Patent ID: 12235497

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, technical solutions in some embodiments of the present disclosure will be described clearly and completely with reference to the accompanying drawings. Obviously, the described embodiments merely show some but not all embodiments of the present disclosure. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present disclosure shall fall within the protection scope of the present disclosure.

In the description of the specification, the terms “one embodiment”, “some embodiments”, “exemplary embodiment(s)”, “an example”, “a specific example” or “some examples” etc. are intended to indicate that specific features, structures, materials or properties related to the embodiment(s) or example(s) are comprised in at least one embodiment or example of the present disclosure. Schematic representations of the above terms do not necessarily refer to the same embodiment(s) or example(s). In addition, the specific features, structures, materials or characteristics described may be comprised in any one or more embodiments or examples in any suitable manner.

Hereinafter, the terms “first” and “second” are used for descriptive purposes only, and are not to be construed as indicating or implying the relative importance or implicitly indicating the number of indicated technical features. Thus, features defined with “first” and “second” may explicitly or implicitly comprise one or more of the features. In the description of the embodiments of the present disclosure, “plurality” means two or more unless otherwise specified.

In describing some embodiments, the expression “connected” and its derivatives may be used. For example, the term “connected” may be used in the description of some embodiments to indicate that two or more parts are in direct physical or electrical contact with each other. However, the term “connected” may also mean that two or more parts are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited by the contents herein.

The use of the term “configured to” herein is meant to be open and inclusive, and is not meant to exclude a situation that the device is configured to perform additional tasks or steps.

Additionally, the use of the term “based on” is meant to be open and inclusive, as a process, step, calculation or other actions “based on” one or more of the stated conditions or values may in practice be based on additional conditions or values.

FIG.1is a schematic diagram of a connection relationship of optical communication terminals. As shown inFIG.1, the connection of the optical communication terminals mainly comprises interconnections between an optical network terminal100, an optical module200, an optical fiber101and a network cable103.

One end of the optical fiber101is connected to a remote server, and one end of the network cable103is connected to a local information processing device. The connection between the local information processing device and the remote server is realized by the connection between the optical fiber101and the network cable103; while the connection between the optical fiber101and the network cable103is achieved by the optical network terminal100with the optical module200.

The optical fiber101is connected to an optical port of the optical module200, and a two-way optical-signal-connection is established between the optical module200and the optical fiber101; an electrical port of the optical module200is connected to the optical network terminal100, and a two-way electrical-signal-connection is established between the optical module200and the optical network terminal100; a mutual conversion between optical signals and electrical signals takes place internally within the optical module, so as to establish an information connection between the optical fiber and the optical network terminal. In some embodiments of the present disclosure, an optical signal from an optical fiber is converted into an electrical signal by the optical module and then input into the optical network terminal100, and an electrical signal from the optical network terminal100is converted into an optical signal by the optical module and input into the optical fiber.

The optical network terminal has an optical module interface102for receiving the optical module200and establishing a two-way electrical-signal-connection with the optical module200; the optical network terminal has a network cable interface for receiving the network cable103and establishing a two-way electrical-signal-connection with the network cable103; the connection between the optical module200and the network cable103is established via the optical network terminal100. In some embodiments of the present disclosure, the optical network terminal transmits signals from the optical module to the network cable, and transmits signals from the network cable to the optical module, and the optical network terminal serves as the host computer of the optical module to monitor the operation of the optical module.

So far, the remote server has established a two-way signal transmission channel with the local information processing device through the optical fiber, the optical module, the optical network terminal and the network cable.

A common information processing device comprises routers, switches, electronic computers, etc.; the optical network terminal is the host computer of the optical module, providing data signals to the optical module and receiving data signals from the optical module. A common optical module host computer may also be an optical line terminal, etc.

FIG.2is a schematic structural diagram of an optical network terminal. As shown inFIG.2, the optical network terminal100includes a circuit board105, and a cage106is provided on the surface of the circuit board105; an electrical connector is provided inside the cage106for connecting to an optical module electrical port such as a golden finger; a heat sink107is provided on the cage106, and the heat sink107has a first protrusion such as fins for increasing heat dissipation area.

The optical module200is inserted into the optical network terminal100, specifically, the electrical port of the optical module is inserted into the electrical connector inside the cage106, and the optical port of the optical module is connected with the optical fiber101.

The cage106is located on the circuit board, and the electrical connectors on the circuit board are wrapped in the cage; the optical module200is inserted into the cage and is fixed by the cage, and the heat generated by the optical module200is conducted to the cage106and then diffuses through the heat sink107on the cage.

FIG.3is a schematic structural diagram of an optical module according to an embodiment of the present disclosure, andFIG.4is a schematic exploded diagram of an optical module according to an embodiment of the present disclosure. As shown inFIG.3andFIG.4, the optical module200according to the embodiment of the present disclosure comprises an upper casing201, a lower casing202, an unlocking part203, a circuit board300and an optical sub-module400.

The upper casing201is covered on the lower casing202to form a wrapping cavity with two openings; the outer contour of the wrapping cavity generally presents a square shape. In some embodiments of the present disclosure, the lower casing202comprises a main board and two side plates located on both sides of the main board and are perpendicular to the main board; the upper casing comprises a cover plate, and the cover plate covers the two side plates of the upper casing to form a wrapping cavity; the upper casing may also comprise two side walls located on both sides of the cover plate and are perpendicular to the cover plate, and the two side walls cooperates with the two side plates to realize the covering of the upper casing201on the lower casing202.

One of the two openings is an electrical port204from which the golden fingers of the circuit board protrude and are inserted into a host computer such as an optical network terminal; the other opening is an optical port205, which is used to receive external optical fibers to connect the optical sub-module400inside the optical module; the optoelectronic devices such as the circuit board300and the optical sub-module400are located in the wrapping cavity.

The assembly method of combining the upper casing and the lower casing is convenient to install the circuit board300, the optical sub-module400and other devices into the casing, and the upper casing and the lower casing form the outermost packaging protection casing of the module; the upper casing and the lower casing are generally made of metal materials, which are intend to achieve electromagnetic shielding and heat dissipation, so generally, the casing of the optical module are not made into an integral part so that when assembling circuit boards and other devices, positioning parts, heat dissipation and electromagnetic shielding components can not to be installed, and this is not conducive to production automation.

The unlocking part203is located on the outer wall of the wrapping cavity/lower casing202, and is used to realize the fixed connection between the optical module and the host computer, or to release the fixed connection between the optical module and the host computer.

The unlocking part203has a snap part matched with the cage of the host computer; the unlocking part203can be moved relatively on the surface of the outer wall by pulling the end of the unlocking part203; the optical module200is inserted into the cage of the host computer and is fixed in the cage of the host computer by the snap part of the unlocking part203; by pulling the unlocking part203, the snap part of the unlocking part203moves with it, thereby changes the connection relationship between the snap part and the host computer to release the snapping relationship between the optical module and the host computer, so that the optical module can be pulled out from the cage of the host computer.

Circuit wirings, electronic components (such as capacitors, resistors, triodes, MOS tubes) and chips (such as MCU, laser driver chip, amplitude limiting amplifier chip, clock data recovery CDR, power management chip, data processing chip DSP), etc. are provided on the circuit board300.

The circuit board300is used to provide a signal circuit for electrical connection of the signal, and the signal circuit can provide the signal. The circuit board300connects the electrical devices in the optical module together through circuit wirings according to the circuit design, so as to realize electrical functions such as power supply, electrical signal transmission, and grounding.

The circuit board is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also realize the bearing function. For example, the rigid circuit board can bear the chip securely; when the optical transceiver components are located on the circuit board, the rigid circuit board can also provide stable bearing; the rigid circuit board can also be inserted into the electrical connector in the cage of the host computer. In some embodiments of the present disclosure, metal pins/golden fingers are formed on one end surface of the rigid circuit board for connecting with the electrical connector; all these are inconvenient to implement with flexible circuit boards.

