still another modification, and fig. 20B is a structural view of a base in the optical module shown in fig. 20A. As shown in fig. 20A and 20B, the base 410 is a square base including a recess 41010. The recess 41010 is recessed toward the bottom surface of the chassis 410 to form a first mounting surface 4110, a second mounting surface 4120, and a third mounting surface 4130. The base 410 further includes a securing hole 41011, the securing hole 41011 extending toward the fiber optic adapter to pass through the recess 41010. The optical fiber coupler 470 is inserted into the fixing hole 41011.

The semiconductor refrigerator 480 is provided on the first mounting surface 4130 within the recess 41010, 4 lasers 420 are provided on the semiconductor refrigerator 480, 4 collimator lenses 430 corresponding to the 4 lasers 420 are also provided on the semiconductor refrigerator 480, and the collimator lenses 430 are provided in the light emitting direction of the lasers 420.

The translating prism 440 is disposed on the second mounting surface 4120 within the recess 41010, and the first reflective surface 441 of the translating prism 440 is distal from the second mounting surface 4120 and is proximate to the laser 420; the second reflective surface 442 of the translating prism 440 is proximate to the second mounting surface 4120. In this manner, the translation prism 440 reflects the laser beam located on the back side of the circuit board 300 to the front side of the circuit board 300.

The optical combiner 450 and the optical isolator 460 are sequentially disposed on the third mounting surface 4130 in the groove 41010, and the 4 laser beams reflected by the translation prism 440 are combined into one composite beam by the optical combiner 450, and the composite beam is injected into the optical fiber coupler 470 through the optical isolator 460, so as to realize light emission.

In some embodiments, the dimension of the first mounting surface 4110 in a direction perpendicular to the light emitting direction of the lasers 420 is slightly larger than the dimension of the second mounting surface 4120 in that direction, so that 4 lasers 420 are conveniently arranged side by side on the first mounting surface 4110 in a direction perpendicular to the light emitting direction of the lasers 420. The dimension of the third mounting surface 4130 in the direction perpendicular to the light emitting direction of the laser 420 coincides with the dimension of the second mounting surface 4120 in this direction. Along the light-emitting direction of the laser 420, the size of the base 410 in a direction perpendicular to the light-emitting direction of the laser 420 is uniform.

The dimension of the third mounting surface 4130 in the direction perpendicular to the light emitting direction of the laser 420 is the same as the dimension of the groove 41010 in this direction, and the optical multiplexer 450 is embedded in the groove 41010, so that the dimension of the optical multiplexer 450 in the direction perpendicular to the light emitting direction of the laser 420 can be identical to the dimension of the third mounting surface 4130 in this direction.

In the optical module provided in some embodiments of the present disclosure, the light emitting device 400 is reversely assembled on the circuit board 300 such that the pads 422 in the laser 420 are flush with the back surface of the circuit board 300, thereby minimizing connection lines between the ground lines and the signal lines on the pads 422 and the circuit traces on the back surface of the circuit board 300 to ensure excellent high frequency signal transmission performance. In addition, such an arrangement also reduces the size of the mounting holes 320 of the circuit board 300 in order to increase the arrangement area of the electronic components of the circuit board 300.

The foregoing is merely a specific embodiment of the disclosure, but the protection scope of the disclosure is not limited thereto, and any person skilled in the art who is skilled in the art will recognize that changes or substitutions are within the technical scope of the disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

An optical module, comprising:

a housing including an upper housing and a lower housing;

a circuit board located between the upper and lower cases, the circuit board having a front face facing the upper case and a rear face facing the lower case, the circuit board including mounting holes penetrating the front and rear faces;

a light emitting device mounted on the circuit board, the light emitting device comprising:

a base mounted on a front surface of the circuit board, the base having a mounting surface facing the front surface and a bottom surface facing the upper housing, the bottom surface facing the upper housing;

the laser is arranged on the mounting surface, penetrates through the mounting hole and extends out of the back surface of the circuit board;

a translating prism mounted on the mounting surface, the translating prism passing through the mounting hole such that a portion thereof is located on the back side of the circuit board and another portion thereof is located on the front side of the circuit board, the translating prism being configured to translate a laser beam emitted from the laser on the back side of the circuit board to the front side of the circuit board;

and the optical fiber coupler is configured to transmit the laser beam translated by the translation prism to the front side of the circuit board to the outside of the optical module.
The light module of claim 1, wherein the translating prism comprises:

