Optical fiber coupler and optical communication system
By using a combination of microlens arrays and beam shift prisms, the problems of complex manufacturing and large size of fiber optic couplers were solved, achieving efficient and simple fiber optic signal coupling and miniaturized design.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- FOCUSLIGHT TECH INC
- Filing Date
- 2025-10-27
- Publication Date
- 2026-05-15
AI Technical Summary
Existing fiber optic couplers are complex to manufacture, difficult to control, have low yield rates, and are bulky.
By employing a first microlens array, a beam shifting prism, and a second microlens array, the beam is collimated, separated, and focused to achieve simple coupling of the fiber optic signal, ensuring design matching between the microlens array and the fiber.
The process is simple, the yield is high, and the product size is significantly reduced.
Smart Images
Figure CN2025130079_15052026_PF_FP_ABST
Abstract
Description
Fiber optic couplers and optical communication systems Technical Field
[0001] This application relates to the field of optical communication technology, specifically to an optical fiber coupler and an optical communication system. Background Technology
[0002] Multicore fiber (MCF) technology was developed to increase data throughput. At the start of MCF signal transmission, the multicore fibers need to be coupled into manageable standard fibers so that the optical signal can be processed and connected to their respective transmitters. At the end of MCF signal transmission, the light carrying the signal in each core needs to be separated into another bundle containing standard fibers and directed to its corresponding receiver. The reverse process is also required.
[0003] Currently, fiber optic couplers are manufactured using biconical fusion splicing technology. This involves tightly bundling a bundle of optical fibers together and heating it through a controlled, slow pulling process to create an adiabatic taper. When the relative positions of the cores in the thinned fiber bundle match those in the multi-core fiber, the heating and pulling process is stopped, and the bundle is split into smooth, flat end faces. These end faces are then fused to the multi-core fiber using a fusion splicer. This process results in a highly complex and difficult-to-control fiber optic coupler manufacturing process, extremely low yield, and large size. Summary of the Invention
[0004] In view of the above problems, this application provides an optical fiber coupler and an optical communication system to solve at least one technical problem of existing optical fiber couplers, such as complex manufacturing process, difficult control, low yield, and large size.
[0005] According to one aspect of the embodiments of this application, an optical fiber coupler is provided, comprising: a first microlens array, a beam shifting prism, and a second microlens array, wherein:
[0006] The first microlens array is used to collimate the array beam incident on the first microlens array to form a first collimated array beam; the number, arrangement and optical parameters of the microlenses in the first microlens array are matched with the array beam incident on the first microlens array.
[0007] The beam shifting prism includes a light-transmitting region and a reflection shifting region that match the first collimated array beam. The first collimated array beam forms a second collimated array beam through the light-transmitting region and the reflection shifting region. The parameters of the sub-beams of the second collimated array beam do not change relative to the first collimated array beam, but the distance between the optical axes of different sub-beams is expanded or reduced.
[0008] The second microlens array is used to focus the second collimated array beam to form an output array beam. The number, arrangement, and optical parameters of the microlenses in the second microlens array are matched with the second collimated array beam. The coupling process for fiber optic signals achieved through the first microlens array, beam shift prism, and second microlens array is simple, easy to control, and has a high yield. The use of a microlens array also significantly reduces the product size.
[0009] In one alternative approach, the microlens parameters in the second microlens array are the same as those in the first microlens array. Having identical microlens parameters results in more standardized and uniform beam processing.
[0010] In one alternative approach, a portion of the sub-beams of the first collimated array beam propagates in a straight line through the light-transmitting region, while another portion of the sub-beams propagates radially through the reflection channel formed by the reflection displacement region. All the exit paths of the sub-beams are parallel to each other and parallel to the first collimated array beam, forming a second collimated array beam. By setting different regions, sub-beams at different positions are transmitted according to a preset propagation direction, achieving the purpose of separating or contracting the optical axis distance of the array beam.
[0011] According to another aspect of the embodiments of this application, an optical communication system is provided, including the aforementioned fiber optic coupler, and further including an input end and an output end. The input end is used to input an array of light beams with a preset number, arrangement, and optical parameters to the fiber optic coupler; the output end is used to receive the output array light beams of the fiber optic coupler. The input signal and output signal of the fiber optic coupler are transmitted to the optical communication system through the input end and the output end.
