Optical module and communication system

Abstract

An optical module, relating to the technical field of communications. The optical module comprises a housing (1), a printed circuit board assembly (2), and two optical assemblies (3). The housing (1) comprises two optical interfaces (11). The two optical assemblies (3) are respectively connected to the two optical interfaces (11) via two first optical fibers (4). Each optical assembly (3) comprises a transmitting optical sub-assembly (31) and a receiver optical sub-assembly (32) arranged in an insertion and removal direction (X) of the optical module. Each transmitting optical sub-assembly (31) is used to send a first combined optical beam via one optical interface (11), and each receiver optical sub-assembly (32) is used to receive a second combined optical beam via one optical interface (11). The two optical assemblies (3) are fixed to the printed circuit board assembly (2). The end of the printed circuit board assembly (2) away from the two optical interfaces (11) comprises two gold finger groups (21), and the two gold finger groups (21) are electrically connected to the two optical assemblies (3), respectively.

Description

Optical module and communication system

[0001] The present disclosure claims priority to Chinese Patent Application No. 202411266493.3, entitled "Optical module", filed on September 10, 2024, and Chinese Patent Application No. 202411397354.4, entitled "Optical module and communication system", filed on September 30, 2024, the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present disclosure relates to the field of communication technology, and in particular, to an optical module and a communication system. BACKGROUND

[0003] The communication system includes a center switch, a center optical module, an optical splitting and combining device, a plurality of access switches and a plurality of remote optical modules. The center optical module is plugged into the center switch and connected to the public optical interface of the optical splitting and combining device through an optical fiber. The plurality of remote optical modules are respectively plugged into the plurality of access switches and connected to a plurality of branch optical interfaces of the optical splitting and combining device through optical fibers.

[0004] In the optical transmission direction of the center optical module, the center optical module transmits a first combined light beam to the public optical interface of the optical splitting and combining device. The optical splitting and combining device splits the first combined light beam into a plurality of light beams and transmits them to the plurality of remote optical modules through the plurality of branch optical interfaces, respectively. In the optical receiving direction of the center optical module, the plurality of remote optical modules respectively transmit light beams to the plurality of branch optical interfaces of the optical splitting and combining device, and the optical splitting and combining device combines the plurality of light beams into a second combined light beam and transmits it to the center optical module through the public optical interface. The number of optical signals carried in the first combined light beam and the second combined light beam can be understood as the number of channels of the optical module.

[0005] Currently, the number of channels of the center optical module is small, so that the number of remote optical modules accessed by the center optical module is small, and high-density access of the remote optical modules cannot be achieved. Therefore, how to increase the number of channels of the optical module is a key technical problem. SUMMARY

[0006] The present disclosure provides an optical module and a communication system. The optical module provided by the present disclosure can have a larger number of channels. The technical solutions of the optical module and the communication system are described as follows.

[0007] In a first aspect, the present disclosure provides an optical module. The optical module comprises a housing, a printed circuit board assembly (PCBA), and two optical assemblies. The housing comprises two optical interfaces. The two optical assemblies are connected to the two optical interfaces by two first optical fibers respectively. The optical assembly comprises a transmitting optical sub-assembly (TOSA) and a receiver optical sub-assembly (ROSA) arranged along a plug direction of the optical module. Each TOSA is configured to transmit a first combined optical beam through one optical interface, and each ROSA is configured to receive a second combined optical beam through one optical interface. The two optical assemblies are fixed to the PCBA. The PCBA comprises two gold finger groups at an end away from the two optical interfaces, and the two gold finger groups are electrically connected to the two optical assemblies respectively.

[0008] In the present disclosure, the optical module can be referred to as a center optical module, a color optical module, a center color optical module, etc. The plug direction refers to the direction in which the optical module is inserted into a communication device and pulled out of the communication device. In addition to the plug direction, the present disclosure defines a first direction and a second direction, and the plug direction, the first direction, and the second direction are perpendicular to each other. Moreover, the first direction is parallel to the board surface of the PCBA, and the second direction is perpendicular to the board surface of the PCBA.

[0009] In the present disclosure, the optical module comprises two optical interfaces, two optical assemblies, and two gold finger groups. Compared with an optical module comprising one optical interface, one optical assembly, and one gold finger group, the optical module provided by the present disclosure has more channels. For example, compared with a conventional optical module, the number of channels of the optical module provided by the present disclosure can be doubled. In this way, it is beneficial to realize high-density access of a remote optical module.

[0010] In addition, by arranging the TOSA and the ROSA of the optical assembly along the plug direction of the optical module, on the one hand, the size of the optical module along the plug direction is fully utilized to arrange the optical assembly. Generally, the size of the optical module along the plug direction is the largest. On the other hand, the optical module is used to be plugged into an interface of a communication device, and the area of the interface is related to the size of the optical module along the first direction and the second direction, and is irrelevant to the size of the optical module along the plug direction. Therefore, even if the size of the optical module along the plug direction is increased to arrange the optical assembly, the number of optical modules that can be connected to the communication device will not be reduced.

[0011] In an implementation, the first combined light beam and the second combined light beam each covers at least eight working wavebands. Each gold finger group is configured to transmit at least eight transmission electrical signals to the light emitting assembly and transmit at least eight reception electrical signals generated by the light receiving assembly to the communication device. In this way, the optical module provided by the present disclosure has at least sixteen channels.

[0012] In an implementation, the first combined light beams transmitted by the light emitting assemblies of the two optical assemblies cover the same working wavebands and each covers eight coarse wavelength division multiplexer (CWDM) wavebands. The second combined light beams received by the light receiving assemblies of the two optical assemblies cover the same working wavebands and each covers another eight CWDM wavebands. Since the optical paths of the two optical assemblies are independent, even if the first combined light beams transmitted by the two light emitting assemblies cover the same working wavebands, they will not affect each other. Similarly, even if the second combined light beams received by the two light receiving assemblies cover the same working wavebands, they will not affect each other.

[0013] In an implementation, the light emitting assembly of each optical assembly is close to the gold finger group relative to the light receiving assembly. In this way, the light emitting assembly is close to the gold finger group, the electrical conduction path between the light emitting assembly and the gold finger group is short, and the attenuation of the transmission electrical signal is small, which is conducive to improving the signal quality of the first combined light beam emitted by the light emitting assembly and improving the reliability of the optical module.

[0014] In an implementation, the optical assembly further includes an optical fiber connector. The optical fiber connector is arranged between the light emitting assembly and the light receiving assembly along the plugging direction. The optical fiber connector is optically connected with the light emitting assembly and the light receiving assembly. The optical fiber connector is connected with one optical interface through a first optical fiber. The light emitting assembly is configured to transmit the first combined light beam through the optical fiber connector, and the light receiving assembly is configured to receive the second combined light beam through the optical fiber connector.

[0015] The technical solution provided by the present disclosure arranges the optical fiber connector between the light emitting assembly and the light receiving assembly, on the one hand, which facilitates the optical connection between the optical fiber connector and the light emitting assembly and the light receiving assembly. On the other hand, the optical fiber connector is far away from the optical interface, which is conducive to the splicing of the first optical fiber.

[0016] In an implementation, the light emitting assembly includes a light emitting assembly housing, a plurality of lasers, and a wavelength combining and separating assembly. The plurality of lasers and the wavelength combining and separating assembly are located inside the light emitting assembly housing. The wavelength combining and separating assembly is optically connected with the fiber connector and connects the light receiving assembly through the second optical fiber. In the light transmitting direction, the wavelength combining and separating assembly is configured to combine the light beams transmitted by the plurality of lasers into a first combined light beam and transmit the first combined light beam through the fiber connector. In the light receiving direction, the wavelength combining and separating assembly is configured to receive a second combined light beam through the fiber connector and transmit the second combined light beam to the light receiving assembly through the second optical fiber.

[0017] The technical solution provided by the present disclosure reduces the optical path of the optical assembly by locating the wavelength combining and separating assembly inside the light emitting assembly housing, compared with locating the wavelength combining and separating assembly independently from the light emitting assembly and the light receiving assembly, and realizes high density of the optical path of the optical assembly and reduces the size of the optical assembly in the plugging direction of the optical module.

[0018] In an implementation, the plurality of light beams transmitted by the plurality of lasers and the second combined light beam are transmitted on the same first optical fiber after one-time combining. That is, the plurality of light beams are combined into the first combined light beam, and the combining of the second combined light beam is also realized. The reduction of the combining level means further reduction of the optical path, which is more conducive to reducing the size of the optical assembly in the plugging direction of the optical module.

