Optical module

Abstract

An optical module, comprising an optical mirror (40), a support block (50), a photodetector (30), and a transimpedance amplifier (20) electrically connected to the photodetector (30). The support block (50) is fixedly arranged on the transimpedance amplifier (20); the optical mirror (40) is fixedly arranged on the support block (50) and extends to a light incident path of the photodetector (30); the optical mirror (40) comprises a coupling lens (41) located on the light incident path of the photodetector (30); the coupling lens (41) is used for coupling an optical signal to the photodetector (30); and the photodetector (30) is used for converting the received optical signal into an electrical signal and transmitting the electrical signal to the transimpedance amplifier (20). The support block (50) for fixing the optical mirror (40) is fixed on the transimpedance amplifier (20), and the support block (50) and the transimpedance amplifier (20) are stacked instead of being arranged side by side, so that the occupied area can be greatly reduced, and miniaturization of optical module products is facilitated.

Description

optical modules

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 9, 2023, with application number 202322138699.5 and invention name “Optical Module”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The utility model relates to the technical field of optical modules, in particular to an optical module. Background Art

[0003] In recent years, the development of emerging technologies such as data centers, high-performance computing, and 5G communications has placed higher demands on information transmission speeds. Consequently, the market is placing increasing demands on optical transceiver modules, a key component of communication systems. (With the rapid development of optical communications and the internet in recent years, user demand for networks has also surged, leading to a 50% to 80% annual increase in traffic on telecommunications backbone networks.) To adapt to the rapid development of the network market, the transmission speed of optical modules is also increasing rapidly, from traditional single-channel 25G optical modules to 100G optical modules, and even in the future, single-channel 200G or higher optical modules will appear.

[0004] This speed increase not only requires higher bandwidth, but also has higher requirements for module integration. The miniaturization problem has also become a huge challenge in the industry.

[0005] For an optical module with a light receiving function, it usually includes a transimpedance amplifier, a light detector, and an optical mirror. The light signal received from the outside is transmitted to the light detector through the optical mirror, and is converted into an electrical signal by the light detector. The electrical signal is then transmitted to the circuit board via the transimpedance amplifier. The common assembly scheme of this type of optical module is: a support block is arranged side by side with the transimpedance amplifier, and the optical mirror is fixedly mounted on the support block and extends above the light detector so as to adapt to the light incident surface of the light detector. However, such an assembly scheme occupies a large area and is not conducive to the miniaturization of the product. Summary of the Invention

[0006] In order to solve the above technical problems, the purpose of the present utility model is to provide an optical module.

[0007] To achieve the above-mentioned purpose, one embodiment provides an optical module, which includes an optical mirror, a support block, a light detector and a transimpedance amplifier electrically connected to the light detector, the support block is fixed to the transimpedance amplifier, the optical mirror is fixed to the support block and extends to the light incident path of the light detector, the optical mirror includes a coupling lens located on the light incident path of the light detector, the coupling lens is used to couple the incident light to the light detector, and the light detector is used to convert the received incident light into an electrical signal and transmit it to the transimpedance amplifier.

[0008] As a further improvement of one embodiment, the transimpedance amplifier has a first surface and a second surface arranged opposite to each other, the support block is fixed to the first surface of the transimpedance amplifier; the light incident surface of the photodetector is arranged in the same direction as the first surface of the transimpedance amplifier.

[0009] As a further improvement of one embodiment, the support block is fixed to the first surface of the transimpedance amplifier, and the optical mirror is fixed to a side of the support block facing away from the transimpedance amplifier.

[0010] As a further improvement of an embodiment, the photodetector is fixed to the first surface of the transimpedance amplifier.

[0011] As a further improvement of one embodiment, the first surface of the transimpedance amplifier is provided with an electrode for flip-chip bonding, the photodetector is fixed on the electrode of the transimpedance amplifier by flip-chip bonding, and is electrically connected to the transimpedance amplifier through the electrode.

