Fiber core power coupler and fixed optical add-drop multiplexer

Abstract

A fiber core power coupler (100) and a fixed optical add-drop multiplexer (700). The fiber core power coupler (100) comprises: a connector (1), wherein a first end of the connector (1) is provided with N first fiber core interfaces (11) and M second fiber core interfaces (12), the first end of the connector (1) is used for connecting a first optical fiber (10), the first optical fiber (10) is provided with N+M fiber cores, each fiber core is correspondingly connected to one first fiber core interface (11) or one second fiber core interface (12), N≥1, and M≥0; and a coupling portion (2), which is internally provided with N single-mode optical fibers (21), wherein each single-mode optical fiber (21) is separately coupled with one first fiber core interface (11), and the coupling portion (2) is used for coupling a signal of a fiber core connected to the first fiber core interface (11) into the corresponding single-mode optical fiber (21), or coupling a signal of the single-mode optical fiber (21) into the fiber core connected to the first fiber core interface (11). The fiber core power coupler (100) and the fixed optical add-drop multiplexer (700) can realize fiber core-specific add-drop with extremely low link loss in a multi-core optical fiber system.

Description

Fiber core power couplers and fixed optical add / drop multiplexers

[0001] Cross-references

[0002] The present disclosure claims priority to Chinese patent application number 2024100577830, filed on January 15, 2024, entitled “Fiber Core Power Coupler and Fixed Optical Add / Drop Multiplexer,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the technical field of optical fiber communications, and in particular to a fiber core power coupler and a fixed optical add-drop multiplexer using the fiber core power coupler. Background Art

[0004] In a FOADM (Fixed Optical Add-Drop Multiplexer) network, corresponding TFF (Thin Film Filter) devices are required to implement add / drop (i.e., download and upload) of different services. Furthermore, not all services carried by fiber cores in a network need to be added / dropped (i.e., download and upload). To minimize link loss on other fiber cores, adding / dropping specific cores in a multi-core fiber system is necessary.

[0005] The existing method is to use a fan-in fan-out device to split the cores of a multi-core optical fiber into multiple single-mode optical fibers, connect the optical fiber of one of the cores to the TFF device, and then all the cores need to be connected to another fan-in fan-out device through single-mode LC connectors to finally achieve the wave addition and subtraction operation of specific cores in the multi-core optical fiber.

[0006] This method requires the addition of two additional fan-in and fan-out components, which increases the overall link loss, especially in the fiber cores that do not require add / drop operations, and thus increases overall cost. Therefore, a method is needed to enable add / drop operations on a single fiber core or on a few fiber cores in a multi-core fiber system without increasing link loss.

[0007] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the Invention

[0008] The purpose of the present disclosure is to provide a fiber core power coupler and a fixed optical add / drop multiplexer using the fiber core power coupler, which are used to implement specific fiber core addition and drop in a multi-core optical fiber system without increasing link loss.

[0009] According to a first aspect of the present disclosure, a fiber core power coupler is provided, comprising: a connector, wherein a first end of the connector has N first fiber core interfaces and M second fiber core interfaces, the first end of the connector being used to connect to a first optical fiber, the first optical fiber having N+M fiber cores, each fiber core correspondingly connected to one first fiber core interface or one second fiber core interface, where N ≥ 1 and M ≥ 0;

[0010] The coupling part is provided with N single-mode optical fibers inside, each of which is coupled to a first fiber core interface. The coupling part is used to couple the signal of the fiber core connected to the first fiber core interface into the single-mode optical fiber, or to couple the signal of the single-mode optical fiber into the fiber core connected to the first fiber core interface.

[0011] In an exemplary embodiment of the present disclosure, the second end of the connector has M third fiber core interfaces correspondingly connected to the M second fiber core interfaces. The second end of the connector is used to connect the second optical fiber. The second optical fiber has M fiber cores, and each fiber core of the second optical fiber is correspondingly connected to a third fiber core interface.

[0012] In an exemplary embodiment of the present disclosure, the second end of the connector has N+M third fiber core interfaces correspondingly connected to the N first fiber core interfaces and the M second fiber core interfaces. The second end of the connector is used to connect the second optical fiber, the second optical fiber has N+M fiber cores, and each fiber core of the second optical fiber is correspondingly connected to a third fiber core interface.