[0019] In an implementation, the wavelength combining and separating assembly includes a combining assembly and a sub-wavelength combining and separating assembly. In the light transmitting direction, the combining assembly is configured to combine the light beams transmitted by the plurality of lasers into a first combined light beam and transmit the first combined light beam to the sub-wavelength combining and separating assembly. The sub-wavelength combining and separating assembly is configured to transmit the first combined light beam through the fiber connector. In the light receiving direction, the sub-wavelength combining and separating assembly is configured to receive a second combined light beam through the fiber connector and transmit the second combined light beam to the light receiving assembly through the second optical fiber.

[0020] The technical solution provided by the present disclosure reduces the size of the optical assembly in the plugging direction of the optical module by locating the sub-wavelength combining and separating assembly inside the light emitting assembly housing, compared with locating the sub-wavelength combining and separating assembly in a separate component in the related art.

[0021] In an implementation, the light receiving assembly includes a plurality of detectors and a demultiplexer. The demultiplexer is arranged between the plurality of detectors and the light emitting assembly along the plug-in direction. The demultiplexer is connected to the multiplexer of the light emitting assembly through the second optical fiber. The demultiplexer is configured to receive the second multiplexed light beam through the second optical fiber, demultiplex the second multiplexed light beam into a plurality of light beams, and send the plurality of light beams to the plurality of detectors respectively. Since the demultiplexer is connected to the light emitting assembly through the second optical fiber, the second optical fiber does not need to bypass the plurality of detectors to be connected to the demultiplexer, which is conducive to the arrangement of the second optical fiber.

[0022] In an implementation, the circuit board assembly includes a main board. Two light assemblies are arranged on the same surface of the main board and along a first direction. The first direction is perpendicular to the plug-in direction and parallel to the main board. Two gold finger groups are arranged on the surface of the main board and along the first direction.

[0023] The technical solution provided by the present disclosure can avoid the light module being too long along the plug-in direction by arranging two light assemblies along the first direction. Generally, the size of the light module along the first direction is larger than the size along the second direction, so arranging two light assemblies along the first direction is also conducive to fully utilizing the space of the shell along the first direction to arrange two light assemblies. In addition, arranging two gold finger groups along the first direction facilitates the electrical connection between the two gold finger groups and the two light assemblies.

[0024] In an implementation, each gold finger group includes two sub-gold finger groups arranged on opposite surfaces of the main board respectively. Each sub-gold finger group includes two gold finger rows arranged along the plug-in direction. In this way, the gold fingers are arranged along the plug-in direction by fully utilizing the size of the main board, so that two gold finger groups can be arranged on the same main board, and the two gold finger groups have sixteen electrical channels.

[0025] In an implementation, the form of each gold finger group is consistent with the form of the gold fingers of a quad small form factor pluggable-double density (QSFP-DD) package. The form consistency means that the shape and arrangement of each gold finger of the gold finger group are consistent with the shape and arrangement of the gold fingers of the QSFP-DD package. The pin sequence of the gold finger group can be different from or the same as the pin sequence of the gold fingers of the QSFP-DD package.

[0026] The technical solution provided by the disclosure is that the form of the gold finger group is consistent with the form of the gold finger of the QSFP-DD package, so that the gold finger group can be connected to some existing QSFP-DD package electrical connectors, or only a few improvements are needed for the QSFP-DD package electrical connectors, for example, the pin device in the QSFP-DD package electrical connector is unchanged, and only the size of the shell of the electrical connector is changed. This reduces the application cost of the optical module of the disclosure.

[0027] In an implementation manner, the main plate includes a slot, the slot penetrates through two opposite surfaces of the main plate, and has an opening at an end of the main plate away from the optical interface. In the first direction, the two gold finger groups are arranged on the two sides of the slot.

[0028] In an implementation manner, the two gold finger groups are used to connect the electrical connector. The electrical connector includes two electrical interfaces, and a partition is arranged between the two electrical interfaces. The two gold finger groups are respectively inserted into the two electrical interfaces, and the slot is used to accommodate the partition.

[0029] The technical solution provided by the disclosure is that, generally, an electrical connector only has one electrical interface and is used to connect one gold finger group. However, the optical module provided by the disclosure includes two gold finger groups, and accordingly, the electrical connector needs two electrical interfaces or one electrical interface with a larger area. Compared with designing an electrical connector with a larger area, it is simpler to simply combine two electrical connectors. For example, after combining two injection molds of the existing electrical connector, a mold of the electrical connector 110 with two interfaces 111 is obtained.

[0030] Correspondingly, the slot is arranged on the main plate to avoid the partition between the two electrical interfaces.

[0031] In an implementation manner, in the second direction, the main plate is arranged between the bottom wall and the top wall of the shell and close to the bottom wall. The second direction is perpendicular to the plug-in direction and the first direction. The two optical assemblies are arranged on the side of the main plate facing the top wall. The distance between the main plate and the top wall is larger, and the optical assemblies are more easily accommodated.

[0032] In an implementation manner, in the second direction, the distance between the main plate and the bottom wall of the shell is greater than 2 mm and less than 2.5 mm. In the QSFP-DD package optical module, the distance between the main plate and the bottom wall of the shell is greater than 2 mm and less than 2.5 mm. By setting the distance between the main plate and the bottom wall of the shell of the optical module of the disclosure to be greater than 2 mm and less than 2.5 mm, the modification of the existing QSFP-DD connector can be simplified.

[0033] In an implementation, the distance between the main board and the bottom wall of the shell along the second direction is equal to 2.25±0.02mm.

[0034] In an implementation, the width of the shell is equal to the width specified by the C form factor pluggable (CFP) 2 package. The thickness of the shell is equal to the thickness specified by the CFP 2 package. The length of the shell is greater than the length specified by the CFP 2 package.

[0035] The technical solution provided by the present disclosure has the following advantages. On the one hand, by setting the width and thickness of the shell of the optical module to be equal to the width and thickness specified by the CFP 2 package, the area of the interface on the communication device for docking the optical module does not need to change or does not need to change too much. In this way, the number of optical modules that can be inserted into the communication device does not decrease. On the other hand, by setting the length of the shell to be greater than the length specified by the CFP 2 package, the internal space of the shell is increased, which facilitates the shell to accommodate two optical assemblies.

[0036] In an implementation, the circuit board assembly includes a main board, a sub-board, and a connecting board. The main board and the sub-board are arranged in a stacked manner along a second direction and are electrically connected by the connecting board. The second direction is perpendicular to the plugging direction. Two optical assemblies are arranged on a surface of the main board facing the sub-board and are arranged along a first direction. The first direction is perpendicular to the plugging direction and the second direction. One set of gold fingers is arranged on a surface of the main board, and another set of gold fingers is arranged on a surface of the sub-board.

[0037] The technical solution provided by the present disclosure has the following advantages. By arranging the two sets of gold fingers on the main board and the sub-board, the area of the circuit board assembly is sufficient to arrange the two sets of gold fingers. The shape of the set of gold fingers can be consistent with the shape of the gold fingers of the CFP 2 package.

[0038] In an implementation, the circuit board assembly includes a main board, a sub-board, and a connecting board. The main board and the sub-board are arranged in a stacked manner along a second direction and are electrically connected by the connecting board. The second direction is perpendicular to the plugging direction of the optical module. Two optical assemblies are arranged on opposite surfaces of the main board. One set of gold fingers is arranged on a surface of the main board, and another set of gold fingers is arranged on a surface of the sub-board.

[0039] The technical solution provided by the present disclosure has the following advantages. By arranging the two optical assemblies on opposite surfaces of the main board, the area of the main board can be fully utilized to arrange the optical assemblies, and the size of the optical module and the circuit board assembly along the first direction is reduced. In addition, by arranging the main board and the sub-board in a stacked manner along the second direction, although the size of the circuit board assembly along the first direction is small, the sub-board is added, so that the circuit board assembly still has sufficient area to arrange the two sets of gold fingers.

[0040] In an implementation, the circuit board assembly includes a main board. Two optical assemblies are arranged on two opposite surfaces of the main board respectively. Two gold finger groups are arranged on the two opposite surfaces of the main board respectively.

[0041] The technical solution provided by the present disclosure can fully utilize the area of the two surfaces of the main board to arrange the optical assemblies, and reduce the size of the optical module along the first direction.