[0012] As a further improvement of an embodiment, the photodetector is configured as a PN photodiode, a PIN photodiode, an avalanche photodiode, or a single-photon avalanche photodiode.

[0013] As a further improvement of one embodiment, the optical mirror further includes a light path deflector having a reflective mirror surface, and the light path deflector is used to reflect the incident light onto the coupling lens.

[0014] As a further improvement of one embodiment, the optical path deflector is fixed on the supporting block, the reflecting mirror is suspended on the light incident path of the light detector, and the coupling lens is fixed on the exit surface of the optical path deflector. After the incident light is reflected by the reflecting mirror, it is emitted to the coupling lens through the exit surface of the optical path deflector.

[0015] As a further improvement of one embodiment, the optical module also includes a shell having an optical port, and any one or more of an optical fiber, an optical fiber jack, an optical attenuation element, an optical enhancement element, a collimating lens, a periscope, a wavelength division multiplexer, a focusing lens, and a coupling lens located in the light propagation path between the optical port and the optical mirror.

[0016] As a further improvement of one embodiment, the optical mirror has a fixed area and a suspended area that are connected to each other, the fixed area is fixed on the support block, the suspended area extends laterally out of the support block and is suspended on the light incident path of the light detector, and the coupling lens is located in the suspended area.

[0017] As a further improvement of an embodiment, the optical module further includes a circuit board, and the transimpedance amplifier is electrically connected to the circuit board.

[0018] As a further improvement of one embodiment, the circuit board is configured as any one of a rigid circuit board, a flexible circuit board, and a rigid-flexible board.

[0019] As a further improvement of one embodiment, the transimpedance amplifier is electrically connected to the circuit board via bonding wires, or the transimpedance amplifier is fixedly mounted on the surface of the circuit board by flip-chip bonding and electrically connected to the circuit board.

[0020] As a further improvement of one embodiment, the optical module includes two or more light detectors arranged side by side, the distance between any two light detectors and the support block is equal, and the support block and the two or more light detectors arranged side by side are arranged side by side in a direction away from the light port; the optical mirror includes two or more coupling lenses corresponding one-to-one to the two or more light detectors, and each coupling lens is located on the light incident path of the corresponding light detector.

[0021] Compared with the prior art, the beneficial effect of the present invention is that by fixing the support block for fixing the optical mirror on the transimpedance amplifier, the support block and the transimpedance amplifier are stacked instead of side by side, which can greatly reduce the occupied area, facilitate the miniaturization of optical module products, and improve the integration of optical modules, and is particularly suitable for ultra-high bandwidth applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is an exploded schematic diagram of a partial structure of an optical module according to an embodiment of the present invention;

[0023] FIG2 is another exploded schematic diagram of a partial structure of an optical module according to an embodiment of the present invention, and its schematic angle is different from that of FIG1 ;

[0024] FIG3 is a schematic diagram of a portion of the light propagation path of an optical module according to an embodiment of the present invention;

[0025] FIG4 is a schematic diagram of a partial structure of an optical module according to an embodiment of the present invention, wherein an enlarged view of area A is also shown. DETAILED DESCRIPTION

[0026] The present application will be described in detail below with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present application, and any structural, methodological, or functional changes made by a person skilled in the art based on these embodiments are included within the scope of protection of the present application.

[0027] In the various drawings of the present application, for the sake of convenience, some sizes of structures or parts are exaggerated relative to other structures or parts. Therefore, they are only used to illustrate the basic structure of the subject matter of the present application.

[0028] 1 to 4 , this embodiment provides an optical module.