[0012] In one alternative approach, the input is a multi-core optical fiber, and the output is a bundle of optical fibers. This approach is suitable for applications where the input is a small-pitch beam and the output is a large-pitch beam.
[0013] In one alternative approach, the arrangement of microlenses in the first microlens array matches the arrangement of the core of the multi-core optical fiber; the light-transmitting region and the reflection-displacement region of the beam-shifting prism are set according to the multiple by which the distance between the output array beam and the optical axis of the input array beam is magnified.
[0014] In one alternative embodiment, the arrangement of the microlenses in the second microlens array is matched with the arrangement of the beam shift prism and the fiber bundle. The arrangement of the second microlens array ensures that the widely spaced beam is focused onto the output end along a predetermined path.
[0015] In one alternative approach, the input end is an optical fiber bundle, and the output end is a multi-core optical fiber. This approach is suitable for applications where the input is a large-pitch beam and the output is a small-pitch beam.
[0016] In one alternative embodiment, the microlenses in the second microlens array are configured to match the core of the optical fiber bundle; the light-transmitting region and the reflection-displacement region of the beam-shifting prism are configured according to a preset multiple by which the distance between the output beam and the optical axis of the input beam is reduced. The configuration of the second microlens array and the beam-shifting prism allows the large-pitch beam to be aligned and then contracted to obtain a preset small-pitch beam.
[0017] In one alternative embodiment, the arrangement of the microlenses in the first microlens array is matched with the arrangement of the beam shift prism and the fiber bundle. The arrangement of the first microlens array ensures that the finely spaced beam is focused onto the output end along a predetermined path.
[0018] This embodiment of the application uses a first microlens array to collimate the beam emitted by each core of the multi-core optical fiber, forming a first collimated array beam for optical signal processing. The beam displacement prism spatially separates the sub-beams of the first collimated array beam, thus expanding the distance between the optical axes of the sub-beams to form a second collimated array beam. This second collimated array beam then passes through a second microlens array and is focused into the fiber bundle by lenses on the second microlens array, completing the fiber signal coupling from the multi-core optical fiber to the fiber bundle. The coupling of the fiber signal can be achieved simply by ensuring design matching between the first microlens array and the multi-core optical fiber, and between the second microlens array and the fiber bundle. The process is simple, easy to control, and has a high yield. The use of a microlens array also significantly reduces the product size.
[0019] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description
[0020] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:
[0021] Figure 1 is a partial structural diagram of the optical communication system provided in an embodiment of this application;
[0022] Figure 2 is a schematic diagram of the multi-core optical fiber structure provided in an embodiment of this application;
[0023] Figure 3 is a partial optical path diagram of the optical communication system provided in an embodiment of this application.
[0024] The reference numerals in the detailed embodiments are as follows: 100, optical communication system; 10, multi-core optical fiber; 20, optical fiber coupler; 21, first microlens array; 22, beam shift prism; 23, second microlens array; 221, light-transmitting region; 222, reflection shift region; 30, optical fiber bundle. Detailed Implementation
[0025] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.
[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.
[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.
[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0029] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.
[0030] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).
[0031] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.
[0032] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.
[0033] Multicore fiber (MCF) technology was developed to increase data throughput. However, at the start of MCF signal transmission, the multicore fibers need to be coupled into manageable standard fibers so that the optical signals can be processed and connected to their respective transmitters. At the end of MCF signal transmission, the light carrying the signal in each core needs to be separated into another bundle of standard fibers and directed to its corresponding receiver.
[0034] The inventors of this application have noted that fiber optic couplers are manufactured using a biconical fusion splicing technique, which involves tightly bundling a bundle of optical fibers together and heating it through a controlled, slow pulling process to create an adiabatic taper. When the relative positions of the cores in the thinned fiber bundle match the relative positions of the cores in the multi-core fiber, the heating and pulling process is stopped, and the bundle is split into a smooth, flat end face. This end face is then fused to the multi-core fiber using a fusion splicer. This process results in a highly complex and difficult-to-control fiber optic coupler manufacturing process, a very low yield, and a large size.
[0035] To address the aforementioned technical problems, the inventors of this application, through research, provide a novel fiber optic coupler design for both multi-core optical fibers to fiber bundles and vice versa. The fiber optic coupler includes a first microlens array, a beam shift prism, and a second microlens array. Coupling of optical fiber signals is achieved through these components. The manufacturing process is simple, requiring only design matching between the first microlens array and the multi-core optical fiber, and between the second microlens array and the fiber bundle. This simplifies the process, makes it easy to control, and results in a high yield. Furthermore, the use of a microlens array significantly reduces the product size.