[0042] In an implementation, the circuit board assembly includes two main boards stacked along a second direction. The second direction is perpendicular to the plugging direction. Two optical assemblies are fixed to the two main boards respectively. Two gold finger groups are arranged on the surfaces of the two main boards respectively.

[0043] The technical solution provided by the present disclosure can reduce the size of the optical module and the circuit board assembly along the first direction by arranging the two optical assemblies on the two main boards stacked along the second direction. In addition, since the circuit board assembly includes the two main boards, the circuit board assembly has sufficient area to arrange the two gold finger groups.

[0044] In a second aspect, the present disclosure provides a communication system. The communication system includes a center switch, a center optical module, two optical add-drop devices, two groups of access switches and two groups of remote optical modules. The center optical module is plugged into the center switch, and two optical interfaces of the center optical module are connected to common optical interfaces of the two optical add-drop devices through two optical fibers respectively. The two groups of remote optical modules are plugged into the two groups of access switches respectively, and the two groups of remote optical modules are connected to branch optical interfaces of the two optical add-drop devices through optical fibers respectively. BRIEF DESCRIPTION OF DRAWINGS

[0045] FIG. 1 is a schematic diagram of a communication system in the related art;

[0046] FIG. 2 is a schematic diagram of a communication system provided by an embodiment of the present disclosure;

[0047] FIG. 3 is an external view of an optical module provided by an embodiment of the present disclosure;

[0048] FIG. 4 is an external view of an optical module provided by an embodiment of the present disclosure from another angle;

[0049] FIG. 5 is a three-dimensional schematic diagram of an internal structure of an optical module provided by an embodiment of the present disclosure;

[0050] FIG. 6 is a schematic diagram of an internal structure of an optical module provided by an embodiment of the present disclosure;

[0051] FIG. 7 is an internal optical path diagram of an optical assembly provided by an embodiment of the present disclosure;

[0052] FIG. 8 is an equivalent optical path diagram of the internal optical path diagram shown in FIG. 7;

[0053] FIG. 9 is an internal optical path diagram of another optical assembly provided by an embodiment of the present disclosure;

[0054] FIG. 10 is an equivalent optical path diagram of the internal optical path diagram shown in FIG. 9;

[0055] FIG. 11 is a side view of an internal structure of a first optical module provided by an embodiment of the present disclosure;

[0056] FIG. 12 is a top view of the internal structure of the first optical module provided by an embodiment of the present disclosure;

[0057] FIG. 13 is a schematic diagram of a pin sequence of a gold finger of a top face of a QSFP-DD package definition provided by an embodiment of the present disclosure;

[0058] FIG. 14 is a schematic diagram of a pin sequence of a gold finger of a bottom face of a QSFP-DD package definition provided by an embodiment of the present disclosure;

[0059] FIG. 15 is a schematic diagram of a pin sequence of a gold finger of a top face of a two gold finger group provided by an embodiment of the present disclosure;

[0060] FIG. 16 is a schematic diagram of a pin sequence of a gold finger of a bottom face of a two gold finger group provided by an embodiment of the present disclosure;

[0061] FIG. 17 is a schematic diagram of a mating of an optical module and an electrical connector provided by an embodiment of the present disclosure;

[0062] FIG. 18 is a side view of an optical module provided by an embodiment of the present disclosure;

[0063] FIG. 19 is a top view of an internal structure of a second optical module provided by an embodiment of the present disclosure;

[0064] FIG. 20 is a side view of the internal structure of the second optical module provided by an embodiment of the present disclosure;

[0065] FIG. 21 is a top view of an internal structure of a third optical module provided by an embodiment of the present disclosure;

[0066] FIG. 22 is a side view of the internal structure of the third optical module provided by an embodiment of the present disclosure;

[0067] FIG. 23 is a top view of an internal structure of a fourth optical module provided by an embodiment of the present disclosure;

[0068] FIG. 24 is a side view of the internal structure of the fourth optical module provided by an embodiment of the present disclosure;

[0069] FIG. 25 is a side view of an internal structure of a fifth optical module provided by an embodiment of the present disclosure.

[0070] Legend 100, central switch, 110, electrical connector, 111, electrical interface, 112, partition, 200, central optical module, 300, multiplexer / demultiplexer, 400, access switch, 500, remote optical module; 1, shell, 101, bottom wall, 102, top wall, 11, optical interface; 2, circuit board, 21, gold finger group, 211, sub gold finger group, 2111, gold finger row, 22, slot, 201, main board, 202, sub board, 203, connecting plate; 3, optical assembly, 31, optical transmitting assembly, 311, optical transmitting assembly shell, 312, laser, 313, multiplexer / demultiplexer assembly, 3131, multiplexer assembly, 3132, sub multiplexer / demultiplexer assembly, 32, optical receiving assembly, 321, optical receiving assembly shell, 322, detector, 323, demultiplexer assembly, 33, fiber connector; 4, first optical fiber; 5, second optical fiber; X, plugging direction, Y, first direction, Z, second direction. DETAILED DESCRIPTION

[0071] Figure 1 shows a schematic diagram of a communication system in the related art. As shown in Figure 1, the communication system includes a central switch 100, a central optical module 200, an optical multiplexer / demultiplexer 300, a plurality of access switches 400 and a plurality of remote optical modules 500. The central optical module 200 is plugged into the central switch 100. The central optical module 200 includes an optical interface, which is connected to a common optical interface of the optical multiplexer / demultiplexer 300 through an optical fiber. The central optical module 200 can realize the transmission and reception of optical beams through a single optical interface and a single optical fiber. The remote optical module 500 is plugged into the access switch 400, and the remote optical module 500 is connected to a branch optical interface of the optical multiplexer / demultiplexer 300 through an optical fiber.

[0072] The central switch 100 can also be referred to as a core point (CP) switch. The access switch 400 can also be referred to as an access point (AP) switch. The central optical module 200 can also be referred to as a CP optical module or a local optical module. The remote optical module 500 can also be referred to as an AP optical module or a terminal optical module.

[0073] In the process that the center switch 100 sends signals to the plurality of access switches 400, the center switch 100 sends a plurality of transmitting electrical signals to the center optical module 200. The center optical module 200 converts the plurality of transmitting electrical signals into a plurality of light beams, and combines the plurality of light beams into a first combined light beam. The first combined light beam is sent to the common optical interface of the optical add-drop device 300 through the optical interface. The optical add-drop device 300 divides the first combined light beam into a plurality of light beams, and sends the plurality of light beams to the corresponding remote optical modules 500 through the branch optical interfaces. The remote optical modules 500 convert the received light beams into electrical signals, and send the electrical signals to the access switches 400.

[0074] In the process that the plurality of access switches 400 send signals to the center switch 100, the access switches 400 send electrical signals to the remote optical modules 500. The remote optical modules 500 convert the electrical signals into light beams, and send the light beams to the branch optical interfaces of the optical add-drop device 300. The light beams sent by the remote optical modules 500 are of different wavelength bands. The optical add-drop device 300 combines the plurality of received light beams into a second combined light beam, and sends the second combined light beam to the center optical module 200 through the common optical interface. The center optical module 200 divides the second combined light beam into a plurality of light beams, and converts the plurality of light beams into a plurality of receiving electrical signals. The plurality of receiving electrical signals are sent to the center switch 100.

[0075] For the above communication system, the more working wavelength bands covered by the first combined light beam (or the second combined light beam) transmitted by the center optical module 200, the more optical signals the first combined light beam (or the second combined light beam) can carry. Correspondingly, the more remote optical modules 500 that can be accessed by a single center optical module 200, the larger the communication capacity of the communication system.

[0076] Table 1

[0077] However, the number of working wavelength bands is limited. In order to make the first combined light beam and the second combined light beam not interfere with each other when transmitted on the same optical fiber, the working wavelength bands covered by the first combined light beam and the second combined light beam are different. Then, assuming that there are N working wavelength bands, the first combined light beam (or the second combined light beam) of a single center optical module 200 covers at most N / 2 working wavelength bands. Alternatively, it can be described that a single center optical module 200 includes at most N / 2 channels.

[0078] For example, please refer to Table 1, which shows eighteen coarse wavelength division multiplexer (CWDM) bands defined by the international telecommunication union-telecommunications standardization sector (ITU-T). Then, theoretically, the first combined light beam covers at most nine CWDM bands, and the second combined light beam covers at most another nine CWDM bands. It should be noted that in actual applications, the first combined light beam and the second combined light beam generally cover only eight CWDM bands. That is, the center optical module 200 in the related art includes at most eight channels. This limits the number of remote optical modules 500 that the communication system can access, which is not conducive to high-density access of the remote optical modules 500.