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

The light-emitting sub-module and the light-receiving sub-module may be collectively referred to as an optical sub-module. As shown inFIG.4, the optical module according to an embodiment of the present disclosure comprises a light-emitting sub-module and a light-receiving sub-module, the light-emitting sub-module and the light-receiving sub-module are integrated into one optical sub-module, which means, there is integrated a light-emitting assembly and a light-receiving assembly inside the optical sub-module400. In some embodiments of the present disclosure, the light-emitting assembly is closer to the lower casing202than the light-receiving assembly, but not limited thereto, the light-receiving assembly may also be closer to the lower casing202than the light-emitting assembly.

In some embodiments of the present disclosure, the circuit board300can be directly inserted into the optical sub-module400to be directly electrically connected with the light-emitting assembly and the light-receiving assembly inside the optical sub-module400; the optical sub-module400can also be physical separated from the circuit board300and connected to the circuit board through flexible circuit boards.

When the light-emitting assembly is closer to the lower case202than the light-receiving assembly, both the light-emitting assembly and the light-receiving assembly are integrated in the inner cavity of the optical sub-module400, and the light-emitting assembly and the light-receiving assembly are separated by a separation board, and the optical sub-module400is disposed in the wrapping cavity formed by the upper casing201and the lower casing202.

FIG.5is a schematic assembly diagram of an optical sub-module400and a circuit board300in an optical module according to an embodiment of the present disclosure, andFIG.6is an exploded schematic view of the optical sub-module400and the circuit board300in an optical module according to an embodiment of the present disclosure. As shown inFIG.5andFIG.6, the optical sub-module400comprises a housing assembly410, the upper surface of which is formed with a light-receiving portion in which an optical component and a light-receiving assembly is located. As an example, the light-receiving portion includes a light-receiving cavity and a slot that are downwardly recessed respectively. A partition wall is provided between the light-receiving cavity and the slot, which partition wall comprises light-passing holes to communicate the light-receiving cavity with the slot; the lower surface of the housing assembly comprises an upwardly recessed light-emitting cavity; a separation board is formed in the middle of the housing assembly.

The light-emitting assembly is located in the light-emitting cavity; the optical component is located in the light-receiving cavity, and the light-receiving assembly is located in the slot. Both the light-emitting assembly and the light-receiving assembly are disposed in the inner cavity of the housing assembly410, the light-receiving assembly and the light-emitting assembly are stacked one above the other, and the light-receiving assembly and the light-emitting assembly are separated by a separation board in the housing assembly410, the light-receiving assembly is disposed above the separation board, and the light-emitting assembly is disposed below the separation board. One end of the circuit board300is inserted into the housing assembly410, and the light-emitting assembly and the light-receiving assembly are electrically connected to the circuit board respectively, so that the light-emitting assembly realizes electro-optical conversion and emits signal light, so that the light-receiving assembly receives the signal light and realizes photoelectric conversion.

In the embodiment of the present disclosure, “above” refers to the direction of the upper housing201relative to the circuit board300, and “lower” refers to the direction of the lower housing202relative to the circuit board300. The inner cavity of the optical sub-module400is divided into a light-receiving cavity and a light-emitting cavity by a separation board, the light-receiving assembly is disposed in the light-receiving cavity, and the light-emitting assembly is disposed in the light-emitting cavity; a plurality of optical fiber adapters are provided on the left side of the optical sub-module400, the light-emitting assembly is connected with an optical fiber adapter, and the optical fiber adapter is used to transmit the signal light emitted by the light-emitting assembly to an external optical fiber to realize the emission of signal light; the light-receiving assembly is connected with another optical fiber adapter, and the optical fiber adapter is used to transmit the signal light transmitted by the external optical fiber into the light-receiving assembly to realize the reception of the signal light.

Since the size of the overall outline of the optical module must conform to the interface size of the host computer, which is regulated by industry standards, while the optical sub-module400is too bulky to be arranged on the circuit board300, one end of the circuit board300is inserted into the housing assembly410to realize the electrical connection between the optical sub-module400and the circuit board300; the circuit board300can also be separated from the optical sub-module400, and the transfer of the electrical connection can be realized through the flexible circuit board.

A light-receiving cavity and a light-receiving cover are provided in the upper part of the housing assembly410, and the light-receiving cover is covered on the light-receiving cavity from above; a collimating lens, a wavelength division demultiplexing component and other devices relating to light-receiving (also called as optical component(s)) are provided in the light-receiving cavity. An optical fiber adapter is provided on the left side of the housing assembly410, and one end of the light-receiving cavity is connected to the optical fiber adapter, and the signal light from the outside of the optical module is received through the optical fiber adapter, and the received signal light is transmitted to light-receiving chip through optical devices disposed in the light-receiving cavity such as the lens and the like. For example, the light-receiving assembly may include a lens assembly and a light-receiving chip, and a wavelength division demultiplexing component may be provided in the light-receiving cavity which is configured to demultiplex the beam comes from the optical fiber adapter into multiple beams of various wavelengths and transmit the demultiplexed multiple beams to the lens assembly through the light-passing holes; the lens assembly is arranged in the slot for converging the multiple beams transmitted through the light-passing holes into the light-receiving chip; and the light-receiving chip is arranged on an upper surface of the circuit plate inserted into the housing assembly and configured to receive the convergent beam from the lens assembly and convert the same into current signal.

A notch is provided on the side of the housing assembly410facing towards the circuit board300, and the circuit board300is inserted into the housing assembly410through the notch. Electrical devices such as a light-receiving chip, a transimpedance amplifier etc. located outside the housing assembly are provided on the surface of the circuit board300, the light beams transmitted through the optical lens such as a lens in the light-receiving cavity inject into the light-receiving chip on the circuit board300, and the photoelectric conversion is realized by the light-receiving chip.

In the optical module according to an embodiment of the present disclosure, the light-receiving assembly in the optical sub-module400is used to receive signal light of various wavelengths, the signal light of different wavelengths is transmitted into the light-receiving cavity through the optical fiber adapter, and realizes beam splitting according to wavelength through the optical devices such as wavelength division demultiplexing components (DeMUX) in the light-receiving cavity, the signal light after beam splitting according to wavelength is finally transmitted to the photosensitive surface of the corresponding light-receiving chip, and the light-receiving chip receives the signal light through its photosensitive surface. Typically, one light-receiving chip is used to receive signal light of one wavelength, thereby the light-receiving assembly according to an embodiment of the present disclosure comprises a plurality of light-receiving chips to form a chip array. For example, when the light-receiving assembly is used to receive signal light of four different wavelengths, the light-receiving assembly comprises four light-receiving chips for receiving the signal light of four wavelengths correspondingly; when the light-receiving assembly is used to receive the signal light of eight different wavelengths, the light-receiving assembly comprises eight light-receiving chips for receiving the signal light of the eight wavelengths correspondingly.

FIG.7is a schematic structural diagram of an optical sub-module400in an optical module according to an embodiment of the present disclosure. As shown inFIG.7, two groups of light-receiving assemblies are integrated into the optical sub-module400according to an embodiment of the present disclosure, and a first light-receiving cavity4101and a second light-receiving cavity4102are provided in the upper part of the housing assembly410. The first light-receiving cavity4101and the second light-receiving cavity4102are disposed side by side, that is, the first light-receiving cavity4101and the second light-receiving cavity4102are sequentially disposed along the width direction of the housing assembly410, with the first light-receiving cavity4101being arranged at one side in the width direction of the housing assembly410, and the second light-receiving cavity4102being arranged at the other side in the width direction of the housing assembly410. A first optical component is provided within the first light-receiving cavity4101. For example, the first optical component may include a first collimating lens and a first wavelength division demultiplexing component4201, and a first optical fiber adapter601is provided on a left side of the housing assembly410facing towards the optical port. The signal light transmitted by the first optical fiber adapter601is converted to a collimated beam via the first collimating lens, and the collimated beam is transmitted into the first wavelength division demultiplexing component4201; the collimated beam is divided into multiple signal lights of different wavelengths by the first wavelength division demultiplexing component4201. A second optical component is provided in the second light-receiving cavity4102. For example, the second optical component may include a second collimating lens and a second wavelength division demultiplexing component4202, and a second optical fiber adapter602is provided on the side of the housing assembly410facing towards the optical port. The signal light transmitted by the second optical fiber adapter602is converted into a collimated beam by the second collimating lens, and the collimated beam is transmitted into the second wavelength division demultiplexing component4202; the collimated beam is divided into multiple beams of signal light of different wavelengths by the second wavelength division demultiplexing component4202.