[0036] Referring to Figures 1 and 2, Figure 1 is a partial structural diagram of the optical communication system provided in the embodiment of this application; Figure 2 is a schematic diagram of the multi-core optical fiber structure provided in the embodiment of this application; and Figure 3 is a partial optical path diagram of the optical communication system provided in the embodiment of this application.
[0037] This application takes an optical communication system 100 with an optical path propagation direction from a multi-core optical fiber to an optical fiber bundle as an example, wherein the multi-core optical fiber is the input end and the optical fiber bundle is the output end.
[0038] The optical communication system 100 includes a multi-core optical fiber 10, an optical fiber coupler 20, and an optical fiber bundle 30.
[0039] The fiber optic coupler 20 includes a first microlens array 21, a beam shift prism 22, and a second microlens array 23.
[0040] In this embodiment, the multi-core optical fiber 10 is configured with 7 cores as an example. Please refer to Figure 2 for details, which shows the core arrangement of the multi-core optical fiber 10. In this arrangement, one core F2 is the central core, and the other 6 cores are evenly distributed around the central core F2. However, this application is not limited to this number and arrangement.
[0041] Referring to Figure 1, the first microlens array 21 is used to collimate the array beam incident on the first microlens array 21 to form a first collimated array beam; the number, arrangement, and optical parameters of the microlenses in the first microlens array 21 are matched with the array beam incident on the first microlens array. Referring to Figures 2 and 3, the cores F1, F2, and F3 of the multi-core optical fiber 10 are respectively configured to correspond to the microlenses L1, L2, and L3 in the first microlens array 21. In some specific applications, the optical parameters of each microlens are the same. Further, the first microlens array 21 is positioned relative to each core of the multi-core optical fiber 10 to collimate the array beam emitted from the multi-core optical fiber, forming a first collimated array beam.
[0042] The first collimated array beam enters the beam shift prism 22, which includes a light-transmitting region 221 and a reflection shifting region 222. By setting different regions, sub-beams at different positions are transmitted according to a preset propagation direction, achieving the purpose of sub-beam separation or contraction. In this embodiment, the center position of the beam shift prism 22 is set as the light-transmitting region 221. As shown in Figure 2, the collimated sub-beam emitted from the microlens L2 propagates in a straight line through the light-transmitting region 221 of the beam shift prism 22 without displacement. The reflection shifting region 222 is provided with reflection channels matching the positions of the other microlenses in the first microlens array 21. The collimated sub-beams emitted from the microlenses propagate radially through the corresponding reflection channels and move to an external position. When leaving the beam shift prism 22, the exit paths of the sub-beams are all parallel to each other and parallel to their original propagation direction before entering the beam shift prism 22, forming the second collimated array beam. For example, if the distance between the optical axes of the two input sub-beams is d1, after passing through the beam displacement prism 22, the corresponding distance between the optical axes of the two output sub-beams is d2. The light-transmitting area and the reflection displacement area of the beam displacement prism 22 are set according to a preset multiple by which the distance between the output beam and the optical axis of the input beam is expanded or reduced.
[0043] The second microlens array 23 is used to focus the second collimated array beam to form an output array beam. The number, arrangement, and optical parameters of the microlenses in the second microlens array 23 are matched with those of the second collimated array beam. The second collimated array beam, relative to the first collimated array beam, has its optical axis distance spatially increased by the beam displacement prism 22, but its beam parameters remain unchanged. After passing through the second microlens array 23, it is focused into the fiber bundle 30 by the lenses on the second microlens array 23. The positions of the lenses in the second microlens array 23 match the positions of the second collimated array beam emitted from the beam displacement prism 22, and their parameters are the same as those of the lenses in the first microlens array 21. The identical microlens parameters in the first microlens array 21 and the second microlens array 23 make the beam processing more standardized and uniform.
[0044] The fiber bundle 30 is configured such that the position of each fiber core of the fiber bundle 30 matches the position of each lens in the second microlens array 23. Referring to FIG3, three fiber cores F1', F2' and F3' of the fiber bundle 30 are matched with the positions of three microlenses L1', L2' and L3' of the second microlens array 23, and the axial position relative to the second microlens array 23 ensures that all sub-beams focused by the second microlens array 23 are focused into the fiber cores of the fiber bundle 30.