[0029] The optical module has at least a light receiving function. Specifically, referring to FIG1 , it includes a housing having an optical port, and includes a light detector 30, an optical mirror 40, and a transimpedance amplifier 20 housed in the housing. The optical mirror 40 is located on the light incident path of the light detector 30. Specifically, as shown in FIG2 , the optical mirror 40 includes a coupling lens 41; the light detector 30 is electrically connected to the transimpedance amplifier 20. The optical module receives incident light from the outside through the optical port. The light signal is coupled to the light detector 30 through the coupling lens 41. The light detector 30 converts the received light signal into an electrical signal. Thereafter, the light detector 30 transmits the electrical signal to the transimpedance amplifier 20.

[0030] The optical module also includes a support block 50 for fixing and supporting the optical mirror 40. In the present application, the support block 50 is fixed to the transimpedance amplifier 20, and the optical mirror 40 is fixed to the support block 50 and extends to the light incident path of the photodetector 30, so that the coupling lens 41 is located on the light incident path of the photodetector 30. In this way, compared with the common solution of arranging the support block and the transimpedance amplifier side by side as mentioned in the background art, the present application fixes the support block 50 for fixing the optical mirror 40 on the transimpedance amplifier 20, that is, the support block 50 and the transimpedance amplifier 20 are stacked rather than side by side, and the other end of the optical mirror 40 is suspended. Only one end of the optical mirror 40 needs to be provided with the support block 50, which can greatly reduce the occupied area, facilitate the miniaturization of the optical module product, and facilitate the improvement of the integration of the optical module, thereby helping to further improve the optical module speed within the standard optical module size and realize an ultra-high-speed optical module.

[0031] As mentioned above, the coupling lens 41 is used to couple the optical signal to the light detector 30. More specifically, the coupling lens 41 can be arranged directly opposite the light incident surface 31 of the light detector 30, and its focus can be located on or near the light incident surface 31 of the light detector 30 (for example, slightly offset from the light incident surface 31) so that the light spot of the incident light falls as completely as possible into the light incident surface 31 of the light detector 30.

[0032] 1 and 2 , the transimpedance amplifier 20 has a first surface 21 and a second surface 22 opposite to each other, and the support block 50 is fixed to the first surface 21 . The light incident surface 31 of the photodetector 30 is arranged in the same direction as the first surface 21 of the transimpedance amplifier 20 .

[0033] For example, if this application defines the orientation “up” by the position of the first surface 21 of the transimpedance amplifier 20 relative to the second surface 22, and defines the orientation “down” by the position of the second surface 22 relative to the first surface 21, then the first surface 21 can be regarded as the upper surface of the transimpedance amplifier 20, and the second surface 22 can be regarded as the lower surface of the transimpedance amplifier 20.

[0034] The light incident surface 31 of the photodetector 30 and the first surface 21 of the transimpedance amplifier 20 are arranged in the same direction, that is, they are both arranged upward. Accordingly, the coupling lens 41 is located directly above the light incident surface 31 of the photodetector 30 .

[0035] It should be noted that the descriptions of the directions "up" and "down" in this application are based on the relative positions of the first surface 21 and the second surface 22 of the transimpedance amplifier 20. These are relative concepts adopted for clarity and ease of understanding. These directions "up" and "down" are not consistent with the gravitational concepts of "up" and "down." For example, the module or component can be oriented in other ways (rotated 90 degrees or in other directions) so that the first surface 21 and the second surface 22 of the transimpedance amplifier 20 are opposite to each other in the gravitational concept.

[0036] 2 , the optical lens 40 has a fixed area 401 and a suspended area 402. The fixed area 401 is fixed to the support block 50, that is, the fixed area 401 overlaps directly above the support block 50; the suspended area 402 extends laterally from the support block 50 and is suspended, that is, there is no support block 50 directly below the suspended area 402, and the coupling lens 41 is located in the suspended area 402.

[0037] Furthermore, the lower surface of the support block 50 is fixed to the first surface 21 of the transimpedance amplifier 20 by adhesive, and the optical mirror 40 is fixed to the upper surface of the support block 50, that is, the side of the support block 50 facing away from the transimpedance amplifier 20, by adhesive. With this mounting and fixing method, the optical mirror 40, the support block 50, and the transimpedance amplifier 20 are stacked one on top of the other, resulting in a more compact structure and simple and convenient installation.