FIG.8is a working principle diagram of a DeMUX for beam splitting comprising four wavelengths (β1, β2, β3, and β4) according to an embodiment of the present disclosure. The wavelength division demultiplexing component comprises a light input port for inputting signal light of multiple wavelengths on one side, and comprises a plurality of light output ports for outputting light on the other side, each light output port is used for outputting signal light of one wavelength. For example, as shown inFIG.8, the signal light enters the DeMUX via the light input port at the right end of the DeMUX; the β1 signal light is reflected six times at six different positions of the DeMUX before reaching its light output port; the β2 signal light is reflected four times at four different positions of the DeMUX before reaching its light output port; the β3 signal light is reflected twice at two different positions of the DeMUX before reaching its light output port; the β4 signal light enters the DeMUX and is then directly transmitted to its light output port. In this way, by use of the DeMUX, signal lights of different wavelengths can enter the DeMUX through the same light input port and output through different light output ports, thereby realizing a beam splitting of a signal light of different wavelengths. In the embodiments of the present disclosure, DeMUX is not limited to using beam splitting comprising four wavelength beams, and can be selected according to actual needs.

FIG.9is a schematic structural diagram of a housing assembly410in an optical module according to an embodiment of the present disclosure, andFIG.10is schematic structural diagram from another angle of the housing assembly410in an optical module according to an embodiment of the present disclosure. As shown inFIG.9andFIG.10, a first through hole4112and a second through hole4113are provided on the left side wall of the housing assembly410, the first optical fiber adapter601is communicated with the first light-receiving cavity4104through the first through hole4112, the first collimating lens is disposed between the first through hole4112and the first wavelength division demultiplexing component4201; the second optical fiber adapter602is communicated with the second light-receiving cavity4102through the second through hole4113, and the second collimating lens is disposed between the second through hole4113and the second wavelength division demultiplexing component4202.

The first light-receiving cavity4101comprises a bottom plate and a side plate surrounding the bottom plate, and the bottom plate and the side plate form a cavity structure for containing the first collimating lens and the first wavelength division demultiplexing component4201. A first cover fixing glue groove4101ais provided on the top of the side plate of the first light-receiving cavity4101, thereby the first cover401can be fixedly connected to the first light-receiving cavity4101by glue. In some embodiments of the present disclosure, the first cover fixing glue groove4101aforms a closed-loop structure on the top of the side plate of the first light-receiving cavity4101, thereby the adhesive area of the first cover401on the top of the side plate of the first light-receiving cavity4101can be increased, ensuring sufficiently the packaging reliability of the first cover401and the top of the side plate of the first light-receiving cavity4101. In some embodiments of the present disclosure, a first repair port4101bis further provided on the top of the side plate of the first light-receiving cavity4101, the first repair port4101bis disposed on the top edge of the side plate of the first light-receiving cavity4101, and communicates with the first cover fixing glue groove4101a. When the inner devices in the first light-receiving cavity4101need to be repaired after the first cover401and the first light-receiving cavity4101were packaged, the first cover401can be removed from the first light-receiving cavity4101through the first repair port4101b, so that the first cover401can be removed without damaging the first cover401or the first light-receiving cavity4101, thereby reducing the difficulty and cost of repairing.

Similarly, the second light-receiving cavity4102comprises a bottom plate and a side plate surrounding the bottom plate, and the bottom plate and the side plate form a cavity structure for containing the second collimating lens and the second wavelength division demultiplexing component4202. A second cover fixing glue groove4102ais provided on the top of the side plate of the second light-receiving cavity4102, thereby the second cover402can be fixedly connected to the second light-receiving cavity4102by glue. In some embodiments of the present disclosure, the second cover fixing glue groove4102aforms a closed-loop structure on the top of the side plate of the second light-receiving cavity4102, thereby the adhesive area of the second cover402on the top of the side plate of the second light-receiving cavity4102can be increased, ensuring sufficiently the packaging reliability of the second cover402and the top of the side plate of the second light-receiving cavity4102. In some embodiments of the present disclosure, a second repair port4102bis further provided on the top of the side plate of the second light-receiving cavity4102, the second repair port4102bis disposed on the top edge of the side plate of the second light-receiving cavity4102, and communicates with the second cover fixing glue groove4102a. When the inner devices in the second light-receiving cavity4102need to be repaired after the second cover402and the second light-receiving cavity4102were packaged, the second cover402can be removed from the second light-receiving cavity4102through the second repair port4102b, so that the second cover402can be removed without damaging the second cover402or the second light-receiving cavity4102, thereby reducing the difficulty and cost of repairing.

In some embodiments, a first DeMUX fixing glue groove4108is provided on the bottom plate of the first light-receiving cavity4101, and the first DeMUX fixing glue groove4108is used to hold dispensing glue. For example, when the first wavelength division demultiplexing component4201needs to be fixed, glue is dispensed into the first DeMUX fixing glue groove4108, and then the first wavelength division demultiplexing component4201is installed and placed on the first DeMUX fixing glue groove4108; after the glue is solidified, a fixing of the first wavelength division demultiplexing component4201on the bottom plate is realized. Similarly, the second DeMUX fixing glue groove4110is used to hold the dispensing glue. For example, when the second wavelength division demultiplexing component4202needs to be fixed, glue is dispensed into the second DeMUX fixing glue groove4110, and then the second wavelength division demultiplexing component4202is installed and placed on the second DeMUX fixing glue groove4110; after the glue is solidified, a fixing of the second wavelength division demultiplexing component4202on the bottom plate is realized.

The DeMUX fixing glue groove formed on the bottom surface of the light-receiving cavity has an annular, protuberant circumference. The circumference is of a closed shape, so that the glue groove is delimited by the closed circumference. The wavelength division demultiplexing component is disposed onto the annular, protruded circumference. Glue is provided into the groove enclosed by the annular, protuberant circumference for adhering the wavelength division demultiplexing component.

In the embodiments of the present disclosure, a first light-receiving assembly430and a second light-receiving assembly440are disposed in the light-receiving portion side by side. For example, a first slot4103and a second slot4104are provided on the side of the housing assembly410facing towards the circuit board300, and the first slot4103and the second slot4104are sequentially disposed along the width direction of the housing assembly410, wherein both the upper side and right side of the first slot4103and the second slot4104are open, with the first slot4103and the second slot4104being separated by the separation board4111. A first light-receiving assembly430is provided inside of the first slot4103, and a second light-receiving assembly440is provided inside the second slot4104. Taking the receiving of light of eight wavelengths comprising two wavelength bands as an example, a single wavelength band comprises light of four wavelengths, wherein, the signal light transmitted by the first optical fiber adapter601may be transmitted to the first light-receiving assembly430via the first optical component, for example, it may be converted into a collimated beam through the first collimating lens, and the collimated beam then demultiplexes a collimated beam into four beams of different wavelengths via the first wavelength division demultiplexing component4201, the four beams of different wavelengths are respectively transmitted to the first light-receiving assembly430, and the first light-receiving assembly430realizes the photoelectric conversion; the signal light transmitted by the second optical fiber adapter402may be transmitted to the second light-receiving assembly440via the second optical component, for example, it may be converted into a collimated beam through the second collimating lens, and the collimated beam then demultiplexes a collimated beam into four beams of different wavelengths via the second wavelength division demultiplexing component4202, the four beams of different wavelengths are respectively transmitted to the second light-receiving assembly440, and photoelectric conversion is realized by the second light-receiving assembly440.