[0013] In an exemplary embodiment of the present disclosure, the coupling portion has one or more first single fiber core signal connection ends, the first single fiber core signal connection end and the second end of the connector are arranged in the same direction, the first single fiber core signal connection end is used to connect to the core of the third optical fiber, and the third optical fiber is used to perform signal wave removal on the core connected to the first fiber core interface.

[0014] In an exemplary embodiment of the present disclosure, the coupling portion has one or more second single fiber core signal connection ends, the second single fiber core signal connection ends are arranged in the same direction as the first end of the connector, the second single fiber core signal connection ends are used to connect to the core of a fourth optical fiber, and the fourth optical fiber is used to carry out signal wavecasting on the core connected to the first fiber core interface.

[0015] In an exemplary embodiment of the present disclosure, the distance between the coupling portion and any first fiber core interface is smaller than the distance between the coupling portion and any second fiber core interface.

[0016] In an exemplary embodiment of the present disclosure, it is manufactured in the following manner:

[0017] A single fiber core provided in a first fiber core interface and a single-mode optical fiber are placed on the flame head for taper drawing;

[0018] The temperature of the flame head and the speed of the taper are controlled to control the proximity distance between the single fiber core and the single-mode optical fiber, thereby adjusting the taper length until the single fiber core and the single-mode optical fiber reach the set coupling ratio.

[0019] In an exemplary embodiment of the present disclosure, it is manufactured in the following manner:

[0020] Place a single fiber core provided in a first fiber core interface and a single-mode optical fiber on a first base and a second base respectively, and polish the side surfaces of the single fiber core and the single-mode optical fiber respectively;

[0021] Adjust the polishing depth, polishing length, and the proximity distance between the single fiber core and the single-mode fiber until the single fiber core and the single-mode fiber reach the set coupling ratio;

[0022] A refractive index matching liquid is used to bond the single fiber core and the single-mode optical fiber, and ultraviolet glue is used to solidify the first base and the second base.

[0023] According to a second aspect of the present disclosure, there is provided a fixed optical add / drop multiplexer, comprising:

[0024] A first connection end is used to connect a first optical fiber, where the first optical fiber has N+M fiber cores, where N≥1 and M≥0;

[0025] A first fiber core power coupler, as described above, is connected to the first connection end to connect to the first optical fiber, and the first fiber core power coupler has N first fiber core interfaces and M second fiber core interfaces;

[0026] The second connection end is used to connect to a fifth optical fiber, where the fifth optical fiber has P+M fiber cores, where P≥1;

[0027] A second fiber core power coupler, as described above, connected to the second connection end to connect to the fifth optical fiber, the second fiber core power coupler having P first fiber core interfaces and M second fiber core interfaces;

[0028] One or more thin film filters, wherein the thin film filters are used to connect the coupling portion of the first fiber core power coupler through the third optical fiber, and are used to connect the coupling portion of the second fiber core power coupler through the fourth optical fiber. The thin film filters are used to perform at least one of the following functions: filtering and passing through the signal from the third optical fiber, performing signal addition to the third optical fiber, filtering and passing through the signal from the fourth optical fiber, and performing signal addition to the fourth optical fiber.

[0029] In an exemplary embodiment of the present disclosure, the fixed optical add / drop multiplexer further includes a second optical fiber connected between the first fiber core power coupler and the second fiber core power coupler.

[0030] In an exemplary embodiment of the present disclosure, the first optical fiber is used to input a signal, the thin film filter has a signal output end, the thin film filter is connected to the third optical fiber, and the thin film filter is used to filter the signal from the third optical fiber to output the first signal through the signal output end.

[0031] In an exemplary embodiment of the present disclosure, the thin film filter is also connected to a fourth optical fiber, and the thin film filter is used to filter the signal from the third optical fiber to output the first signal through the signal output end, retain the second signal, and transmit the second signal to the second fiber core power coupler through the fourth optical fiber.

[0032] In an exemplary embodiment of the present disclosure, the first optical fiber is used to input a signal, the fifth optical fiber is used to output a signal, the thin film filter is connected to the fourth optical fiber, the thin film filter has a signal input end, the thin film filter receives a third signal through the signal input end, and transmits the third signal to the second fiber core power coupler through the fourth optical fiber.

[0033] The core power coupler provided in the disclosed embodiments can extract signals from specific cores in a multi-core optical fiber (signal dropout) or add signals to specific cores in a multi-core optical fiber (signal add-in) without increasing link loss. A FOADM device using this core power coupler can add or drop signals to specific cores in a multi-core optical fiber with extremely low link loss and cost.