[0079] In view of the above technical problems, the embodiments of the present disclosure provide a new communication system. FIG. 2 shows a schematic diagram of a communication system provided by the embodiments of the present disclosure. As shown in FIG. 2, the communication system includes a center switch 100, a center optical module 200, two optical distribution and combination devices 300, two groups of access switches 400, and two groups of remote optical modules 500. The center optical module 200 is plugged into the center switch 100, and the center optical module 200 includes two optical interfaces, which are respectively connected to the common optical interfaces of the two optical distribution and combination devices 300. The two groups of remote optical modules 500 are plugged into the two groups of access switches 400, and the two groups of remote optical modules 500 are respectively connected to the branch optical interfaces of the two optical distribution and combination devices 300 through optical fibers. Wherein, the working process of the communication system can refer to the foregoing content, which will not be repeated here. The center optical module 200 can also be referred to as a color optical module or a color center optical module.

[0080] Since the center optical module 200 provided by the embodiments of the present disclosure includes two optical interfaces, and the optical paths of the two optical interfaces are independent of each other and will not interfere with each other. Then, assuming that a single optical interface center optical module 200 has N / 2 channels, the center optical module 200 provided by the embodiments of the present disclosure can have at most N channels. For example, N is 16, and the center optical module 200 provided by the embodiments of the present disclosure can have sixteen channels, which greatly increases the number of remote optical modules 500 that the communication system can access, so that the access density of the remote optical modules 500 is doubled.

[0081] Next, the center optical module 200 provided by the embodiments of the present disclosure will be exemplarily described. Wherein, FIG. 3 and FIG. 4 show the external shape of the optical module (i.e. the center optical module 200), and FIG. 5 and FIG. 6 show the schematic diagram of the internal structure of the optical module.

[0082] As shown in FIG. 5 and FIG. 6, the optical module includes a housing 1, a printed circuit board assembly (PCBA) 2 and two optical subassemblies 3. The housing 1 includes two optical interfaces 11, and the two optical subassemblies 3 are connected to the two optical interfaces 11 through two first optical fibers 4 respectively. Each optical subassembly 3 includes a transmitting optical subassembly (TOSA) 31 and a receiver optical subassembly (ROSA) 32. Each TOSA 31 is configured to transmit a first combined optical beam through a corresponding optical interface 11. Each ROSA 32 is configured to receive a second combined optical beam through a corresponding optical interface 11. The two optical subassemblies 3 are fixed to the PCBA 2. The PCBA 2 includes two gold finger groups 21 at an end away from the two optical interfaces 11, and the two gold finger groups 21 are electrically connected to the two optical subassemblies 3 respectively.

[0083] Compared with a conventional optical module having only one optical interface 11, one optical subassembly 3 and one gold finger group 21, the optical module provided by the embodiments of the present disclosure can double the number of channels, thereby realizing high-density access of the remote optical module 500.

[0084] In some examples, the first combined optical beam and the second combined optical beam each cover at least eight working wavelength bands. In this way, the two first combined optical beams or the two second combined optical beams can carry sixteen optical signals. That is, the optical module has sixteen optical channels. Correspondingly, each gold finger group 21 is configured to transmit at least eight transmission electrical signals to the TOSA 31 and transmit at least eight reception electrical signals generated by the ROSA 32 to a communication device. Then, the two gold finger groups 21 can transmit sixteen transmission electrical signals and sixteen reception electrical signals. That is, the optical module has sixteen electrical channels. The optical module having sixteen optical channels and sixteen electrical channels can be referred to as the optical module having sixteen channels.

[0085] In some examples, the TOSAs 31 of the two optical subassemblies 3 emit first combined optical beams covering the same working wavelength bands, and each of the working wavelength bands covers eight CWDM wavelength bands. The ROSAs 32 of the two optical subassemblies 3 receive second combined optical beams covering the same working wavelength bands, and each of the working wavelength bands covers another eight CWDM wavelength bands. Since the optical paths of the two optical subassemblies 3 are independent, the first combined optical beams transmitted by the two TOSAs 31 cover the same working wavelength bands and do not affect each other. Similarly, the second combined optical beams received by the two ROSAs 32 cover the same working wavelength bands and do not affect each other.

[0086] In some examples, the first combined light beam covers the first eight wavebands in the CWDM waveband, i.e., the wavebands of 1271 nm, 1291 nm, 1311 nm, 1331 nm, 1351 nm, 1371 nm, 1391 nm, and 1411 nm. The second combined light beam covers the ninth to sixteenth wavebands in the CWDM waveband, i.e., the wavebands of 1431 nm, 1451 nm, 1471 nm, 1491 nm, 1451 nm, 1471 nm, 1491 nm, and 1451 nm.

[0087] It can be understood that the embodiments of the present disclosure accommodate two optical assemblies 3 in the shell 1 of the optical module and arrange two gold finger groups 21 in the circuit board assembly 2. Therefore, how to reasonably arrange the optical assembly 3 and the gold finger group 21 so that the size of the shell 1 does not change or the increase in the size of the shell 1 is reduced is a key technical problem. In the following, the arrangement of the optical assembly 3 and the gold finger group 21 will be described.

[0088] First, the arrangement of each device included in the optical assembly 3 will be exemplarily described. In some examples, as shown in FIGS. 5 and 6, the optical transmitting assembly 31 and the optical receiving assembly 32 of each optical assembly 3 are arranged along the plug-in direction X of the optical module.

[0089] Among them, the plug-in direction X refers to the direction in which the optical module is inserted into the communication device and pulled out of the communication device. In addition to the plug-in direction X, the embodiments of the present disclosure also define a first direction Y and a second direction Z. The plug-in direction X, the first direction Y, and the second direction Z are perpendicular to each other. The first direction Y is parallel to the board surface of the circuit board assembly 2, and the second direction Z is perpendicular to the board surface of the circuit board assembly 2. In some examples, the plug-in direction X is the length direction of the optical module, the first direction Y is the width direction of the optical module, and the second direction Z is the thickness direction or the height direction of the optical module.

[0090] Generally, the size of the optical module along the plug-in direction X is the largest, so by arranging the optical transmitting assembly 31 and the optical receiving assembly 32 along the plug-in direction X, the space of the shell 1 of the optical module along the plug-in direction X is fully utilized to arrange the optical assembly 3. Moreover, the optical module is used to be plugged into the interface of the communication device, and the area of the interface is related to the size of the optical module along the first direction Y and the second direction Z, and is irrelevant to the size of the optical module along the plug-in direction X. Therefore, even if the length of the optical module is increased for arranging the optical assembly 3, the number of optical modules that can be connected to the communication device will not be reduced.

[0091] In some examples, as shown in FIGS. 5 and 6, the optical transmitting assembly 31 of each optical assembly 3 is closer to the gold finger group 21 than the optical receiving assembly 32.

[0092] In this way, the light emitting assembly 31 is close to the golden finger group 21, the electric conduction path between the light emitting assembly 31 and the golden finger group 21 is short, and the attenuation of the electric signal is small, which is beneficial to improve the signal quality of the first combined light beam sent by the light emitting assembly 31 and improve the reliability of the optical module.

[0093] In some examples, as shown in FIGS. 5 and 6, each optical assembly 3 further includes an optical fiber connector 33. The optical fiber connector 33 is arranged between the light emitting assembly 31 and the light receiving assembly 32 along the plug-in direction X. The optical fiber connector 33 is optically connected with the light emitting assembly 31 and the light receiving assembly 32. The optical fiber connector 33 is further connected with an optical interface 11 through a first optical fiber 4. The light emitting assembly 31 is configured to send the first combined light beam through the optical fiber connector 33, and the light receiving assembly 32 is configured to receive the second combined light beam through the optical fiber connector 33.

[0094] The technical scheme provided by the embodiments of the present disclosure arranges the optical fiber connector 33 between the light emitting assembly 31 and the light receiving assembly 32. On the one hand, the optical fiber connector 33 is close to the light emitting assembly 31 and the light receiving assembly 32, which is beneficial to the optical connection between the optical fiber connector 33 and the light emitting assembly 31 and the light receiving assembly 32. On the other hand, the optical fiber connector 33 is far away from the optical interface 11, which is beneficial to the splicing of the first optical fiber 4.