[0045] In this embodiment, a first microlens array 21 is used to collimate the sub-beams emitted by each core of the multi-core optical fiber 10, forming a first collimated array beam for optical signal processing. The first collimated array beam is spatially separated by the beam displacement prism 22 to form a second collimated array beam. The second collimated array beam then passes through a second microlens array 23 and is focused into the fiber bundle 30 by the lenses on the second microlens array 23, completing the optical fiber signal coupling from the multi-core optical fiber 10 to the fiber bundle 30. The coupling of optical fiber signals can be achieved simply by ensuring design matching between the first microlens array and the multi-core optical fiber, and between the second microlens array and the fiber bundle. The process is simple, easy to control, and has a high yield. The use of a microlens array significantly reduces the product size.
[0046] In other embodiments, based on the principle of optical path reversibility, the beam path from the fiber bundle to the multi-core fiber is the same as in the above embodiments, but in the opposite direction, and will not be described in detail here.
[0047] As can be seen, the fiber optic coupler provided in this application can realize bidirectional fiber optic coupling from multi-core fiber to fiber bundle or from fiber bundle to multi-core fiber.
[0048] The optical communication system provided in this application embodiment can be applied to fields such as data centers, optical fiber communication, artificial intelligence, quantum computing, augmented reality (AR) / virtual reality (VR).
[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. An optical fiber coupler, characterized in that, include: The first microlens array, the beam shifting prism, and the second microlens array, wherein: The first microlens array is used to collimate the array beam incident on the first microlens array to form a first collimated array beam; the number, arrangement and optical parameters of the microlenses in the first microlens array are matched with the array beam incident on the first microlens array. The beam shifting prism includes a light-transmitting region and a reflection shifting region that match the first collimated array beam. The first collimated array beam forms a second collimated array beam through the light-transmitting region and the reflection shifting region. The parameters of the sub-beams of the second collimated array beam do not change relative to the first collimated array beam, but the distance between the optical axes of different sub-beams is expanded or reduced. The second microlens array is used to focus the second collimated array beam to form an output array beam, and the number, arrangement and optical parameters of the microlenses in the second microlens array are matched with the second collimated array beam.
2. The fiber optic coupler according to claim 1, characterized in that, The microlens parameters in the second microlens array are the same as those in the first microlens array.
3. The fiber optic coupler according to claim 1, characterized in that, A portion of the sub-beams of the first collimated array beam propagates in a straight line through the light-transmitting region, while another portion of the sub-beams propagates radially through the reflection channel formed by the reflection displacement region. The paths of all the sub-beams are parallel to each other and parallel to the first collimated array beam, forming a second collimated array beam.
4. An optical communication system, characterized in that, The fiber optic coupler as described in any one of claims 1 to 3 further includes an input end and an output end, wherein the input end is used to input an array of beams of a preset number, arrangement and optical parameters to the fiber optic coupler; and the output end is used to receive the output array beams of the fiber optic coupler.
5. The optical communication system according to claim 4, characterized in that, The input end is a multi-core optical fiber, and the output end is an optical fiber bundle.
6. The optical communication system according to claim 4 or 5, characterized in that, The microlenses in the first microlens array are configured to match the core of the multi-core optical fiber; the light-transmitting region and the reflection-displacement region of the beam displacement prism are configured according to the multiple by which the distance between the output array beam and the optical axis of the input array beam is magnified.
7. The optical communication system according to claim 4 or 5, characterized in that, The arrangement of the microlenses in the second microlens array is matched with the arrangement of the beam displacement prism and the fiber bundle.
8. The optical communication system according to claim 4, characterized in that, The input end is an optical fiber bundle, and the output end is a multi-core optical fiber.
9. The optical communication system according to claim 4 or 8, characterized in that, The microlenses in the second microlens array are configured to match the core of the optical fiber bundle; the light-transmitting region and the reflection-displacement region of the beam displacement prism are configured according to a preset multiple by which the distance between the output beam and the optical axis of the input beam is reduced.
10. The optical communication system according to claim 4 or 8, characterized in that, The arrangement of the microlenses in the first microlens array is matched with the arrangement of the beam displacement prism and the fiber bundle.