[0034] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0036] FIG1 is a schematic structural diagram of a fiber core power coupler in an exemplary embodiment of the present disclosure.

[0037] 2A to 2D are cross-sectional schematic diagrams of a fiber core power coupler according to an embodiment of the present disclosure.

[0038] 3A and 3B are output schematic diagrams of a fiber core power coupler according to an embodiment of the present disclosure.

[0039] 4A to 4C are schematic diagrams of ports of a coupling portion in an embodiment of the present disclosure.

[0040] FIG5 is a schematic diagram of manufacturing a fiber core power coupler according to an embodiment of the present disclosure.

[0041] FIG6 is a schematic diagram of manufacturing a fiber core power coupler according to another embodiment of the present disclosure.

[0042] 7A to 7C are schematic diagrams of a fixed optical add / drop multiplexer in an exemplary embodiment of the present disclosure.

[0043] 8A to 8C are schematic diagrams of a fixed optical add / drop multiplexer 700 completing signal addition and drop according to an embodiment of the present disclosure.

[0044] 9A to 9C are schematic diagrams of a fixed optical add / drop multiplexer 700 completing signal addition and drop according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0045] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present disclosure will be more comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced while omitting one or more of the specific details, or that other methods, components, devices, steps, etc. may be employed. In other cases, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0046] The accompanying drawings are merely schematic illustrations of the present disclosure. Identical reference numerals in the drawings denote identical or similar components, and thus their repeated descriptions will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities that do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0047] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0048] FIG1 is a schematic structural diagram of a fiber core power coupler in an exemplary embodiment of the present disclosure.

[0049] 1 , a core power coupler 100 may include:

[0050] Connector 1, wherein the first end of connector 1 has N first fiber core interfaces 11 and M second fiber core interfaces 12. The first end of connector 1 is used to connect to a first optical fiber 10. The first optical fiber 10 has N+M fiber cores, each fiber core corresponding to one first fiber core interface 11 or one second fiber core interface 12, where N ≥ 1 and M ≥ 0.

[0051] The coupling part 2 is provided with N single-mode optical fibers 21 inside, and each single-mode optical fiber 21 is coupled to a first fiber core interface 11 respectively. The coupling part 2 is used to couple the signal of the fiber core connected to the first fiber core interface 11 to the single-mode optical fiber 21, or to couple the signal of the single-mode optical fiber 21 to the fiber core connected to the first fiber core interface 11.

[0052] The first optical fiber 10 is a multi-core optical fiber having N+M cores.

[0053] The first fiber core interface 11 and the second fiber core interface 12 are structurally identical, differing only in function and position. FIG1 shows the first fiber core interface 11 and the second fiber core interface 12 as being relatively far apart for illustrative purposes. The actual positional relationship between the two can be seen in FIG2 .

[0054] A single fiber core is provided in each of the first fiber core interface 11 and the second fiber core interface 12 to connect the signal transmission path of each fiber core in the first optical fiber 10. In some embodiments, a fiber core positioning device may also be provided in the first fiber core interface 11 and the second fiber core interface 12 to ensure that when the fiber core in the first optical fiber 10 is connected to the first fiber core interface 11 or the second fiber core interface 12, it can be accurately connected to the single fiber core inside the first fiber core interface 11 or the second fiber core interface 12. In addition, when the first optical fiber 10 is connected to the first end of the connector 1, each fiber core in the first optical fiber 10 can first be flattened to ensure that each fiber core in the first optical fiber 10 can be accurately connected to the single fiber core inside the first fiber core interface 11 or the second fiber core interface 12.

[0055] In some embodiments, N=1, and the fiber core power coupler 100 can be used to implement signal uploading (wave loading) and signal downloading (wave dropping) of a single fiber core. In other embodiments, N>1, and the fiber core power coupler 100 can be used to implement signal uploading (wave loading) and signal downloading (wave dropping) of multiple specific fiber cores.

[0056] Because the first fiber core interface 11 and the second fiber core interface 12 are configured identically, when connecting the first optical fiber 10, any N fiber cores can be connected to the first fiber core interface 11, and the remaining M fiber cores can be connected to the second fiber core interface 12. Furthermore, specific N fiber cores can be connected to the first fiber core interface 11, and those skilled in the art can configure the configuration based on actual needs.