[0095] It can be understood that if the optical fiber connector 33 is arranged on the side of the light receiving assembly 32 facing the optical interface 11, the distance between the optical fiber connector 33 and the optical interface 11 is too close, which is not conducive to the splicing of the first optical fiber 4. If the optical fiber connector 33 is arranged on the side of the light emitting assembly 31 away from the light receiving assembly 32, it is not conducive to the optical connection between the optical fiber connector 33 and the light emitting assembly 31 and the light receiving assembly 32.

[0096] In some examples, the optical fiber connector 33 is a lucent connector (LC) connector.

[0097] In some examples, as shown in FIGS. 5 and 6, the optical fiber connector 33 is connected with the light emitting assembly shell 311.

[0098] Next, the internal optical path of the optical assembly 3 is exemplarily described. FIG. 7 is an internal optical path diagram of the optical assembly 3, and FIG. 8 is an equivalent optical path diagram of the internal optical path diagram shown in FIG. 7. FIG. 9 is another internal optical path diagram of the optical assembly, and FIG. 10 is an equivalent optical path diagram of the internal optical path diagram shown in FIG. 9.

[0099] In some examples, as shown in FIG. 7 and FIG. 9, the light emitting assembly 31 includes a light emitting assembly housing 311, a plurality of lasers 312, and a wavelength division multiplexing / demultiplexing assembly 313. The plurality of lasers 312 and the wavelength division multiplexing / demultiplexing assembly 313 are located inside the light emitting assembly housing 311. The wavelength division multiplexing / demultiplexing assembly 313 is optically connected with the fiber optic connector 33 and connects the light receiving assembly 32 through the second optical fiber 5. In examples, the plurality of lasers 312 is eight, and each corresponds to one of the eight CWDM wavelength bands.

[0100] As shown in FIG. 7-10, in the light transmitting direction (indicated by the solid arrow), the wavelength division multiplexing / demultiplexing assembly 313 combines the light beams transmitted by the plurality of lasers 312 into a first combined light beam, and transmits the first combined light beam through the fiber optic connector 33. In the light receiving direction (indicated by the hollow arrow), the wavelength division multiplexing / demultiplexing assembly 313 receives a second combined light beam through the fiber optic connector 33, and transmits the second combined light beam to the light receiving assembly 32 through the second optical fiber 5.

[0101] The light module provided by the embodiments of the present disclosure sets the wavelength division multiplexing / demultiplexing assembly 313 entirely inside the light emitting assembly housing 311, while in the related art, part of the wavelength division multiplexing / demultiplexing assembly 313 is arranged independently of the light emitting assembly 31 and the light receiving assembly 32. Compared with the related art, the technical solution of the embodiments of the present disclosure reduces the optical path of the light assembly 3, which is conducive to realizing the high density of the optical path of the light assembly 3 and reducing the size of the light assembly 3 in the plug-in direction X of the light module.

[0102] Next, the implementation of the wavelength division multiplexing / demultiplexing assembly 313 is exemplarily described. In some examples, as shown in FIG. 9 and FIG. 10, the wavelength division multiplexing / demultiplexing assembly 313 includes a combining assembly 3131 and a sub-wavelength division multiplexing / demultiplexing assembly 3132. In examples, the combining assembly 3131 can also be referred to as a multiplexer (MUX), and the sub-wavelength division multiplexing / demultiplexing assembly 3132 can also be referred to as a multiplexer / demultiplexer (MUX / DeMUX). In the light transmitting direction, the combining assembly 3131 combines the light beams transmitted by the plurality of lasers 312 into a first combined light beam, and transmits the first combined light beam to the sub-wavelength division multiplexing / demultiplexing assembly 3132. The sub-wavelength division multiplexing / demultiplexing assembly 3132 transmits the first combined light beam through the fiber optic connector 33. In the light receiving direction, the sub-wavelength division multiplexing / demultiplexing assembly 3132 receives a second combined light beam through the fiber optic connector 33, and transmits the second combined light beam to the light receiving assembly 32 through the second optical fiber 5.

[0103] In the related art, the sub-wavelength division multiplexing / demultiplexing assembly 3132 is arranged in a component independent of the light emitting assembly 31 and the light receiving assembly 32. By arranging the sub-wavelength division multiplexing / demultiplexing assembly 3132 inside the light emitting assembly housing 311, the embodiments of the present disclosure can reduce the size of the light assembly 3 in the plug-in direction X.

[0104] Of course, in other examples, how space is sufficient, then the sub-combining component 3132 can also be independent of the light emitting component 31 and the light receiving component 32, the embodiment of the present disclosure does not make any limitation.

[0105] In some examples, the sub-combining component 3132 can also be integrated in the combining component 3131, that is, the functions of the sub-combining component 3132 and the combining component 3131 are realized by the same device. Then, as shown in FIG. 7 and FIG. 8, the multiple light beams transmitted by the multiple lasers 312 and the second combined light beam are transmitted on the same first optical fiber 4 after one-time combining. That is, the combining of the multiple light beams into the first combined light beam also realizes the combining with the second combined light beam. The reduction of the combining level means the further shortening of the optical path, which is more conducive to reducing the size of the optical component 3 in the plug-in direction X of the optical module.

[0106] In the technical solutions shown in FIG. 9 and FIG. 10, the multiple light beams transmitted by the multiple lasers 312 are first combined once to form the first combined light beam. The first combined light beam and the second combined light beam are combined again once, and then transmitted on the same first optical fiber 4. That is, in the technical solutions shown in FIG. 9 and FIG. 10, the light is combined twice in the transmission direction. In the technical solutions shown in FIG. 7 and FIG. 8, the light is combined only once in the transmission direction.

[0107] In some examples, as shown in FIG. 7 or FIG. 9, the light receiving component 32 includes multiple detectors 322 and a demultiplexer 323. The demultiplexer 323 can also be referred to as a demultiplexer (DeMUX). The demultiplexer 323 is connected to the sub-combining component 313 of the light emitting component 3 through the second optical fiber 5. The demultiplexer 323 is used to receive the second combined light beam through the second optical fiber 5, demultiplex the second combined light beam into multiple light beams, and transmit the multiple light beams to the multiple detectors 322 respectively. In an example, the detectors 322 are eight, and correspond to eight CWDM wavebands respectively.

[0108] In some examples, as shown in FIG. 7 or FIG. 9, in order to facilitate the connection between the second optical fiber 5 and the light receiving component 32, along the plug-in direction X, the demultiplexer 323 is arranged between the multiple detectors 322 and the light emitting component 31. In this way, the second optical fiber 5 does not need to bypass the multiple detectors 322 to be connected to the demultiplexer 323, which is conducive to the routing of the second optical fiber 5. Of course, in other examples, along the plug-in direction X, the multiple detectors 322 can also be arranged between the demultiplexer 323 and the light emitting component 31, and the embodiment of the present disclosure does not make any limitation.

[0109] In some examples, as shown in FIG. 7 or FIG. 9, the light receiving component 32 further includes a light receiving component housing 321, and the multiple detectors 322 and the demultiplexer 323 are arranged inside the light receiving component housing 321.

[0110] In some examples, the light receiving assembly 32 is packaged in a form of chips on board (COB) on the circuit board assembly 2 to reduce cost. The plurality of detectors 322 and the wave division assembly 323 are in contact with the surface of the circuit board assembly 2. The light receiving assembly housing 321 is a cover that covers the plurality of detectors 322 and the wave division assembly 323.

[0111] Next, the possible arrangement of the two light assemblies 3 and the two gold finger groups 21 on the circuit board assembly 2 is exemplarily described.

[0112] (1) FIG. 11 shows a side view of the internal structure of the first optical module, and FIG. 12 shows a top view of the internal structure of the first optical module. In some examples, as shown in FIG. 11 and FIG. 12, the circuit board assembly 2 includes a main board 201. The two light assemblies 3 are arranged on the same surface of the main board 201 and arranged along the first direction Y. The two gold finger groups 21 are arranged on the surface of the main board 201 and arranged along the first direction Y. The main board 201 is a PCB board.

[0113] The technical solution provided by the embodiments of the present disclosure can avoid the size of the optical module 3 along the plugging direction X being too long by arranging the two light assemblies 3 along the first direction Y. Moreover, in general, the size of the optical module along the first direction Y is greater than the size along the second direction Z, so arranging the two light assemblies 3 along the first direction Y is conducive to fully utilizing the space of the housing 1 of the optical module along the first direction Y. Moreover, by arranging the two gold finger groups 21 along the first direction Y, the electrical connection of the two gold finger groups 21 and the two light assemblies 3 is facilitated.