FIG.11is a partial cross-sectional view of a housing assembly410in an optical module according to an embodiment of the present disclosure. As shown inFIG.11, the first light-receiving cavity4101and the first slot4103may be communicated through light-passing holes4109; that is, the first light-receiving cavity4101and the first slot4103are separated by a partition wall, with a plurality of light-passing holes4109being provided in the partition wall; the multiple beams of different wavelengths demultiplexed and output through the first wavelength division demultiplexing component4201in the first light-receiving cavity4101are transmitted to the first light-receiving assembly430via the corresponding light-passing holes4109. Similarly, the second light-receiving cavity4102and the second slot4104may be communicated through the light-passing holes, that is, the second light-receiving cavity4102and the second slot4104are separated by the partition wall provided with the light-passing holes4109; the multiple beams of different wavelengths demultiplexed and output through the second wavelength division demultiplexing component4202in the second light-receiving cavity4102are transmitted to the second light-receiving assembly440via the corresponding light-passing holes4109.

In the embodiments of the present disclosure, the first wavelength division demultiplexing component4201is used to demultiplex one beam into four beams of different wavelengths. Therefore, four light-passing holes4109are provided between the first light-receiving cavity4101and the first slot4103, the four light-passing holes4109are sequentially disposed along the width direction of the housing assembly410, and the four light output ports of the first wavelength division demultiplexing component4201are disposed in one-to-one correspondence with the four light-passing holes4109, so that the four beams of different wavelengths demultiplexed and output from the first wavelength division demultiplexing component4201are respectively transmitted to the first light-receiving assembly430through the corresponding light-passing holes4109. Similarly, the second wavelength division demultiplexing component4202is used to demultiplex one beam into four beams of different wavelengths. Therefore, four light-passing holes4109are provided between the second light-receiving cavity4102and the second slot4104, the four light-passing holes4109are sequentially disposed along the width direction of the housing assembly410, and the four light output ports of the second wavelength division demultiplexing component4202are disposed in one-to-one correspondence with the four light-passing holes4109, so that the four beams of different wavelengths demultiplexed and output from the second wavelength division demultiplexing component4202are respectively transmitted to the second light-receiving assembly440through the corresponding light-passing holes4109.

In the embodiments of the present disclosure, the first light-receiving cavity4101and the first slot4103can also be directly communicated into an integrated cavity, and a first collimating lens and the first wavelength division demultiplexing component4201are provided on the side of the integrated cavity close to the first optical fiber adapter601, the first light-receiving assembly430is disposed on the side of the integrated cavity close to the circuit board300, so that the signal light transmitted by the first optical fiber adapter601is converted to collimated beam through the first collimating lens, the collimated beam is demultiplexed into four beams with different wavelengths via the first wavelength division demultiplexing component4201, and the four beams of different wavelengths are directly transmitted to the first light-receiving assembly430. Similarly, the second light-receiving cavity4102and the second slot4104can also be directly communicated into an integrated cavity, and a second collimating lens and the second wavelength division demultiplexing component4202are provided on the side of the integrated cavity close to the second optical fiber adapter602, the second light-receiving assembly440is disposed on the side of the integrated cavity close to the circuit board300, so that the signal light transmitted by the second optical fiber adapter602is converted to collimated beam through the second collimating lens, the collimated beam is demultiplexed into four beams with different wavelengths via the second wavelength division demultiplexing component4202, and the four beams of different wavelengths are directly transmitted to the second light-receiving assembly440.

Compared with communicating the first light-receiving cavity4101and the first slot4103into an integrated cavity, the way of the first light-receiving cavity4101communicating with the first slot4103through the light-passing hole4109can reduce the processing of the housing assembly410, and the structure of the housing assembly410is more retained, so that the heat generated by the optoelectronic devices of the light-receiving assembly and the optoelectronic devices of the light-emitting assembly is conducted to the upper housing201and the lower housing202through where has no drilling on the housing assembly410, therefore increasing the heat dissipation efficiency of the optical sub-module400.

FIG.12is a schematic structural diagram of a light-receiving assembly in an optical sub-module400in an optical module according to an embodiment of the present disclosure, and FIG.13is a schematic diagram of an optical path of a light-receiving assembly in the optical sub-module400in an optical module according to an embodiment of the present disclosure Schematic. As shown inFIG.12andFIG.13, the first light-receiving assembly430and the second light-receiving assembly440respectively comprise several light-receiving chips, which are PDs (photodetectors), such as APDs (avalanche diodes), for converting the received signal light into photocurrent. In some embodiments of the present disclosure, the light-receiving chips in the first light-receiving assembly430and the second light-receiving assembly440are respectively disposed on the surface of the metallized ceramic which forms a circuit pattern that can supply power to the light-receiving chip. Then, the metallized ceramic provided with the light-receiving chip is applied on the circuit board300, or the light-receiving chip is applied on the flexible circuit board which is electrically connected with the circuit board300.

In the embodiments of the present disclosure, the first light-receiving assembly430and the second light-receiving assembly440further comprise transimpedance amplifiers, respectively, the transimpedance amplifiers are directly applied on the circuit board300, are connected to the corresponding light-receiving chips, and receive the current signal generated by the light-receiving chip and convert the received current signal into a voltage signal. In some embodiments of the present disclosure, the transimpedance amplifiers are connected to the corresponding light-receiving chip by means of wire adhering, such as a semiconductor gold wire adhering (Gold Wire Bonding).

In some embodiments of the present disclosure, the light-receiving assembly further includes a ceramic substrate and a transimpedance amplifier disposed on the upper surface of the circuit board300, the light-receiving chip is arranged on the ceramic substrate, the transimpedance amplifier is located at a side of the ceramic substrate and is connected to the ceramic substrate via wire bonding. The ceramic substrate is configured to raise the light-receiving chip such that electrodes of the light-receiving chip and pins on the transimpedance amplifier are on the same plane. For example, the first light-receiving assembly430comprises a first ceramic substrate4304and a first transimpedance amplifier4305. The first transimpedance amplifier4305is placed on one side of the first ceramic substrate4304, as shown inFIG.13, the first transimpedance amplifier4305is located on the right side of the first ceramic substrate4304. Wherein, four first light-receiving chips4303are provided on the first ceramic substrate4304, and the first ceramic substrate4304is connected to the first transimpedance amplifier4305by wire adhering, so as to achieve the connection of the first light-receiving chip4303and the first transimpedance amplifier4305. The longer the length of the wire adhering is, the larger the inductance generated by the wire adhering will be, and the signal mismatch will also be larger, while the signal output from the first light-receiving chip4303is a small signal, which will in turn cause the signal quality to deteriorate. Therefore, the first light-receiving chip4303and the first transimpedance amplifier4305are disposed as close as possible to reduce the length of the wire adhering and ensure the signal transmission quality, and then the first transimpedance amplifier4305is disposed on one side of the first ceramic substrate4304to cause the first ceramic substrate4304be disposed as close to the transimpedance amplifier4305as possible.

In the embodiments of the present disclosure, the first ceramic substrate4304is also used to elevate the first light-receiving chip4303, so that the electrodes of the first light-receiving chip4303and the pins on the first transimpedance amplifier4305are on the same plane, ensuring that the wire adhering between the first light-receiving chip4303and the first transimpedance amplifier4305is the shortest.

Similarly, the second light-receiving assembly440comprises a second ceramic substrate4404and a second transimpedance amplifier4405. The second transimpedance amplifier4305is placed on one side of the second ceramic substrate4404, that is, the second transimpedance amplifier4405is located on the right side of the second ceramic substrate4404. Wherein, four second light-receiving chips4403are provided on the second ceramic substrate4404, and the second ceramic substrate4404is connected to the second transimpedance amplifier4405by wire adhering, so as to achieve the connection of the second light-receiving chip4403and the second transimpedance amplifier4405. The longer the length of the wire adhering is, the larger the inductance generated by the wire adhering will be, and the signal mismatch will also be larger, while the signal output from the second light-receiving chip4403is a small signal, which will in turn causes the signal quality to deteriorate. Therefore, the second light-receiving chip4403and the second transimpedance amplifier4405are disposed as close as possible to reduce the length of the wire adhering and ensure the signal transmission quality, and then the second transimpedance amplifier4405is disposed on one side of the second ceramic substrate4404to cause the second ceramic substrate4404be disposed as close to the transimpedance amplifier4405as possible.