[0057] The coupling portion 2 is tightly connected to the internal structure of the first fiber core interface 11. At the same time, the coupling portion 2 is positioned as far away from the second fiber core interface 12 as possible to avoid incorrect coupling. In the disclosed embodiment, the distance between the coupling portion 2 and any first fiber core interface 11 is less than the distance between the coupling portion 2 and any second fiber core interface 12.

[0058] The single-mode optical fiber 21 has only a single core. Each single-mode optical fiber 21 is connected to a corresponding first core interface 11 , and the single-mode optical fiber 21 in the coupling portion 2 is coupled to the single core in the first core interface 11 .

[0059] In some embodiments, the remaining signal value in the single-mode optical fiber 21 or the single core in the first core interface 11 after the single-mode optical fiber 21 is coupled to the single core in the first core interface 11 can be determined by adjusting the coupling ratio during manufacturing. For example, when it is necessary to drop the signal from a specific core of the first optical fiber 10, depending on the coupling ratio during manufacturing, it can be achieved that after the single-mode optical fiber 21 is coupled to the single core in the first core interface 11, a portion (e.g., 50%) or all of the signal in the single core in the first core interface 11 is transmitted to the single-mode optical fiber 21, and then output through the single-mode optical fiber 21, thereby downloading (dropping) the optical signal. When it is necessary to load a signal to a specific core of the first optical fiber 10 through the single-mode optical fiber 21, depending on the coupling ratio during manufacturing, it can be achieved that after the single-mode optical fiber 21 is coupled with the single core in the first core interface 11, part of the signal (for example, 50%) or all of the signal in the single-mode optical fiber 21 is transmitted to the single core in the first core interface 11, and then output through the first core interface 11, thereby realizing the uploading (loading) of the optical signal.

[0060] Figures 2A to 2D are cross-sectional schematic diagrams of a core power coupler according to an embodiment of the present disclosure. The outline of the core power coupler shown in Figure 2 is for illustration only and does not limit the actual outline of the core power coupler.

[0061] Referring to Figure 2A, in one embodiment, N=1, M=3. The core power coupler 100 can be formed by approaching a multi-core optical fiber to a single-mode optical fiber core, and the direction in which the single-mode optical fiber 21 approaches the first optical fiber 10 can be used to determine which core's energy can be coupled. For example, when the single-mode optical fiber 21 is on the extension line of the diameter of the core 1, energy coupling between the core 1 and the single-mode optical fiber 21 is achieved. Since the other cores are farther away, coupling cannot be achieved. In this scenario, the interface connecting the core 1 is the first core interface 11, and the interface connecting the cores 2, 3, and 4 is the second core interface 12. By controlling the proximity distance, coupling length, and coupling ratio of the cores, partial (less than 100%) or full (100%) coupling of the energy between the core 1 and the single-mode optical fiber 21 can be achieved.

[0062] In one embodiment of the present disclosure, when it is necessary to drop a signal from a specific core of the first optical fiber 10, the connector 1 can either continue to transmit the signal from the core connected to the first core interface 11 (even if the signal is null after coupling), or only transmit the signal from the core connected to the second core interface 12. When it is necessary to add a signal to a specific core of the first optical fiber 10, the connector 1 needs to continue to transmit the signal from the core connected to the first core interface 11.

[0063] When N is greater than 1, the position and shape of the coupling portion 2 can be set according to the positions of the fiber core interfaces in the connector 1 .

[0064] 2B , when the fiber core interfaces in the connector 1 are arranged in an array, the coupling portion 2 can be disposed around the connector 1. In the left side of FIG2B , N=2, M=2, and in the right side of FIG2B , N=4, M=0.

[0065] Referring to Figure 2C , in another embodiment, when the fiber core interfaces in connector 1 are arranged in an array, coupling portion 2 can also be positioned according to the position of first fiber core interface 11. On the left side of Figure 2C , N=2, M=2, and the cross-sections of coupling portion 2 and connector 1 are both curved surfaces; on the right side of Figure 2C , N=2, M=2, and the cross-sections of coupling portion 2 and connector 1 are both rectangular.