[0038] In addition, in this embodiment, referring to Figure 3, the light detector 30 adopts a surface receiving type device, and the light receiving direction of its light incident surface 31 is perpendicular to the main axis of the light propagation path in the optical module. Correspondingly, the optical module also includes an optical path deflector 60 having a reflective mirror 61. In this way, on the light propagation path of the optical module, after the light signal with the main axis perpendicular to the up and down directions enters the light path deflector 60, it is reflected at the reflective mirror 61 and converted into a light signal with the main axis parallel to the up and down directions (or the main axis perpendicular to the light incident surface 31 of the light detector 30), and then coupled to the light detector 30 by the coupling lens 41.

[0039] The above describes the example of the optical mirror 40 including the coupling lens 41 in the accompanying drawings, which is fixed on the support block 50, and the optical path deflector 60 and the coupling lens 41 are separately arranged; of course, in a variant embodiment, for example, the optical mirror can also include an integrated structure composed of an optical path deflector with a reflective mirror surface (for example, the optical path deflector 60 in the accompanying drawings) and a coupling lens (for example, the coupling lens 41 in the accompanying drawings) whose focus is located at the light incident surface 31 of the light detector 30 (for example, the coupling lens 41 in the accompanying drawings is directly fixed on the optical path deflector 60), and the integrated structure is fixed on the support block 50 (for example, the optical path deflector 60 in the accompanying drawings is fixed on the support block 50, and at the same time, the reflective mirror surface 61 of the optical path deflector 60 is suspended on the light incident path of the light detector 30, and the coupling lens 41 is fixed on the exit surface of the optical path deflector 61, and the light signal is reflected by the reflective mirror surface 61 and then emitted to the coupling lens 61 through the exit surface of the optical path deflector 60). The above-mentioned variations in the implementation of the optical mirror 40 do not deviate from the technical purpose of the present application.

[0040] Furthermore, the optical module also includes any one or more of an optical fiber, an optical fiber jack, an optical attenuation element, an optical enhancement element, a collimating lens, a periscope, a wavelength division multiplexer, a focusing lens, and a coupling lens located in the light propagation path between the optical port and the optical mirror.

[0041] Referring to Figures 1 and 2 , the optical module includes two or more photodetectors 30 arranged side by side, with the spacing between any two photodetectors 30 and a support block 50 being equal. The figure illustrates four photodetectors 30 arranged side by side on one side of the support block 50. An optical mirror 40 extends into the light incident path of each photodetector 30, and the optical mirror 40 corresponds to two or more coupling lenses 41 in a one-to-one relationship with the two or more photodetectors 30. Each coupling lens 41 is located in the light incident path of a corresponding photodetector 30. In this way, multiple coupling lenses 41 of the optical mirror 40 supported by the same support block 50 simultaneously match at least two or more photodetectors 30, further reducing the complexity of the assembly process, saving assembly area, and facilitating the miniaturization and high-speed operation of the optical module.

[0042] Preferably, the direction from the optical port to the optical detector 30 defines the transmission direction of the incident light of the optical module, and the support block 50 and each optical detector 30 are arranged side by side along the transmission direction of the incident light of the optical module. That is, the support block 50 and each optical detector 30 are arranged side by side in a direction away from the optical port. For example, the support block 50 is located between each optical detector 30 and the optical port, or for example, each optical detector 30 is located between the support block 50 and the optical port (as shown in the figure).

[0043] Each optical detector 30 corresponds to a receiving-end channel of the optical module. In the accompanying drawings, the optical module is configured as an optical module with four receiving-end channels. Of course, the number of optical detectors 30 can also be one, two, or eight, and the optical module can be configured as a single-channel receiving-end optical module, a dual-channel optical module, or an eight-channel optical module, respectively.