In the embodiments of the present disclosure, the second ceramic substrate4404is also used to elevate the second light-receiving chip4403, so that the electrodes of the second light-receiving chip4403and the pins on the second transimpedance amplifier4405are on the same plane, ensuring that the adhering wire between the second light-receiving chip4403and the second transimpedance amplifier4405is the shortest.

In the embodiments of the present disclosure, if the pins of the transimpedance amplifier are sufficient, the first transimpedance amplifier4305and the second transimpedance amplifier4405can use one transimpedance amplifier chip, and furthermore, four first light-receiving chips4303and four second light-receiving chip4403may be disposed on one ceramic substrate.

In order to facilitate the light-receiving chip to receive the signal light, the first light-receiving assembly430further comprises a first lens assembly4301, and the first lens assembly4301is used to adjust the optical path in the process of transmitting the four beams of different wavelengths output from the first wavelength division demultiplexing component4201to the first light-receiving assembly430; the second light-receiving assembly440further comprises a second lens assembly4401, and the second lens assembly4401is used to adjust the optical path in the process of transmitting the four beams of different wavelengths output from the second wavelength division demultiplexing component4202to the second light-receiving assembly440.

In the embodiments of the present disclosure, the optical axis of the first lens assembly4301is parallel to the bottom surface of the first slot4103, while the photosensitive surface of the first light-receiving chip4301is also parallel to the bottom surface of the first slot4103, but the first light receiving chip4301is disposed on the upper surface of the circuit board300, and there is a latitude difference between the bottom surface of the first slot4103and the upper surface of the circuit board300. Therefore, in order to ensure that the first light-receiving chip4301receives the signal light normally, the first light-receiving assembly430further comprises a first reflective mirror4302, the first reflective mirror4302is disposed above the first ceramic substrate4304and covers the four first light-receiving chips4303disposed on the first ceramic substrate4304, changing the direction of the optical axis of the signal light emitted by the first lens assembly4301by means of the reflective surface of the first reflective mirror4302, so that the optical axis of the signal light emitted by the first lens assembly4301is converted from a bottom surface parallel to the first slot4103to a bottom surface perpendicular to the first slot4103, so that the signal light is vertically incident onto the photosensitive surface corresponding to the first light-receiving chip4303.

The signal light transmitted to the first light-receiving cavity4101via the first optical fiber adapter601is converted into a collimated beam after passing through the first collimating lens, and the collimated beam is incident into the first wavelength division demultiplexing component4201, a collimated beam is demultiplexed into four beams of different wavelengths via the second wave demultiplexing component4201, and the four beams of different wavelengths are transmitted to the first slot4103through the corresponding light holes4109, respectively, are focused via the corresponding lenses, and then transmitted to the first reflective mirror4302. When the four beams of different wavelengths are transmitted to the reflective surface of the first reflective mirror4302, they are reflected by the reflective surface of the first reflective mirror4302, so that the transmission direction of the light beam is changed from the direction parallel to the bottom surface of the first slot4103to the direction perpendicular to the bottom surface of the first slot4302, and the four beams are respectively transmitted to the corresponding first light-receiving chip4303on the first ceramic substrate4304below the reflective surface of the first reflective mirror4302after the direction changing, photoelectric conversion is realized by the first light-receiving chip4303.

Similarly, the optical axis of the second lens assembly4401is parallel to the bottom surface of the second slot4104, while the photosensitive surface of the second light-receiving chip4401is also parallel to the bottom surface of the second slot4104, but the second light receiving chip4401is disposed on the upper surface of the circuit board300, and there is a height difference between the bottom surface of the second slot4104and the upper surface of the circuit board300. Therefore, in order to ensure that the second light-receiving chip4401receives the signal light normally, the second light-receiving assembly440comprises a second reflective mirror4402, the second reflective mirror4402is disposed above the second ceramic substrate4404and covers the four second light-receiving chips44303disposed on the second ceramic substrate4404, changing the direction of the optical axis of the signal light emitted by the second lens assembly4401by means of the reflective surface of the second reflective mirror4402, so that the optical axis of the signal light emitted by the second lens assembly4401is converted from a bottom surface parallel to the second slot4104to a bottom surface perpendicular to the second slot4104, so that the signal light is vertically incident onto the photosensitive surface corresponding to the second light-receiving chip4403

FIG.14is a cross-sectional view of the second light-receiving assembly440in the housing assembly410in an optical module according to an embodiment of the present disclosure, andFIG.15is an assembly cross-sectional view of a second light-receiving assembly440, a housing assembly410and a circuit board300in an optical module according to an embodiment of the present disclosure. As shown inFIG.14andFIG.15, the signal light transmitted to the second light-receiving cavity4102via the second optical fiber adapter602is converted into a collimated beam after passing through the first collimating lens, and the collimated beam is incident into the second wavelength division multiplexing component4202, a collimated beam is demultiplexed into four beams of different wavelengths via the second wavelength demultiplexing component4202, and the four beams of different wavelengths are transmitted to the corresponding lenses of the second lens assembly4401in the second slot4104through the corresponding light holes4109, respectively, are focused via the corresponding lenses, and then transmitted to the second reflective mirror4402. When the four beams of different wavelengths are transmitted to the reflective surface of the second reflective mirror4402, they are reflected by the reflective surface of the second reflective mirror4402, so that the transmission direction of the light beam is changed from the direction parallel to the bottom surface of the second slot4104to the direction perpendicular to the bottom surface of the second slot4402, and the four beams are respectively transmitted to the corresponding second light-receiving chip4402on the second ceramic substrate4404below the reflective surface of the second reflective mirror4403after the direction changing, photoelectric conversion is realized by the second light-receiving chip4403.

In the embodiments of the present disclosure, the first reflective mirror4302and the second reflective mirror4402are both 45° reflective mirrors, that is, the first reflective mirror4302and the second reflective mirror4402respectively comprise a 45° reflection surface, with the 45° reflective surface of the first reflective mirror4302capping the four first light-receiving chips4303provided on the first ceramic substrate4304, and the 45° reflective surface of the second mirror4402capping the four second light-receiving chips4403provided on the second ceramic substrate4404.

Since the first slot4103and the second slot4104are slots opened upwardly, in order to protect the first lens assembly4301and the first reflective mirror4302in the first slot4103as well as the second lens assembly4401and the second reflective mirror4403in the second slot4104, the first slot4103and the second slot4104are covered with a covering hood500, wherein the left side and the lower side of the covering hood500are both open, the left side of the covering hood500is connected with the partition wall of the housing, and the opening at the lower side of the covering hood500is in contact with an upper surface of the circuit board.

After the first lens assembly4301and the first reflective mirror4302is installed in the first slot4103according to the optical path of the first light-receiving assembly430, and the second lens assembly4401and the second reflective mirror4402is installed in the second slot4104according to the light path of the second light-receiving assembly440, the covering hood500is covered onto the first slot4103, the second slot4104and the light-receiving chips; the lower opening of the covering hood500is in contact with the upper surface of the circuit board300. The upper surface and two side surfaces in the width direction of the covering hood500are respectively in the same planes as the upper surface, two side surfaces in the width direction of the housing assembly410, so that the first slot4103and the second slot4104cooperate with the covering hood500to form cavities for placing the first light-receiving assembly430and the second light-receiving assembly440.

A first notch4114is provided at the side of the housing assembly410approximate to the circuit board300; the first notch4114is located underneath the first slot4103and the second slot4104, and the bottom surface of the first notch4114is parallel to the bottom surfaces of the first slot4103and the second slot4104, so that when one end of the circuit board300is inserted into the first notch4114, the surfaces of the circuit board300are parallel to the bottom surfaces of the first slot4103and the second slot4104, and the first ceramic substrate4304, the first transimpedance amplifier4305, the second ceramic substrate4404and the second transimpedance amplifier4405provided on the circuit board300are also parallel to the bottom surfaces of the first slot4103and the second slot4104; by this, the beam focused by the first lens assembly4301may be reflected by the first reflective mirror4302to the corresponding first light-receiving chip4303on the first ceramic substrate4304, and the beam focused by the second lens assembly4401may be reflected by the second reflective mirror4402to the corresponding second light-receiving chip4403on the second ceramic substrate4404.