[0066] Referring to Figure 2D , in another embodiment, the coupling portion 2 can be further divided into a plurality of sub-coupling portions 20 according to the position of the first fiber core interface 11, with each sub-coupling portion 20 corresponding to a first fiber core interface 11. In Figure 2D , N=2 and M=2 are shown on the left side, and in Figure 2D , N=4 and M=0 are shown on the right side.

[0067] In other embodiments, if the positions of the fiber core interfaces in the connector 1 are arranged in other ways, such as a straight-line arrangement, a cross-star arrangement, a triangular arrangement, etc., the coupling part 2 is also arranged accordingly according to the positions of the fiber core interfaces, and the various shapes of the coupling part 2 are all within the scope of the embodiments of the present disclosure.

[0068] 3A and 3B are output schematic diagrams of a fiber core power coupler according to an embodiment of the present disclosure.

[0069] Referring to FIG3A , in one embodiment, the second end of connector 1 has M third fiber core interfaces 13 correspondingly connected to the M second fiber core interfaces 12. The second end of connector 1 is used to connect to a second optical fiber 20. Second optical fiber 20 has M fiber cores, each of which is connected to a corresponding third fiber core interface 13. The second fiber core interfaces 12 and the third fiber core interfaces 13 are connected via a single fiber core 121.

[0070] In the embodiment shown in Figure 3A, connector 1 only outputs the signal of the fiber core connected to the second fiber core interface 12, and the signal of the fiber core connected to the first fiber core interface 11 is output by coupler 2 for processing. The connector 1 shown in Figure 3A can only achieve wave dropping of specific optical fiber signals.

[0071] Referring to FIG3B , in another embodiment, the second end of the connector 1 has N+M third fiber core interfaces 13. The second end of the connector 1 is used to connect to the second optical fiber 20. The second optical fiber 20 has N+M fiber cores, each of which is connected to a corresponding third fiber core interface 13. The second fiber core interface 12 and the third fiber core interface 13 are connected via a single fiber core 121. The N third fiber core interfaces 13 are respectively connected to the N first fiber core interfaces 12 via N single fiber cores 111.

[0072] In the embodiment shown in FIG3B , a signal may or may not exist in the single fiber core 111. In the signal dropout scenario, depending on the coupling ratio between the single fiber core 111 and the single-mode fiber 21, part of the signal or all of the signal in the single fiber core 111 is coupled into the single-mode fiber 21. When part of the signal in the single fiber core 111 is coupled into the single-mode fiber 21, part of the signal still remains in the single fiber core 111, and the intensity of this part of the signal is less than the signal intensity in the corresponding fiber core in the first optical fiber 10. When all the signals in the single fiber core 111 are coupled into the single-mode fiber 21, no signal exists in the single fiber core 111. In the signal add-in scenario, the signal from the single-mode fiber 21 is coupled into the single fiber core 111, and a signal must exist in the single fiber core 111.

[0073] The embodiment shown in FIG3B can be applied to both signal adding and signal dropping scenarios, with a wider range of application scenarios. Thus, a second optical fiber 20 having the same specifications as the first optical fiber 10 can be connected to the output end of the connector 1 to improve signal transmission quality and increase connection strength. The same specifications include, but are not limited to, the same core diameter, the same core cross-sectional shape, the same core size, the same core material, the same number of cores, the same core spacing, and the same core refractive index.

[0074] 4A to 4C are schematic diagrams of ports of a coupling portion in an embodiment of the present disclosure.

[0075] Referring to FIG4A , in one embodiment, coupling portion 2 has N first single-fiber-core signal connection ends 22 , which are arranged in the same direction as the second end of connector 1 . These N first single-fiber-core signal connection ends 22 are used to respectively connect to the N cores of a third optical fiber 30 , which is used to collect signals from the N cores of first optical fiber 10 . The embodiment shown in FIG4A can also employ the two types of third fiber-core interfaces 13 described in the embodiments shown in FIG3A and FIG3B , and their further description is omitted.

[0076] The coupling portion 2 can be connected to a subsequent optical signal processing device such as a TFF device (see subsequent embodiments) through a third optical fiber 30, thereby providing a wavelet dropping path for the optical signal.

[0077] 4B , in one embodiment, the coupling portion 2 has N second single-fiber-core signal connection ends 23 , and the second single-fiber-core signal connection ends 23 and the first end of the connector 1 are arranged in the same direction.