[0114] Since the two light assemblies 3 are arranged along the first direction Y and distributed on the same surface of the main board 201, the width required by the housing 1 of the optical module is relatively large. Therefore, the housing 1 of the optical module is suitable for being packaged in a C form factor pluggable (CFP) 2 or a CFP 8. Alternatively, the housing 1 of the optical module is packaged in an approximate CFP 2 or an approximate CFP 8. The approximate CFP 2 or the approximate CFP 8 means that the width of the housing 1 is less than or equal to the width specified by the CFP 2 / CFP 8, the thickness of the housing 1 is less than or equal to the thickness specified by the CFP 2 / CFP 8, and the length of the housing 1 is greater than or equal to the length specified by the CFP 2 / CFP 8.

[0115] In this way, on the one hand, by setting the width and thickness of the shell 1 to be less than or equal to the width and thickness specified by the CFP2 or CFP8 package, the area and shape of the interface on the communication device for docking the optical module do not need to be changed or are changed to be smaller. In this way, the number of optical modules that can be inserted by the communication device will not be reduced. On the other hand, by setting the length of the shell 1 to be greater than the length specified by the CFP2 or CFP8 package, the internal space of the shell 1 in the length direction is increased, which facilitates the shell 1 to accommodate the optical assembly 3, and is conducive to the implementation of the optical module provided by the embodiments of the present disclosure.

[0116] In some examples, as shown in FIGS. 11 and 12, each gold finger group 21 includes two sub-gold finger groups 211, and the two sub-gold finger groups 211 are arranged on opposite sides of the main plate 201, respectively. Each sub-gold finger group 211 includes two gold finger rows 2111 arranged in the insertion and extraction direction X. Among them, by setting each sub-gold finger group 211 to include two gold finger rows 2111 arranged in the insertion and extraction direction X, the area of the main plate 201 in the insertion and extraction direction X is fully utilized to arrange gold fingers, so that two gold finger groups 21 can be arranged on one main plate 201, and each gold finger group 21 has eight electrical channels.

[0117] In some examples, the form of the gold finger group 21 is consistent with the form of the gold fingers of the quad small form factor pluggable-double density (QSFP-DD) package. Among them, the form consistent means that the shape and arrangement of the gold fingers of the gold finger group 21 are consistent with the shape and arrangement of the gold fingers of the QSFP-DD package. The pin sequence of the gold finger group 21 can be different from or the same as the pin sequence of the gold fingers of the QSFP-DD package.

[0118] The technical solutions provided by the embodiments of the present disclosure make the gold finger group 21 consistent in form with the gold fingers of the QSFP-DD package, so that the gold finger group 21 can be docked with some existing electrical connectors of the QSFP-DD package, or only needs to make some minor improvements to the electrical connectors of the QSFP-DD package, for example, the pin device in the electrical connector of the QSFP-DD package is unchanged, and only the size of the shell of the electrical connector is changed. This reduces the application cost of the optical module.

[0119] FIG. 13 shows a pin order diagram of the gold fingers on the top side of the QSFP-DD package definition, and FIG. 14 shows a pin order diagram of the gold fingers on the bottom side of the QSFP-DD package definition. The top side and the bottom side are two opposite sides of the circuit board. FIG. 13 and FIG. 14 show the pin order required by the QSFP-DD package. In some examples, the pin order of each gold finger group 21 is consistent with the pin order required by the QSFP-DD package shown in FIG. 13 and FIG. 14.

[0120] In other examples, in order to facilitate internal wiring of the main board 201 and reduce the degree of signal wiring crossing, the pin order of each gold finger group 21 can also be different from the pin order required by the QSFP-DD package. For example, compared with the pin order required by the QSFP-DD package, the order of the transmit (TX) signal pins and the receive (RX) signal pins of the gold finger group 21 in the embodiments of the present disclosure is adjusted.

[0121] FIG. 15 shows a pin order diagram of the gold fingers on the top side of two gold finger groups 21. FIG. 16 shows a pin order diagram of the gold fingers on the bottom side of two gold finger groups 21. The top side and the bottom side are two opposite sides of the main board 201.

[0122] In some examples, referring to the part enclosed by the dashed line in FIG. 15 and FIG. 16, compared with the pin order required by the QSFP-DD package, for one of the two gold finger groups 21, the positions of TX7 and TX8 are exchanged. For the other gold finger group 21, the positions of all TX pins and RX pins are exchanged. And from pin 2-1 to pin 2-76, the arrangement order of the TX pins and the RX pins is RX3, RX1, TX2, TX3, TX4, TX1, RX2, RX4, RX7, RX5, TX6, TX8, TX7, TX5, RX6, RX8.

[0123] It should be noted that the order of other pins of the gold finger group 21 can also be changed, and the specific changes can be derived by comparing FIG. 13-FIG. 14 and FIG. 15-FIG. 16.

[0124] In addition to the technical solution that the form of the gold finger group 21 is consistent with the form of the gold finger of the QSFP-DD package, in other examples, the form of the two gold finger rows 2111 opposite and on different surfaces of the main board 201 is consistent with the form of the gold finger of the CFP4 package. Then each gold finger group 21 includes two CFP4 package form gold fingers, and the two CFP4 package form gold fingers are arranged along the plug-in direction X. Each CFP4 package form gold finger includes four electrical channels. In some examples, the pin sequence of the two gold finger rows 2111 opposite and on different surfaces of the main board 201 is the same as the pin sequence of the gold finger of the CFP4 package.

[0125] FIG. 17 shows a schematic diagram of the optical module and the electrical connector 110. As shown in FIG. 17, the main board 201 includes a slot 22, the slot 22 penetrates through the two opposite surfaces of the main board 201, and has an opening at the end of the main board 201 away from the optical interface 11. Along the first direction Y, the two gold finger groups 21 are arranged on the two sides of the slot 22. The two gold finger groups 21 are used to dock the electrical connector 110, the electrical connector 110 includes two electrical interfaces 111, and the two electrical interfaces 111 are provided with a partition 112. The two gold finger groups 21 are respectively inserted into the two electrical interfaces 111, and the slot 22 is used to accommodate the partition 112.

[0126] The technical solution provided by the embodiments of the present disclosure is generally that an electrical connector 110 has only one electrical interface 111 and is used to dock one gold finger group. However, the optical module provided by the embodiments of the present disclosure includes two gold finger groups 21, and accordingly, the electrical connector 110 needs to have two electrical interfaces 111, or have one electrical interface 111 with a larger size. Compared with designing an electrical connector 110 with a larger area electrical interface 111, it is simpler to combine two electrical connectors 110. For example, after combining two injection molds of the electrical connector 110, a mold of the electrical connector 110 with two electrical interfaces 111 is obtained. Accordingly, the slot 22 is arranged on the main board 201 to avoid the partition 112 between the two electrical interfaces 111.

[0127] Of course, in other examples, the slot 22 can not be arranged on the main board 201, and the two gold finger groups 21 are used to be inserted into one electrical interface 111.

[0128] FIG. 18 shows a side view of the optical module. In some examples, as shown in FIG. 18, along the second direction Z, the main board 201 is arranged between the bottom wall 101 and the top wall 102 of the housing 1 and close to the bottom wall 101. In this way, the distance between the main board 201 and the top wall 102 is larger, and the two optical assemblies 3 are arranged on the surface of the main board 201 facing the top wall 102.

[0129] In some examples, as shown in FIG. 18, the spacing d1 between the main board 201 and the bottom wall 101 of the shell 1 along the second direction Z is greater than 2 mm and less than 2.5 mm. In the optical module of the QSFP-DD package, the spacing between the main board 201 and the bottom wall 101 of the shell 1 is greater than 2 mm and less than 2.5 mm. For example, the spacing d1 is 2.25 ± 0.1 mm.

[0130] The technical solution provided by the embodiments of the present disclosure sets the spacing d1 to be greater than 2 mm and less than 2.5 mm, so that the spacing between the main board 201 and the bottom wall 101 of the shell 1 can still adapt to the QSFP-DD connector. In this way, the modification of the electrical connector 110 compared to the single QSFP-DD connector can be reduced.