A second notch is provided between the first notch4114and the bottom surfaces of the first slot4103and the second slot4104, the lower side of the second notch being in communication with the first notch4114, and the right side of the second notch is opened; an aluminum nitride ceramic substrate800is provided in the second notch, with the aluminum nitride ceramic substrate800being in contact with the inner walls of the second notch and the upper surface of the circuit board300, respectively. In some embodiments of the present disclosure, an upper surface of the aluminum nitride ceramic substrate800is in contact with an upper sidewall of the second notch, while a lower surface of the aluminum nitride ceramic substrate800is in contact with the upper surface of the circuit board300, and gaps between the aluminum nitride ceramic substrate800and housing assembly410as well as gaps between the aluminum nitride ceramic substrate800and the circuit board300are filled with insulating high thermal conductivity glue. As shown in the heat conduction path, the heat generated by the first light-receiving chip4303is conducted to the circuit board300through the first ceramic substrate4304, the heat generated by the first transimpedance amplifier4305is directly conducted to the circuit board300; the heat generated by the second light-receiving chip4403is conducted to the circuit board300through the second ceramic substrate4404, the heat generated by the second transimpedance amplifier4405is directly conducted to the circuit board300; meanwhile, the heat conducted to the circuit board300is conducted to housing assembly410through the copper cladding on the circuit board300and the aluminum nitride ceramic substrate800, and then conducted to the upper casing201and the lower casing202of the optical module through the housing assembly410for heat dissipation, which improves heat dissipation efficiency of the light-receiving assembly integrated in the optical sub-module400.

The first transimpedance amplifier4305and the second transimpedance amplifier4405are provided on the circuit board300; the first transimpedance amplifier4305may also be arranged on a heat sink, and then the heat sink is provided on the upper surface of the circuit board300, so that the heat sink can not only conduct the heat generated by the first transimpedance amplifier4305to the circuit board300, but also elevate the first transimpedance amplifier4305, so that the first transimpedance amplifier4305and the first light-receiving chip4303may be located on the same plane/in the same level. Similarly, the second transimpedance amplifier4405can also be arranged on a heat sink, and then the heat sink can be provided on the upper surface of the circuit board300, so that the heat sink can not only conduct the heat generated by the second transimpedance amplifier4405to the circuit board300, but also elevate the second transimpedance amplifier4405, so that the second transimpedance amplifier4405and the second light-receiving chip4403may be located on the same plane/in the same level.

In the embodiments of the present disclosure, the optical sub-module400includes both a light-receiving assembly and a light-emitting assembly, with the light-receiving assembly and the light-emitting assembly being separated by a separation board; the light-receiving assembly is integrated above the separation board, and the light-emitting assembly is integrated below the separation board.

FIG.16is a schematic assembly diagram from another angle of view for the circuit board300and the optical sub-module400in an optical module according to an embodiment of the present disclosure,FIG.17is a schematic assembly diagram from a further angle of view for the circuit board300and the optical sub-module400in an optical module according to an embodiment of the present disclosure, andFIG.18is a schematic partial exploded diagram of the circuit board300and the optical sub-module400in an optical module according to an embodiment of the present disclosure. As shown inFIG.16,FIG.17, andFIG.18, a light-emitting cavity and a light-emitting cover403are provided at the lower portion of the housing assembly410, wherein the light-emitting cover403covers the light-emitting cavity from below, and photoelectric devices related to light-emitting, such as lenses and light-emitting chips, are provided within the light-emitting cavity. The first notch4114is provided at the side of the housing assembly410facing towards the circuit board300, the circuit board300is inserted into the housing assembly410through the first notch4114, a pad is provided on the lower surface of the circuit board, and the light-emitting assembly is connected to the pad through wires, so that the electrical devices such as light-emitting chips disposed within the light-emitting cavity are electrically connected with the circuit board300to drive the light-emitting chip so as to realize electro-optical conversion.

In the optical module provided by the embodiments of the present disclosure, the light-emitting assembly in the optical sub-module400is used to emit signal lights of multiple different wavelengths, and the signal lights of different wavelengths achieve light multiplexing through optics such as a wavelength division multiplexing component (MUX) in the light-emitting cavity, and the combined, multiplexed light beam is transmitted to the external optical fiber through the optical fiber adapter to realize an emission of signal light. Typically, one light-emitting chip is used to emit signal light of one wavelength, and the light-emitting assembly according to the embodiment of the present disclosure comprises a plurality of light-emitting chips to form a chip array. For example, when the light-emitting assembly is used to emit signal lights of four different wavelengths, the light-emitting assembly comprises four light-emitting chips for correspondingly emitting signal lights of four different wavelengths; when the light-emitting assembly is used to emit signal lights of eight different wavelengths, the light-emitting assembly comprises eight light-emitting chips for correspondingly emitting signal lights of eight wavelengths.

FIG.19is another schematic structural diagram of a housing assembly410in an optical module according to an embodiment of the present disclosure. As shown inFIG.19, in the light-emitting assembly in the optical sub-module400, the light-emitting cavity4115houses/accommodates optical devices such as the wavelength division multiplexing component460, and the light beams of multiple different wavelengths emitted by the light-emitting chips are transmitted to the wavelength division multiplexing component460, which multiplexes light beams of multiple different wavelengths into a composite, multiplexed light beam which is transmitted into an external optical fiber through an optical fiber adapter.

In the embodiments of the present disclosure, four light input ports for incident signal lights of multiple wavelengths are provided the on the right side of the wavelength division multiplexing component460, and one light output port for emitting light is provided on the left side; each light input port is used for incident signal light of one wavelength. In some embodiments of the present disclosure, signal lights of multiple different wavelengths enter the wavelength division multiplexing component460through corresponding light input ports, wherein one beam of signal light is reflected six times at six different positions of the wavelength division multiplexing component460before reaching the light output port, one beam of signal light is reflected four times at four different positions of the wavelength division multiplexing component460before reaching the light output port, one beam of signal light is reflected twice at two different positions of the wavelength division multiplexing component460before reaching the light output port, and one beam of signal light is incident onto the wavelength division multiplexing component460and then directly transmitted to the light output port. In this way, the wavelength division multiplexing component realizes that signal lights of different wavelengths enter the wavelength division multiplexing component via different light input ports, and are output via the same light output port, thereby obtaining a beam consisted of signal lights of different wavelengths. In the embodiments of the present disclosure, the wavelength division multiplexing component is not limited to a beam multiplexing of four wavelengths, and can be designed according to actual needs.

Two groups of light-emitting assemblies are integrated in the optical sub-module400according to an embodiment of the present disclosure, and a light-emitting cavity4115is provided in the lower part of the housing assembly410, converging lens, wavelength division multiplexing components460, and light-emitting assemblies are provided in the light-emitting cavity4115; an optical fiber adapter is provided on the left side of the housing assembly410, and the optical fiber adapter is communicated with the light-emitting cavity4115. The wavelength division multiplexing component460is disposed at a side of the light-emitting cavity4115approximate to the optical fiber adapter, the light-emitting assembly is disposed at a side of the light-emitting cavity4115close to the circuit board300, and the converging lens is disposed between the optical fiber adapter and the wavelength division multiplexing component460. Signal lights of multiple different wavelengths emitted by the light-emitting assembly are thereby transmitted to the wavelength division multiplexing component460, the multiple light beams of different wavelengths are multiplexed into a composite, multiplexed light beam via the wavelength division multiplexing component460, and the multiplexed light beam is coupled to the optical fiber adapter via the converging lens, thereby realizing an emission of lights of multiple different wavelengths.