[0078] When a TFF device (thin film filter 75) can only be connected to one single-mode optical fiber, N second single-core signal connection ends 23 are used to respectively connect N fourth optical fibers 40, where the fourth optical fiber 40 is a single-mode optical fiber, and the fourth optical fiber 40 is used to add a signal to one core in the first optical fiber 10 to complete the signal loading.

[0079] When the input or output end of a TFF device can be connected to a multi-core optical fiber, that is, when signals from different cores are processed at different time periods through a thin film filter 75, the fourth optical fiber 40 can also be a multi-core optical fiber. The number of cores of the fourth optical fiber 40 is equal to the number of cores that can be connected to the input or output end of the thin film filter 75 used to connect the fourth optical fiber 40, and the number of fourth optical fibers 40 is equal to the ratio of N to the number of cores of the fourth optical fiber 40.

[0080] It can be understood that the embodiment shown in FIG. 4B can only be applied to the third fiber core interface 13 and the second optical fiber 20 in the embodiment shown in FIG. 3B .

[0081] The coupling portion 2 can be connected to a subsequent optical signal processing device such as a TFF device (see subsequent embodiments) through a fourth optical fiber 40, thereby providing an optical signal loading path.

[0082] By creating two fiber core power couplers 100 with different interface orientations, functional independence can be achieved, saving costs and adapting to different scenarios. Furthermore, the two fiber core power couplers can be used in conjunction with different sections of the same optical fiber to add and drop wavelengths to a specific core.

[0083] 4C , in one embodiment, a first single-core signal connection end 22 and a second single-core signal connection end 23 may be provided simultaneously. At this time, when it is necessary to perform signal addition and signal removal on a specific core in the first optical fiber 10, a core power coupler can be used to connect the specific core in the first optical fiber 10 for signal removal and signal addition, and then the signal output can be realized by connecting the second optical fiber 20 to the second end of the connector 1.

[0084] When both the first single fiber core signal connection end 22 and the second single fiber core signal connection end 23 are provided, the number of the first single fiber core signal connection end 22 and the second single fiber core signal connection end 23 may be less than N (the number of the first fiber core interfaces 11 ).

[0085] In one embodiment, a fiber cores in the first optical fiber 10 can be selected for signal dropout and b fiber cores for signal addition. If a fiber core and b fiber core do not overlap, then a+b=N (N must be greater than 1 at this time), the number of first single fiber core signal connection ends 22 is a, and the number of second single fiber core signal connection ends 23 is b.

[0086] In another embodiment, if c cores in the first optical fiber 10 are selected for signal dropout and d cores for signal addition, e cores among the c and d cores overlap, i.e., the e cores are sequentially added and dropped (or dropped and added) according to the coupling position. In this case, c + de = N (N can be greater than or equal to 1), the number of first single-core signal connection ends 22 is c, and the number of second single-core signal connection ends 23 is d. It is understood that the embodiment shown in FIG4C is applicable only to the third core interface 13 and second optical fiber 20 of the embodiment shown in FIG3B.

[0087] FIG5 is a schematic diagram of manufacturing a fiber core power coupler according to an embodiment of the present disclosure.

[0088] 5 , in one embodiment, the fiber core power coupler 100 may be manufactured by a strong coupling tapering method.

[0089] First, a single fiber core 111 set in a first fiber core interface 11 and a single-mode optical fiber 21 are placed on a flame head for tapering. Then, the temperature of the flame head and the speed of tapering are controlled to control the approach distance between the single fiber core 111 and the single-mode optical fiber 21, and the tapering length is adjusted at the same time until the single fiber core 111 and the single-mode optical fiber 21 reach the set coupling ratio.

[0090] FIG6 is a schematic diagram of manufacturing a fiber core power coupler according to another embodiment of the present disclosure.

[0091] Referring to FIG. 6 , in another embodiment, the fiber core power coupler can also be prepared by polishing.

[0092] First, place a single fiber core 111 within the first fiber core interface 11 and a single-mode fiber 21 onto the first and second bases 61 and 62, respectively. Polish the sides of the single fiber core 111 and single-mode fiber 21, respectively. Then, adjust the polishing depth (which determines the proximity of the single fiber core 111 and single-mode fiber 21) and polishing length until the single fiber core 111 and single-mode fiber 21 achieve the desired coupling ratio. Finally, use a refractive index matching solution to bond the single fiber core 111 and single-mode fiber 21, and then use UV adhesive to cure the first and second bases 61 and 62.