[0131] (2) FIG. 19 shows a top view of the internal structure of a second optical module, and FIG. 20 is a side view showing the internal structure of the second optical module. In some examples, as shown in FIGS. 19 and 20, the circuit board assembly 2 includes a main board 201, a sub-board 202, and a connecting board 203. The main board 201 and the sub-board 202 are arranged in a stacked manner along the second direction Z. The main board 201 and the sub-board 202 are electrically connected by the connecting board 203. Two optical assemblies 3 are arranged on the side of the main board 201 facing the sub-board 202, and are arranged along the first direction Y of the optical module. One gold finger group 21 is arranged on the surface of the main board 201, and the other gold finger group 21 is arranged on the surface of the sub-board 202. For example, the main board 201 and the sub-board 202 are PCB boards, and the connecting board 203 is a flexible board, which electrically connects one side of the main board 201 and one side of the sub-board 202.

[0132] The technical solution provided by the embodiments of the present disclosure sets the circuit board assembly 2 to include the main board 201 and the sub-board 202 arranged in a stacked manner, so that the circuit board assembly 2 has sufficient area to arrange two gold finger groups 21. Moreover, the form of the gold finger group 21 can not only be consistent with the form of the gold finger of the QSFP-DD package, but also be consistent with the form of the gold finger of the CFP2 package. The gold finger of the CFP2 package includes ten electrical channels.

[0133] In some examples, the pin sequence of the gold finger group 21 is the same as the pin sequence of the gold finger of the CFP2 package.

[0134] In addition, the package of the housing 1 can adopt a CFP2 package or a CFP8 package. Alternatively, a package similar to the CFP2 or the CFP8. Wherein, the package similar to the CFP2 or the CFP8 refers to that the width of the housing 1 is less than or equal to the width specified by the CFP2 package or the CFP8 package, the thickness of the housing 1 is less than or equal to the thickness specified by the CFP2 package or the CFP8 package, and the length of the housing 1 is greater than or equal to the length specified by the CFP2 package or the CFP8 package.

[0135] (3) FIG. 21 shows a top view of the internal structure of the third optical module, and FIG. 22 shows a side view of the internal structure of the third optical module. In some examples, as shown in FIG. 21 and FIG. 22, the circuit board assembly 2 includes a main board 201, a sub-board 202, and a connecting board 203. The main board 201 and the sub-board 202 are arranged in a stacked manner along the second direction Z. The main board 201 and the sub-board 202 are electrically connected through the connecting board 203. Two optical assemblies 3 are arranged on the opposite surfaces of the main board 201, respectively. One set of gold fingers 21 is arranged on the surface of the main board 201, and the other set of gold fingers 21 is arranged on the surface of the sub-board 202.

[0136] The technical solution provided by the embodiments of the present disclosure can fully utilize the area of the two surfaces of the main board 201 to arrange the optical assemblies 3, thereby reducing the size of the optical module and the circuit board assembly 2 along the first direction. In addition, by arranging the circuit board assembly 2 to include the main board 201 and the sub-board 202, although the size of the circuit board assembly 2 along the first direction Y is small, the sub-board 202 is added, so that the circuit board assembly 2 still has sufficient area to arrange the two sets of gold fingers 21.

[0137] Since the optical module has a smaller volume, the package of the housing 1 of the optical module can adopt a CFP2 package, a 12x small form-factor pluggable (CXP) package, an open small form-factor pluggable (OSFP) package, or a QSFP-DD package. Alternatively, the housing 1 of the optical module adopts a package similar to the CFP2, the CXP, the OSFP, or the QSFP-DD.

[0138] Wherein, the package similar to the CFP2, the CXP, the OSFP, or the QSFP-DD refers to that the width of the housing 1 is less than or equal to the width specified by the corresponding package standard, the thickness of the housing 1 is less than or equal to the thickness specified by the corresponding package standard, and the length of the housing 1 is greater than or equal to the length specified by the corresponding package standard.

[0139] In some examples, the form of each gold finger group 21 of the optical module is consistent with the form of the gold fingers of a CFP2 package, a CXP package, an OSFP package, or a QSFP-DD package. Further, in some examples, the pin sequence of each gold finger group 21 is consistent with the pin sequence of the gold fingers of a CFP2 package, a CXP package, an OSFP package, or a QSFP-DD package.

[0140] (4) FIG. 23 shows a top view of the internal structure of a fourth optical module, and FIG. 24 shows a side view of the internal structure of the fourth optical module. In some examples, as shown in FIG. 23 and FIG. 24, the circuit board assembly 2 includes a main board 201, and two optical assemblies 3 are arranged on opposite sides of the main board 201, respectively. Two gold finger groups 21 are arranged on the surfaces of the main board 201, respectively.

[0141] The technical solutions provided by the embodiments of the present disclosure can fully utilize the areas of the two surfaces of the main board 201 to arrange the optical assemblies 3 and the gold finger groups 21, and reduce the size of the optical module along the first direction Y.

[0142] In some examples, the package adopted by the housing 1 of the optical module can be an OSFP-XD (open small form-factor pluggable-xtreme density) package, or an approximate OSFP-XD package. The approximate OSFP-XD package means that the width of the housing 1 is less than or equal to the width specified by the OSFP-XD package, the thickness of the housing 1 is less than or equal to the thickness specified by the OSFP-XD package, and the length of the housing 1 is greater than or equal to the length specified by the OSFP-XD package.

[0143] In some examples, the form of the gold finger group 21 of the optical module is consistent with the form of the gold fingers of the OSFP-XD package. The pin sequence of the gold finger group 21 is the same as or different from the pin sequence of the gold fingers of the OSFP-XD package.

[0144] (5) FIG. 25 shows a side view of the internal structure of a fifth optical module. In some examples, as shown in FIG. 25, the circuit board assembly 2 includes two main boards 201. The two main boards 201 are arranged in a stack along the second direction Z. Two optical assemblies 3 are fixed to the two main boards 201, respectively. Two gold finger groups 21 are arranged on the surfaces of the two main boards 201, respectively.

[0145] The technical scheme provided by the embodiments of the present disclosure reduces the size of the optical module and the circuit board assembly 2 along the first direction Y by arranging two main boards 201 along the second direction Z and arranging two optical assemblies 3 on the two main boards 201. In addition, since the circuit board assembly 2 includes two main boards 201, the circuit board assembly 2 has sufficient area to arrange two gold finger groups 21.

[0146] In some examples, the housing 1 of the optical module adopts a CFP2 package, a CXP package, an OSFP package, or a QSFP-DD package. Alternatively, a package similar to CFP2, CXP, OSFP, or QSFP-DD is adopted.

[0147] In some examples, the form of the gold finger group 21 is consistent with the form of the gold finger of the CFP2 package, the CXP package, the OSFP package, or the QSFP-DD package. In some examples, the pin sequence of the gold finger group 21 is consistent with the pin sequence of the gold finger of the CFP2 package, the CXP package, the OSFP package, or the QSFP-DD package.

[0148] (6) In some examples, the housing 1 of the optical module and the gold finger adopt a CFP8 package, a 400 form-factor pluggable (CDFP) package, or a 12x small form-factor pluggable-double density (CXP-DD) package. Since the gold finger in the CFP8 package, the CDFP package, and the CXP-DD package originally has 16 channels, only two optical assemblies 3 need to be placed in the housing 1 of such an optical module. The two optical assemblies 3 can be placed on both sides of the main board 201, or can be placed side by side along the first direction Y on the same side of the main board 201.

[0149] The above description is only optional embodiments of the present disclosure and is not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. An optical module characterized by comprising: The optical module comprises a housing (1), a circuit board assembly (2) and two optical assemblies (3); The housing (1) comprises two optical interfaces (11), the two optical assemblies (3) are connected to the two optical interfaces (11) through two first optical fibers (4) respectively, the optical assembly (3) comprises optical transmitting assemblies (31) and optical receiving assemblies (32) arranged along the plug-in direction (X) of the optical module, each optical transmitting assembly (31) is used for transmitting a first combined light beam through one optical interface (11), and each optical receiving assembly (32) is used for receiving a second combined light beam through one optical interface (11); The two optical assemblies (3) are fixed to the circuit board assembly (2), and the circuit board assembly (2) comprises two gold finger groups (21) at the end away from the two optical interfaces (11), and the two gold finger groups (21) are electrically connected to the two optical assemblies (3) respectively.

2. The optical module according to claim 1, characterized by The first combined light beam and the second combined light beam cover at least eight working wave bands; Each gold finger group (21) is used for transmitting at least eight transmitting electrical signals to the optical transmitting assembly (31), and transmitting at least eight receiving electrical signals generated by the optical receiving assembly (32) to a communication device.