FIG.20is a schematic structural diagram of a light-emitting assembly in an optical sub-module400in an optical module according to an embodiment of the present disclosure, andFIG.21is a schematic diagram of an optical path of the light-emitting assembly in an optical module according to an embodiment of the present disclosure. As shown inFIG.20andFIG.21, the light-emitting cavity4115comprises a top plate provided at the top of the cavity and side plates surrounding the top plate. The top plate and the side plates form a cavity structure for accommodating the wavelength division multiplexing component460and the light transmitting components. The light transmitting components comprises a first light-emitting assembly470and a second light-emitting assembly480that are provided at the side of the light-emitting cavity4115approximate to the circuit board300, and are electrically connected to the circuit boards300, respectively. The wavelength division multiplexing component460provided in the light-emitting cavity4115comprises a first wavelength division multiplexing component4601and a second wavelength division multiplexing component4602, and a third optical fiber adapter603and a fourth optical fiber adapter604is provided at the left side of the housing assembly410; the third optical fiber adapter603extends into the light-emitting cavity4115, and a first convergence lens701is provided between the third optical fiber adapter603and the first wavelength division multiplexing component4601; a second converging lens702is provided between the fourth optical fiber adapter604and the second wavelength division multiplexing components4602. In this way, signal lights of four different wavelengths emitted by the first light-emitting assembly470are transmitted to the first wavelength division multiplexing component4601, and the four beams of signal light of different wavelengths are multiplexed into a composite, multiplexed beam via the first wavelength division multiplexing component4601; the multiplexed light beam is converged and coupled to the third optical fiber adapter603via the first converging lens701. Similarly, signal lights of four different wavelengths emitted by the second light-emitting assembly480are transmitted to the second wavelength division multiplexing component4602, and the four beams of signal light of different wavelengths are multiplexed into a composite, multiplexed beam via the second wavelength division multiplexing component4602; the composite light beam is converged and coupled to the fourth optical fiber adapter604via the second converging lens702.

The first optical fiber adapter and the third optical fiber adapter are provided at different levels. The second optical fiber adapter and the fourth optical fiber adapter are provided at different levels.

In the embodiments of the present disclosure, the first light-emitting assembly470and the second light-emitting assembly480comprise a plurality of light-emitting chips, respectively, and the light-emitting chips are laser chips for converting a current signal into laser light for emission. In some embodiments of the present disclosure, the first light-emitting assembly470comprises a third lens assembly4701and a first laser assembly4702for emitting multiple signal light beams of different wavelengths; the third lens assembly4701is provided in a light emission direction from the first laser assembly4702for converting the beam emitted by the first laser assembly4702into a collimated beam; the first wavelength division multiplexing component4601is disposed in a light emission direction from the third lens assembly4701for multiplexing multiple beams of different wavelengths into a composite, multiplexed beam; the first converging lens701is disposed in the light emission direction from the first wavelength division multiplexing component4601, in order that a multiplexed beam emitted by the first wavelength division multiplexing component4601may be converged and coupled into the third fiber adapter603for emission.

Similarly, the second light-emitting assembly480comprises a fourth lens assembly4801and a second laser assembly4802for emitting multiple signal light beams of different wavelengths, and the fourth lens assembly4801is provided in the light emission direction from the second laser assembly4802for converting the beam emitted by the second laser assembly4802into a collimated beam; the second wavelength division multiplexing component4602is disposed in the light emission direction from the fourth lens assembly4801for multiplexing multiple beams of different wavelengths into a composite, multiplexed beam; the second converging lens702is disposed in the light emission direction from the second wavelength division multiplexing component4602, in order that the multiplexed beam emitted by the second wavelength division multiplexing component4601is converged and coupled into the fourth fiber adapter604for emission.

In the embodiments of the present disclosure, the first laser assembly4702may comprise four lasers, the third lens assembly4701may comprise four collimating lenses, with the four lasers being provided in a one-to-one correspondence with the four collimating lenses, such that the four lasers emit four beams of different wavelengths, respectively, which are respectively transmitted to the corresponding collimating lenses. Correspondingly, the second laser assembly4802may comprise four lasers, the fourth lens assembly4801may comprise four collimating lenses, with the four lasers being provided in a one-to-one correspondence with the four collimating lenses, such that the four lasers emit four beams of different wavelengths, respectively, which are respectively transmitted to the corresponding collimating lenses.

The first wavelength division multiplexing component4601and the second wavelength division multiplexing component4602both comprise four input channels; the four collimated light beams output from the four collimating lenses of the third lens assembly4701enter the four input channels of the first wavelength division multiplexing component4601, respectively. The first wavelength division multiplexing component4601converts the collimated beams of the four channels into a composite, multiplexed beam that is converged and coupled to the third fiber adapter603through the first converging lens701, so as to achieve an emission of a 4-channel wavelength division multiplexed light. Similarly, the four collimated light beams output from the four collimating lenses of the fourth lens assembly4702enter the four input channels of the second wavelength division multiplexing component4602, respectively. The second wavelength division multiplexing component4602converts the collimated beams of the four channels into a composite, multiplexed beam that is converged and coupled to the fourth fiber adapter604through the second converging lens702, so as to achieve an emission of a 4-channel wavelength division multiplexed light. In this way, the present disclosure multiplexes the 8-channel light beams into two composite, multiplexed light beams through two wavelength division multiplexing components and couples the two multiplexed light beams into the two optical fiber adapters respectively, thereby reducing the volume occupied by the light-emitting assembly in the optical module, which is advantageous for a miniaturization of optical modules.

In the embodiments of the present disclosure, in order to realize the emission optical path of the above-mentioned embodiment, it is necessary to provide a platform for device supporting and coupling for the first light-emitting assembly470, the first wavelength division multiplexing component4601, the second light-emitting assembly480and the second wavelength division multiplexing component4602, so as to realize a passive coupling of the first light-emitting assembly470with the first wavelength division multiplexing component4601as well as a passive coupling of the second light-emitting assembly480with the second wavelength division multiplexing component4602, thus reduce a coupling difficulty of the emission optical path.

FIG.22is a schematic structural diagram from another angle of view for a housing assembly410in an optical module according to an embodiment of the present disclosure. As shown inFIG.22, in some examples, a top plate of the light-emitting cavity4115is formed with a concave region recessed towards the light-receiving portion. For example, a first top surface4115cand a second top surface4116are formed on the top plate of the light-emitting cavity4115that is formed in the lower part of the housing assembly410, and a step is formed between the first top surface4115cand the second top surface4116, that is, there is a height difference between the first top surface4115cand the second top surface4116, and the second top surface4116is positioned at a level higher than the first top surface4115c, and thus the concave region is formed below the second top surface4116. A first MUX fixing glue groove4117and a second MUX fixing glue groove4118are provided on the first top surface4115c; the top surface of the light-emitting cavity forms MUX fixing glue grooves having an annular, protuberant circumference on which the wavelength division multiplexing component is disposed. Glue is provided into the groove enclosed by the annular, protuberant circumference for adhering the wavelength division multiplexing component. The first wavelength division multiplexing component4601is fixed on the first top surface4115cby means of the first MUX fixing glue groove4117, and the second wavelength division multiplexing component4602is fixed on the first top surface4115cby means of the second MUX fixing glue groove4118. In some embodiments of the present disclosure, the first MUX fixing glue groove4117is used for dispensing glue. When the first wavelength division multiplexing component4601needs to be fixed, glue is dispensed into the first MUX fixing glue groove4117, and then the first wavelength division multiplexing component4601is placed and arranged into the first MUX fixing glue groove4117, and a fixing of the first wavelength division multiplexing component4601on the first top surface4115cis achieved when the glue solidifies. Similarly, the second MUX fixing glue groove4118is used for dispensing glue. When the second wavelength division multiplexing component4602needs to be fixed, glue is dispensed into the second MUX fixing glue groove4118, and then the second wavelength division multiplexing component4602is placed and arranged into the second MUX fixing glue groove4118, and a fixing of the second wavelength division multiplexing component4602on the first top surface4115cis achieved when the glue solidifies.

In some examples, the light-emitting assembly is arranged in the concave region of the top plate, for example, the laser assembly of the light-emitting assembly is arranged in the concave region. For example, the second top surface4116is provided for carrying the first light-emitting assembly470and the second light-emitting assembly480, and for example, the second top surface4116is configured for carrying the first laser assembly4702of the first light-emitting assembly470and the second laser assembly4802of the second light-emitting assembly480. In order to ensure that a height of the emission channel of the first laser assembly470is the same/consistent with a height of the input channel of a wavelength division multiplexing component4601, and a height of the emission channel of the second laser assembly480is the same/consistent with a height of the input channel of the second wavelength division multiplexing component4602, a semiconductor refrigerator490is provided on the second top surface4116, a top surface (upper surface) of the semiconductor refrigerator490is affixed onto the second top surface4116, and a bottom surface (lower surface) thereof is configured to support and secure the first light-emitting assembly470as well as the second light-emitting assembly480, so that heat generated by the first light-emitting assembly470and the second light-emitting assembly480may be conducted/transferred to the semiconductor refrigerator490, thus realizing an effective heat dissipation of the light-emitting assembly.