[0093] The embodiments of the present disclosure only use one single-mode optical fiber coupled with a single fiber core 111 as an example. In some embodiments, two or more single-mode optical fibers can also be coupled with a single fiber core 111, so that the single fiber core 111 can be transmitted to different directions, such as different thin film filters 75 (see Figure 7A), or signals from different directions, such as from different thin film filters 75 (see Figure 7A), can be coupled into the single fiber core 111.

[0094] The fiber core power coupler 100 can be used in conjunction with TFF equipment to achieve wave addition and drop of a specific fiber core.

[0095] The following shows the networking scenario of FOADM (Fixed Optical Add / Drop Multiplexer) in a multi-core optical fiber system.

[0096] 7A to 7C are schematic diagrams of a fixed optical add / drop multiplexer in an exemplary embodiment of the present disclosure.

[0097] 7A , a fixed optical add / drop multiplexer (FOADM) 700 may include:

[0098] A first connecting end 71 is used to connect to a first optical fiber 10 , where the first optical fiber 10 has N+M fiber cores, where N≥1 and M≥0;

[0099] The first fiber core power coupler 72, as shown in the above embodiment, is connected to the first connection end 71 to connect to the first optical fiber 10, and the first fiber core power coupler 72 has N first fiber core interfaces and M second fiber core interfaces;

[0100] The second connecting end 73 is used to connect to the fifth optical fiber 50, and the fifth optical fiber 50 has P+M cores, where P≥1;

[0101] The second fiber core power coupler 74, as shown in the above embodiment, is connected to the second connection end 73 to connect to the fifth optical fiber 50. The second fiber core power coupler 74 has P first fiber core interfaces and M second fiber core interfaces;

[0102] One or more thin film filters 75, the thin film filter 75 is used to connect the coupling part of the first fiber core power coupler 72 through the third optical fiber 30, and to connect the coupling part of the second fiber core power coupler 74 through the fourth optical fiber 40. The thin film filter 75 is used to perform at least one of the following functions: filtering and passing the signal from the third optical fiber 30, wave-adding the signal to the third optical fiber 30, filtering and passing the signal from the fourth optical fiber 40, and wave-adding the signal to the fourth optical fiber 40.

[0103] The third optical fiber 30 is provided with a first power monitor 31, and the fourth optical fiber 40 is provided with a second power monitor 41. Those skilled in the art may install power monitors in multiple locations, and this disclosure does not impose any particular limitation thereto. The first fiber core power coupler 72 and the second fiber core power coupler 74 are as shown in any of the above embodiments.

[0104] In one embodiment of the present disclosure, the fixed optical add / drop multiplexer 700 further includes a second optical fiber 20, which is connected between the first core power coupler 72 and the second core power coupler 74. In one embodiment, the second optical fiber 20 has M cores. When M=0, the second optical fiber 20 may not be provided.

[0105] In some embodiments, P=N, that is, the number of first core interfaces of the first core power coupler 72 is equal to the number of first core interfaces of the second core power coupler 74. In other embodiments, P is greater than or less than N.

[0106] In some embodiments, the thin film filter 75 can only be used to perform signal pass-through, filtering, and other signal drop-out operations, or can only be used to perform signal upload operations. In other embodiments, the thin film filter 75 can simultaneously perform signal pass-through, filtering, and other signal drop-out operations, as well as signal upload operations.

[0107] In some embodiments, when the thin film filter 75 is only used to perform signal dropout operations such as signal pass-through and filtering, or is only used to perform signal dropout operations, the input end of one side of the thin film filter 75 can generally only be connected to a single-mode optical fiber. In other embodiments, the input end of one side of the thin film filter 75 can also be connected to multiple single-mode optical fibers, or a multi-core optical fiber.

[0108] When thin film filter 75 is only used for signal dropout operations such as signal pass-through and filtering, or is only used for signal addition operations, and the input end of one side of thin film filter 75 can only be connected to a single-mode optical fiber, thin film filter 75 can be used for signal dropout only, signal addition only, or both signal dropout and pass-through. If N>1 or P>1, multiple thin film filters 75 are present.

[0109] at this time:

[0110] (1) If the thin film filter 75 is only used for signal dropout, N thin film filters 75 can be provided and connected to the first core power coupler 72 through N third optical fibers 30 .