3. The optical module according to claim 2, characterized by The first combined light beams emitted by the optical transmitting assemblies (31) of the two optical assemblies (3) cover the same working wave bands, and cover eight coarse wave division multiplexers (CWDM) wave bands; The second combined light beams received by the optical receiving assemblies (32) of the two optical assemblies (3) cover the same working wave bands, and cover another eight CWDM wave bands.

4. The optical module according to any one of claims 1 to 3, characterized by, The optical transmitting assembly (31) of each optical assembly (3) is closer to the gold finger group (21) than the optical receiving assembly (32).

5. The optical module according to claim 4, characterized by The optical assembly (3) further comprises an optical fiber connector (33), which is arranged between the optical transmitting assembly (31) and the optical receiving assembly (32) along the plug-in direction (X), and the optical fiber connector (33) is optically connected to the optical transmitting assembly (31) and the optical receiving assembly (32); The optical fiber connector (33) is connected to one optical interface (11) through one first optical fiber (4); The optical transmitting assembly (31) is used for transmitting the first combined light beam through the optical fiber connector (33), and the optical receiving assembly (32) is used for receiving the second combined light beam through the optical fiber connector (33).

6. The optical module according to claim 5, characterized by The optical transmitting assembly (31) comprises an optical transmitting assembly shell (311), a plurality of lasers (312) and a splitting and combining assembly (313); The plurality of lasers (312) and the splitting and combining assembly (313) are located inside the optical transmitting assembly shell (311), the splitting and combining assembly (313) is optically connected to the optical fiber connector (33) and connected to the optical receiving assembly (32) through a second optical fiber (5); In the light transmitting direction, the wavelength division and combination assembly (313) is configured to combine the light beams transmitted by the plurality of lasers (312) into the first combined light beam, and transmit the first combined light beam through the optical fiber connector (33); In the light receiving direction, the wavelength division and combination assembly (313) is configured to receive the second combined light beam through the optical fiber connector (33), and transmit the second combined light beam to the light receiving assembly (32) through the second optical fiber (5).

7. The optical module according to claim 6, characterized by The plurality of light beams transmitted by the plurality of lasers (312) and the second combined light beam are transmitted on the same first optical fiber (4) after one wavelength division and combination.

8. The optical module of claim 6, wherein, The wavelength division and combination assembly (313) comprises a combination assembly (3131) and a sub wavelength division and combination assembly (3132). In the light transmitting direction, the combination assembly (3131) is configured to combine the light beams transmitted by the plurality of lasers (312) into the first combined light beam, and transmit the first combined light beam to the sub wavelength division and combination assembly (3132), and the sub wavelength division and combination assembly (3132) is configured to transmit the first combined light beam through the optical fiber connector (33); In the light receiving direction, the sub wavelength division and combination assembly (3132) is configured to receive the second combined light beam through the optical fiber connector (33), and transmit the second combined light beam to the light receiving assembly (32) through the second optical fiber (5).

9. The optical module according to any one of claims 6 to 8, characterized by, The light receiving assembly (32) comprises a plurality of detectors (322) and a wavelength division assembly (323), and the wavelength division assembly (323) is arranged between the plurality of detectors (322) and the light transmitting assembly (31) along the plug-in direction (X); The wavelength division assembly (323) is connected to the wavelength division and combination assembly (313) of the light transmitting assembly (31) through the second optical fiber (5); The wavelength division assembly (323) is configured to receive the second combined light beam through the second optical fiber (5), divide the second combined light beam into a plurality of light beams, and transmit the plurality of light beams to the plurality of detectors (322) respectively.

10. The optical module according to any one of claims 1 to 9, characterized by, The circuit board assembly (2) comprises a main body board (201), and the two light assemblies (3) are arranged on the same surface of the main body board (201) and arranged along a first direction (Y), wherein the first direction (Y) is perpendicular to the plug-in direction (X) and parallel to the main body board (201); The two gold finger groups (21) are arranged on the surface of the main body board (201) and arranged along the first direction (Y).

11. The optical module according to claim 10, characterized by Each of the gold finger groups (21) comprises two sub gold finger groups (211) arranged on opposite surfaces of the main body board (201) respectively. Each of the sub gold finger groups (211) comprises two gold finger rows (2111) arranged along the plug-in direction (X).

12. The optical module of claim 11, wherein, The shape of the gold finger group (21) is consistent with the shape of the gold finger of the double-density four-channel small form-factor pluggable QSFP-DD package.

13. The optical module according to any one of claims 10 to 12, characterized by, The main plate (201) comprises a slot (22) penetrating through two opposite surfaces of the main plate (201), and the slot (22) has an opening at an end of the main plate (201) away from the optical interface (11); Along the first direction (Y), the two gold finger groups (21) are arranged on both sides of the slot (22).

14. The optical module according to claim 13, characterized by The two gold finger groups (21) are used for plugging into the electrical connector (110), wherein the electrical connector (110) comprises two interfaces (111), and a partition rib (112) is arranged between the two interfaces (111); The two gold finger groups (21) are respectively inserted into the two interfaces (111), and the slot (22) is used for accommodating the partition rib (112).

15. The optical module according to any one of claims 10 to 14, characterized by, Along the second direction (Z), the main plate (201) is arranged between the bottom wall (101) and the top wall (102) of the shell (1) and close to the bottom wall (101), wherein the second direction (Z) is perpendicular to the plug-in direction (X) and the first direction (Y); The two optical assemblies (3) are arranged on a surface of the main plate (201) facing the top wall (102).

16. The optical module of claim 15, wherein, Along the second direction (Z), the distance between the main plate (201) and the bottom wall (101) of the shell (1) is greater than 2mm and less than 2.5mm.

17. The optical module according to any one of claims 10 to 16, characterized by, The width of the shell (1) is equal to the width specified in the CFP2 package, the thickness of the shell (1) is equal to the thickness specified in the CFP2 package, and the length of the shell (1) is greater than the length specified in the CFP2 package.

18. The optical module according to any one of claims 1 to 9, characterized by, The circuit board assembly (2) comprises a main plate (201), a sub-plate (202) and a connecting plate (203), the main plate (201) and the sub-plate (202) are arranged in a stack along the second direction (Z) and are electrically connected through the connecting plate (203), wherein the second direction (Z) is perpendicular to the plug-in direction (X); The two optical assemblies (3) are arranged on a surface of the main plate (201) facing the sub-plate (202) and along the first direction (Y), wherein the first direction (Y) is perpendicular to the plug-in direction (X) and the second direction (Z); One of the gold finger groups (21) is arranged on a surface of the main plate (201), and the other gold finger group (21) is arranged on a surface of the sub-plate (202).

19. The optical module according to any one of claims 1 to 9, characterized by, The circuit board assembly (2) comprises a main plate (201), a sub-plate (202) and a connecting plate (203), the main plate (201) and the sub-plate (202) are arranged in a stack along the second direction (Z) and are electrically connected through the connecting plate (203), wherein the second direction (Z) is perpendicular to the plug-in direction (X) of the optical module; The two optical assemblies (3) are respectively arranged on two opposite surfaces of the main plate (201); One of the gold finger groups (21) is arranged on a surface of the main plate (201), and the other gold finger group (21) is arranged on a surface of the sub-plate (202).

20. The optical module according to any one of claims 1 to 9, characterized by, The circuit board assembly (2) comprises a main board (201), and the two optical assemblies (3) are arranged on two opposite surfaces of the main board (201) respectively. The two gold finger groups (21) are arranged on two opposite surfaces of the main board (201) respectively.

21. The optical module according to any one of claims 1 to 9, characterized by, The circuit board assembly (2) comprises two main boards (201), and the two main boards (201) are arranged in a stacking mode along a second direction (Z), wherein the second direction (Z) is perpendicular to the plugging direction (X). The two optical assemblies (3) are fixed to the two main boards (201) respectively. The two gold finger groups (21) are arranged on surfaces of the two main boards (201) respectively.

22. A communication system, characterized by The communication system comprises a center switch (100), a center optical module (200), two optical distribution devices (300), two groups of access switches (400) and two groups of remote optical modules (500), the center optical module (200) is the optical module as claimed in any one of claims 1-21; The center optical module (200) is plugged into the center switch (100), and two optical interfaces (11) of the center optical module (200) are connected to common optical interfaces of the two optical distribution devices (300) through two optical fibers respectively. The two groups of remote optical modules (500) are plugged into the two groups of access switches (400) respectively, and the two groups of remote optical modules (500) are connected to branch optical interfaces of the two optical distribution devices (300) through optical fibers respectively.

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