[0044] Furthermore, in this embodiment, the photodetector 30 is fixed to the first surface 21 of the transimpedance amplifier 20, that is, the photodetector 30 and the support block 50 are mounted on the same surface of the transimpedance amplifier 20. This can further reduce the occupied area, facilitating the miniaturization of the optical module, and effectively reduce the inductance between the photodetector 30 and the transimpedance amplifier 20, thereby increasing the bandwidth of the entire package link and enhancing the anti-interference capability of the optical module.

[0045] The photodetector 30 can be fixed to the electrodes of the transimpedance amplifier 20 via flip-chip bonding. Specifically, electrodes for flip-chip bonding are provided on the first surface 21 of the transimpedance amplifier 20. The photodetector 30 can be electrically connected to the electrodes of the transimpedance amplifier 20 via a flip-chip bonding structure using solder and copper pillars, and fixed via flip-chip bonding. This significantly reduces inductance, optimizes the impedance of the high-frequency link, and facilitates increased bandwidth / rate.

[0046] Furthermore, the photodetector 30 can be configured as a PN photodiode, a PIN photodiode, an avalanche photodiode, or a single-photon avalanche photodiode. Alternatively, the photodetector 30 can be a waveguide diode or a silicon photodiode. Furthermore, the photodetector 30 can be a single diode or an integrated diode. The specific selection of the photodetector 30 is applicable according to known techniques in the art.

[0047] Furthermore, referring to FIG4 , the optical module further includes a circuit board 10 housed in the housing, and the transimpedance amplifier 20 is electrically connected to the circuit board 10. Preferably, in this embodiment, the transimpedance amplifier 20 is fixedly mounted on the surface of the circuit board 10, for example, fixed on the surface of the circuit board 10 by flip-chip soldering and electrically connected to the circuit board 10. Thus, in this case, the present application fixes the support block 50 on the transimpedance amplifier 20, or fixes the light detector 30 on the transimpedance amplifier 20, instead of arranging the support block 50 or the light detector 30 side by side with the transimpedance amplifier 20 as in the conventional technology. In addition to the aforementioned beneficial effects of greatly reducing the occupied area and facilitating product miniaturization, the surface space layout of the circuit board 10 can also be saved, the wiring compactness of the circuit board 10 can be improved, and the possibility of product miniaturization can be further improved, which helps to improve the integration of the optical module, thereby facilitating the realization of an ultra-high-speed optical module.

[0048] In addition to the flip-chip connection method, the transimpedance amplifier 20 can also be electrically connected to the circuit board 10 via bonding wires. When the transimpedance amplifier 20 receives an electrical signal from the photodetector 30, the transimpedance amplifier 20 amplifies the electrical signal and transmits it to the circuit board 10.

[0049] Among them, the bonding wires mentioned in this application can be set as metal conductive wires such as gold wires, silver wires, and copper wires.

[0050] Furthermore, the circuit board 10 can be specifically configured as the circuit board 30 which can be a flexible circuit board, a rigid circuit board, or a rigid-flexible board in which multiple layers of rigid circuit boards and flexible circuit boards are pressed into one.

[0051] As described above, the optical module of the present application has at least a light receiving function. It is known that, in one embodiment, the optical module may be an optical receiver having only a light receiving function; in another embodiment, the optical module may also be an optical transceiver having both a light receiving function and a light transmitting function. In this case, the optical module also includes an optical transmitter electrically connected to the circuit board 10, and the optical transmitter is used to receive an electrical signal from the circuit board 10 and convert the electrical signal into an optical signal, which is transmitted by the optical module to an external device. The optical transmitter may be a laser diode, such as an edge-emitting laser diode, a Fabry-Perot (FP) laser, a vertical cavity surface emitting laser (VCSEL), a distributed feedback (DFB) laser, or other suitable light sources.