a first reflecting surface far away from the mounting surface and facing the laser, wherein the first reflecting surface is configured to reflect a laser beam which is emitted by the laser and is parallel to the back surface of the circuit board, so that the laser beam propagates along a direction perpendicular to both the front surface and the back surface of the circuit board;

and a second reflecting surface, which is close to the mounting surface and faces the optical fiber coupler, wherein the second reflecting surface is configured to reflect the laser beam perpendicular to the front surface and the back surface of the circuit board, so that the laser beam propagates along the direction parallel to the front surface of the circuit board.
The optical module of claim 1 or 2, wherein the mounting surface of the chassis comprises:

a first mounting surface on which the laser is mounted;

a second mounting surface recessed from the first mounting surface toward a bottom surface of the base, the translating prism being mounted on the second mounting surface;

and a third mounting surface recessed from the second mounting surface toward the bottom surface of the chassis, the optical fiber coupler being mounted on the third mounting surface.
A light module according to any one of claims 1 to 3, wherein the light emitting device comprises a plurality of lasers each emitting a beam of laser light, the plurality of lasers being arranged side by side in a direction perpendicular to the direction of light emission of the plurality of lasers;

the light emitting device further comprises at least one optical combiner mounted on the mounting surface of the base and between the translating prism and the optical fiber coupler, configured to combine the multiple laser beams reflected by the translating prism into at least one combined beam, and transmit the at least one combined beam to the optical fiber coupler.
The optical module of claim 4, wherein the plurality of lasers are configured to emit multiple laser beams of different wavelengths; the light emitting device further includes:

a first optical combiner configured to combine a part of the laser beams of the plurality of laser beams reflected by the translation prism into a first combined beam;

the second optical multiplexer is arranged side by side with the first optical multiplexer along the direction perpendicular to the light emitting directions of the plurality of lasers and is configured to combine the rest laser beams in the multi-path laser beams reflected by the translation prism into a second composite beam;

A first fiber coupler optically coupled to the first optical combiner and configured to couple the first composite beam to a first sub-fiber adapter through a first sub-internal fiber;

and a second optical fiber coupler optically coupled to the second optical combiner and disposed side-by-side with the first optical fiber coupler in a direction perpendicular to the light exiting directions of the plurality of lasers, configured to couple the second composite light beam to a second sub-fiber adapter through a second sub-internal optical fiber.
The optical module of claim 4 or 5, wherein the plurality of lasers includes at least one first laser and at least one second laser;

in the light emitting directions of the lasers, the distance that the first laser extends from the side edge of the base, which is close to the lasers, is smaller than the distance that the second laser extends from the same side edge;

the plurality of lasers are arranged side by side in a direction perpendicular to the light emitting direction of the plurality of lasers in a manner of spacing the first lasers and the second lasers.
The optical module of claim 1, wherein the laser comprises a laser chip and a spacer carrying the laser chip; after the light emitting device is mounted on the front side of the circuit board, the spacer is flush with the back side of the circuit board.
The optical module of claim 7, wherein the circuit board further comprises: the digital processing chip, the high-frequency signal line and the via hole;

the digital processing chip is fixed on the front surface of the circuit board and is positioned at one side of the mounting hole;

the via hole is positioned at the output bonding pad of the digital processing chip and penetrates through the front surface and the back surface of the circuit board;

the high-frequency signal wire is positioned in the via hole, one end of the high-frequency signal wire penetrates through the via hole and is electrically connected with the output bonding pad of the digital processing chip, and the other end of the high-frequency signal wire is electrically connected with the laser along the back surface of the circuit board.
The optical module of claim 8, wherein the circuit board further comprises a direct current signal line; the direct current signal wire is positioned on the back surface of the circuit board and is electrically connected with the laser;

the direct current signal line and the high frequency signal line are positioned on different sides of the mounting hole.
The optical module of claim 8, wherein the circuit board further comprises a photodetector disposed on a back surface of the circuit board and on a side of the mounting hole away from the digital processing chip, a photosensitive surface of the photodetector facing a light-emitting direction of the laser;

And part of light in the laser beam emitted by the laser device is transmitted through the translation prism and is emitted to the photosensitive surface of the optical detector, so that the optical detector can monitor the emitted light power of the laser device.
The optical module according to any one of claims 1 to 6, further comprising a light receiving device comprising a first sub light receiving device and a second sub light receiving device;

a third sub-internal optical fiber connected with a third sub-optical fiber adapter transmits a third beam of composite light from outside the optical module to the first sub-light receiving device, and a fourth sub-internal optical fiber connected with a fourth sub-optical fiber adapter transmits a fourth beam of composite light from outside the optical module to the second sub-light receiving device;

the first or second sub light receiving device includes an optical demultiplexer which demultiplexes the third or fourth composite light beam into multiple laser light beams and makes the multiple laser light beams incident on a receiving detector on the circuit board.
The optical module of claim 11, wherein,

the first sub light receiving device and the second sub light receiving device are mounted on the front surface of the circuit board and are respectively positioned at two sides of the light emitting device in a direction perpendicular to the light emitting direction of the laser; or,