The step between the first top surface4115cand the second top surface4116realizes a height difference in the top surface of the light-emitting cavity4115. On one hand, by the step formed between the first top surface4115cand the second top surface4116, a mounting surface for the semiconductor refrigerator490may be lifted by the second top surface4116, thereby lifting the first light-emitting assembly470and the second light-emitting assembly480, so as to facilitate an assembly of the first light-emitting assembly470, the first wavelength division multiplexing component4601, the second light-emitting assembly480, and the second wavelength division multiplexing component4602. For example, the light-emitting assembly, for example, the first laser assembly4702of the first light-emitting assembly470, may be disposed on the top surface of the concave region so as to lift the first laser assembly4702to thereby reduce height difference between wire bonding surface of the first laser assembly4702and the lower surface of the circuit board300. In this way, the length of wire bonding between the wire bonding surface of the first laser assembly4702and the lower surface of the circuit board300may be shortened. Similarly, the light-emitting assembly, for example, the second laser assembly4802of the second light-emitting assembly480may be disposed on the top surface of the concave region so as to lift the second laser assembly4802to thereby reduce height difference between wire bonding surface of the second laser assembly4802and the lower surface of the circuit board300. In this way, the length of wire bonding between the wire bonding surface of the second laser assembly4802and the lower surface of the circuit board300may be shortened. On the other hand, the step can also be used for limiting the position of the semiconductor refrigerator490.

The notch4114is provided at a side of the housing assembly410approximate to the circuit board300, which is wrapped around an outside of the second top surface4116; a notch310(referred to as a third notch310hereinafter, so as to be differentiated from other notches such as the first notch4114) is provided in the circuit board300, at a side facing towards the housing assembly410; when the circuit board300is inserted into the first notch4114of the housing assembly410, the two side walls of the third notch310wrap around/engage with the second top surface4116, so that a distance between the light-emitting assembly and the circuit board300can be shortened. When the first laser assembly4702and the second laser assembly4802are electrically connected to the circuit board300by wire bonding, the length of the wiring between the first laser assembly4702, the second laser assembly4802and the circuit board300may be reduced.

FIG.23is a cross-sectional view of an assembly of a light-emitting assembly and a housing assembly410in an optical module according to an embodiment of the present disclosure. As shown inFIG.23, the second top surface4116is located below the light-passing holes4109of the housing assembly410, one side face (top surface) of the semiconductor refrigerator490is affixed to the second top surface4116, the first light-emitting assembly470and the second light-emitting assembly480are all affixed to the other side face (bottom surface) of the semiconductor refrigerator490. The first light-emitting assembly470and the second light-emitting assembly480use a total of eight lasers. Heat generated by the lasers is conducted to the semiconductor refrigerator490. The heat from the semiconductor refrigerator490may turn away from/bypass the light-passing holes4109, and is conducted to the upper surface of the housing assembly410from regions where no drillings are formed in the housing assembly410, and is then conducted to the casing of the optical module through thermally conductive material for heat dissipating.

In the embodiments of the present disclosure, the light-emitting assembly is disposed underneath the partition wall of the housing assembly, with the partition wall being provided above the top surface of the light-emitting cavity and jointed with the top surface of the light-emitting cavity; the light-passing holes4109are provided in the partition wall. A heat conduction for the light-emitting assembly may be realized via the partition wall, and the partition wall is the heat conduction path for the light-emitting assembly. The partition wall realizes a separation of the light-receiving cavity and the slot in the light-receiving portion and a connection thereof via the partition wall. In order to obtain a light path between the light-receiving cavity and the slot, light-passing holes are provided in the partition wall. The light beam demultiplexed and output from the wavelength division multiplexing component at the light-receiving end is transmitted to the lens assembly, and each beam output from the wavelength division multiplexing component is conducted to a corresponding collimating lens through a light-passing hole4109.

In order to facilitate a heat conduction of the light-emitting assembly, the upper and lower portions of the housing assembly410are integrated together, so that heat generated in the light-emitting end can be conducted via the housing assembly410(for example conducted to the upper surface of the housing assembly via the partition wall), and is then conducted to the casing of the optical module through thermally conductive material for heat dissipation, as shown by the arrow, which improves a heat dissipation efficiency of the light-emitting end.

At the side of the housing assembly410approximate to the optical fiber adapter are provided a third through hole4119and a fourth through hole4120which are both communicated with the light-emitting cavity4115. The third optical fiber adapter603is inserted into the light-emitting cavity4115through the third through hole4119, for receiving a convergent beam output from the first focusing lens701; the fourth optical fiber adapter604is inserted into the light-emitting cavity4115through the fourth through hole4120, for receiving the convergent beam output from the two convergent lens702.

In the embodiments of the present disclosure, the light-emitting cavity4115comprises a top plate and side plates surrounding the top plate. The top plate and the side plates form a cavity structure for holding the first light-emitting assembly470, the first wavelength division multiplexing component4601, the first converging lens701, the second light-emitting assembly480, the second wavelength division multiplexing component4602and the second converging lens702. At the bottom of the side plates of the light-emitting cavity4115is provided a third cover fixing glue groove4115a, such that the cover403may be in turn fixedly secured onto the light-emitting cavity4115by glue. In some embodiments of the present disclosure, the third cover fixing glue groove4115forms a closed-loop structure at the bottom of the side plate of the light-emitting cavity4115, thereby an adhesive area for the third cover403onto the bottom of the side plates of the light-emitting cavity4115may be increased, so that the packaging reliability of the third cover403and the bottom of the side plates of the light-emitting cavity4115may be well guaranteed. In some embodiments of the present disclosure, at the bottom of the side plates of the light-emitting cavity4115is further provided a third repairing opening4115bwhich is provided at the edge on the bottom of the side plate of the light-emitting cavity4115and is communicated with the third cover fixing glue groove4115a. When the devices inside the light-emitting cavity4115need to be repaired after the third cover403and the light-emitting cavity4115were packaged, the third cover403can be disassembled from the light-emitting cavity4115via the third repairing opening4115b, and then the third cover403can be removed without damaging the third cover403or the light-emitting cavity4115, thereby reducing the difficulty and cost of repairing.

The optical module according to the embodiment of the present disclosure utilizes an integrated metal housing assembly. The housing assembly is opened from the upper and lower surfaces for arranging the light-emitting assembly and the light-receiving assembly respectively, and the light-emitting assembly and the light-receiving assembly are placed/stacked one above the other; that is, the light-emitting assembly and the light-receiving assembly share the separation board in the middle of the housing assembly, with the light-receiving assembly being disposed on the upper side of the separation board, and the light-emitting assembly being disposed on the lower side of the separation board; one end of the circuit board is inserted into the housing assembly; high-frequency wirings of the light-emitting assembly and the light-receiving assembly are respectively routed on the upper and lower surface of the circuit board to avoid cross effects. The integrated structure of the light-emitting assembly and the light-receiving assembly can solve the problem of insufficient overall space of an optical module using discrete light-emitting assembly and the light-receiving assembly, and is beneficial for a miniaturization of the optical module.

Finally, it should be noted that the foregoing embodiments are merely intended to describe the technical solutions of the present disclosure, and shall not be construed as limitation. Although the present disclosure is described in detail with reference to the foregoing embodiments, one of ordinary skills in the art may understand that modifications still may be made to the technical solutions disclosed in the foregoing embodiments, or equivalent replacements may be made to some of the technical features. However, these modifications or equivalent replacements do not deviate the nature of corresponding technique solutions from the spirit and scope of the technique solutions of the embodiments of the present disclosure.