[0052] To sum up, the beneficial effect of the present invention is at least that: by fixing the support block 50 for fixing the optical mirror 40 on the transimpedance amplifier 20, that is, the support block 50 and the transimpedance amplifier 20 are stacked instead of side by side, the occupied area can be greatly reduced, which is conducive to the miniaturization of the optical module product.

[0053] It should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation method can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0054] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the utility model and are not intended to limit the scope of protection of the utility model. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the utility model should be included in the scope of protection of the utility model.

Claims

1. An optical module, comprising an optical mirror, a support block, a photodetector and a transimpedance amplifier electrically connected to the photodetector, characterized in that: The support block is fixed to the transimpedance amplifier, the optical mirror is fixed to the support block and extends to the light incident path of the photodetector, the optical mirror includes a coupling lens located on the light incident path of the photodetector, the coupling lens is used to couple the incident light to the photodetector, and the photodetector is used to convert the received incident light into an electrical signal and transmit it to the transimpedance amplifier.

2. The optical module according to claim 1, characterized in that: The transimpedance amplifier has a first surface and a second surface arranged opposite to each other, the support block is fixed on the first surface of the transimpedance amplifier; the light incident surface of the photodetector is arranged in the same direction as the first surface of the transimpedance amplifier.

3. The optical module according to claim 2, characterized in that: The support block is fixed on the first surface of the transimpedance amplifier, and the optical mirror is fixed on a side of the support block facing away from the transimpedance amplifier.

4. The optical module according to claim 2, characterized in that: The photodetector is fixed on the first surface of the transimpedance amplifier.

5. The optical module according to claim 4, characterized in that: An electrode for flip-chip bonding is provided on the first surface of the transimpedance amplifier, and the photodetector is fixed on the electrode of the transimpedance amplifier by flip-chip bonding, and is electrically connected to the transimpedance amplifier through the electrode.

6. The optical module according to claim 1, characterized in that: The photodetector is configured as a PN photodiode, a PIN photodiode, an avalanche photodiode or a single-photon avalanche photodiode.

7. The optical module according to claim 1, characterized in that: The optical mirror also includes an optical path deflector having a reflective mirror surface, and the optical path deflector is used to reflect the incident light onto the coupling lens.

8. The optical module according to claim 7, characterized in that: The optical path deflector is fixed on the supporting block, the reflecting mirror is suspended on the light incident path of the light detector, the coupling lens is fixed on the exit surface of the optical path deflector, and the incident light is reflected by the reflecting mirror and then emitted to the coupling lens through the exit surface of the optical path deflector.

9. The optical module according to claim 1, characterized in that: The optical module also includes a shell having an optical port, and any one or more of an optical fiber, an optical fiber jack, an optical attenuation element, an optical enhancement element, a collimating lens, a periscope, a wavelength division multiplexer, a focusing lens, and a coupling lens located in the light propagation path between the optical port and the optical mirror.

10. The optical module according to claim 1, characterized in that: The optical mirror has a connected fixed area and a suspended area, the fixed area is fixed on the support block, the suspended area extends laterally out of the support block and is suspended on the light incident path of the photodetector, and the coupling lens is located in the suspended area.

11. The optical module according to claim 1, characterized in that: The optical module further includes a circuit board, and the transimpedance amplifier is electrically connected to the circuit board via bonding wires, or the transimpedance amplifier is fixedly mounted on the surface of the circuit board by flip-chip bonding and electrically connected to the circuit board.

12. The optical module according to claim 1, characterized in that: The optical module includes an optical port for receiving incident light from the outside and two or more optical detectors arranged side by side, the spacing between any two optical detectors and the supporting block is equal, and the supporting block and the two or more optical detectors arranged side by side are arranged side by side in a direction away from the optical port; the optical mirror includes two or more coupling lenses corresponding to the two or more optical detectors one by one, and each coupling lens is located on the light incident path of the corresponding optical detector.

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