The first sub light receiving device is mounted on the front surface of the circuit board, and the second sub light receiving device is mounted on the back surface of the circuit board.
The light module of any one of claims 1 to 6 wherein a bottom surface of the base is in thermally conductive contact with the upper housing.
The light module of any one of claims 1 to 6, wherein the base further comprises a first support post and a first dowel, or the base further comprises a second support post and a second dowel;

the first support column is positioned at one end of the mounting surface of the base far away from the laser and extends along the direction far away from the bottom surface of the base; the first locating pin is positioned on the end face of the first support column away from the bottom surface of the base;

the second support column is positioned at one end of the mounting surface of the base far away from the laser and extends along the direction far away from the bottom surface of the base; the second locating pin is positioned on the end face of the second support column away from the bottom surface of the base;

the circuit board further comprises a first positioning hole, and the first positioning hole is arranged corresponding to the first positioning pin or the second positioning pin.
The optical module of claim 14, wherein,

the base comprises two first support columns, an opening is arranged between the two first support columns, and an internal optical fiber connected with the optical fiber coupler passes through the opening and is connected with the optical fiber adapter; the distance between the two first support columns in the direction perpendicular to the light emergent direction of the laser is not greater than the dimension of the base in the direction, so that the opposite side surfaces of the two first support columns are level with the corresponding side surfaces of the base; or,

the base comprises two second support columns, an opening is arranged between the two second support columns, and an internal optical fiber connected with the optical fiber coupler passes through the opening and is connected with the optical fiber adapter; the distance between the two first support columns in the direction perpendicular to the light emergent direction of the laser is larger than the size of the base in the direction.
The optical module of claim 14, wherein,

the base also includes:

the positioning block is positioned on the mounting surface of the base, is close to one end of the laser and extends in a direction away from the bottom surface of the base; and

the positioning protrusion is positioned on the end face of the positioning block, which is far away from the bottom surface of the base;

The circuit board also comprises a second positioning hole, and the second positioning hole is arranged corresponding to the positioning protrusion.
The optical module according to any one of claims 1 to 6, wherein,

the base also includes:

the support block is positioned at one end of the mounting surface of the base far away from the laser and extends along the direction far away from the bottom surface of the base;

the through hole penetrates through the supporting block, and the optical fiber coupler is inserted into the through hole;

the positioning block is positioned on the mounting surface of the base, is close to one end of the laser and extends in a direction away from the bottom surface of the base; and

the positioning protrusion is positioned on the end face of the positioning block, which is far away from the bottom surface of the base;

the circuit board also comprises a second positioning hole, and the second positioning hole is arranged corresponding to the positioning protrusion.
The optical module according to any one of claims 1 to 6, wherein,

the base also includes:

the third support column is positioned at one end of the mounting surface of the base far away from the laser and extends along the direction far away from the bottom surface of the base;

the third locating pin is positioned on the end face of the third support column far away from the bottom surface of the base;

The boss is positioned at one end of the mounting surface of the base, which is close to the laser, and extends along the direction away from the bottom surface of the base; and

the fourth locating pin is positioned on the end face of the boss, which is far away from the bottom surface of the base;

the circuit board further includes:

the first positioning hole is arranged corresponding to the third positioning pin; and

the second positioning hole is arranged corresponding to the fourth positioning pin.
The optical module according to any one of claims 1 to 6, wherein,

the base also includes:

a groove which is concave towards the bottom surface of the base,

the fixing hole penetrates through the side wall of the groove, and the optical fiber coupler is inserted into the fixing hole;

the third locating pin is positioned on the end face of the groove, which is far away from the laser and the bottom surface of the base;

the fourth locating pin is positioned on the end face of the groove, which is close to the laser and far away from the bottom surface of the base;

the circuit board further includes:

the first positioning hole is arranged corresponding to the third positioning pin; and

the second positioning hole is arranged corresponding to the fourth positioning pin.
The optical module according to claim 1, wherein the optical module is an optical module with a signal transmission rate of 800Gbit/s, or the optical module is an optical module with a signal transmission rate of 400 Gbit/s.