[0111] (2) If the thin film filter 75 is used only for signal addition, P thin film filters 75 may be provided and connected to the second core power coupler 74 through P fourth optical fibers 40 , respectively.

[0112] (3) If N thin film filters 75 are used for signal filtering and pass-through, the N thin film filters 75 can be connected to the first core power coupler 72 through N third optical fibers 30 respectively, and at the same time, the N thin film filters 75 are connected to the second core power coupler 74 through N fourth optical fibers 40 respectively.

[0113] Therefore, when there are multiple thin film filters 75, if some of the thin film filters 75 are used for signal dropout, some for signal add-in, and some for signal pass-through and dropout, and one thin film filter 75 is connected to at least one third optical fiber 30 and / or fourth optical fiber 40, the number of thin film filters 75 is greater than or equal to the maximum of N or P, and less than N + P. The number of third optical fibers 30 is equal to N, and the number of fourth optical fibers 40 is equal to P.

[0114] Those skilled in the art can set the number and connection relationship of the thin film filters 75 according to signal processing requirements, and the present disclosure does not impose any special restrictions on this.

[0115] The first connection end 71 and the second connection end 73 are both multi-core fiber LC connectors. The LC connector is a miniaturized fiber optic connector that is very suitable for high-density construction environments. The LC connector has two semi-inserted ceramic sleeves, which are separated by a finely processed and docked ceramic or plastic sleeve to ensure precise alignment between the optical fibers. The LC connector adopts a lead-type structure, with a plug-in and unplug cycle of up to 500 to 1000 times and a long service life. In fiber optic transmission systems, the LC connector can be used to connect single-mode and multi-mode optical fibers, and has the advantages of low insertion loss, low return loss, high stability, and good reliability.

[0116] The first optical fiber 10 and the fifth optical fiber 50 are connected to the first core coupler 72 and the second core coupler 74 in the device 700 through the first connection end 71 and the second connection end 73, and the splitting of one or some cores is achieved through the coupling part of the first core coupler 72 or the coupling part of the second core coupler 74.

[0117] When the signal is transmitted from the first optical fiber 10 to the fifth optical fiber 50, for the wavelength drop signal (signal drop), the optical signal of a certain core after being split by the first core coupler 72 passes through the third optical fiber 30 to a thin film filter 75, i.e., a TFF device. The thin film filter 75 then sends several (4 in the figure as an example) fixed wavelength signals to the signal output end 76, and passes the signals of other wavelengths through the fourth optical fiber 40 to the single-mode optical fiber of the coupling part in the second core coupler 74, and couples the signal to a certain core in the fifth optical fiber 50 through the second core coupler 74, completing the signal drop and pass-through.

[0118] 7B , in some embodiments, other wavelength signals may not be retained or passed through. In this case, the fourth optical fiber 40 may not be provided, and even the second core coupler 74 and the second optical fiber 20 may not be provided. The second connecting end 73 may be directly connected to the right side of the first core coupler 72. Furthermore, the first connecting end 71 and the second connecting end 73 may not be provided, and the first optical fiber 10 may be directly connected to the left side of the first core coupler 72, and the fifth optical fiber 50 may be connected to the right side of the first core coupler 72.

[0119] Continuing to refer to Figure 7A, for the wavelength adding signal (signal adding), the optical signal of a certain core after being split by the first core coupler 72 reaches a thin film filter 75, i.e., a TFF device, through the third optical fiber 30, and is then wavelength-combined with several (4 in the figure as an example) fixed wavelengths from the signal input end 77 through the thin film filter 75 to achieve wavelength adding, and then transmitted through the fourth optical fiber 40 to the single-mode optical fiber of the coupling part of the second core coupler 74, and coupled to the fifth optical fiber 50 to complete the signal adding.

[0120] 7C , in some embodiments, the signal in the first optical fiber 10 may not be split, and the fourth optical fiber 40 and the second core coupler 74 may be used to directly add the signal to a core of the fifth optical fiber 50. In this case, the third optical fiber 30 and even the first core coupler 72 and the second optical fiber 20 may not be provided, and the first optical fiber 10 may be directly connected to the left side of the second core coupler 74. Furthermore, the first connecting end 71 and the second connecting end 73 may not be provided, and the first optical fiber 10 may be directly connected to the left side of the second core coupler 74, and the fifth optical fiber 50 may be connected to the right side of the second core coupler 74.

[0121] When the signal is transmitted from the fifth optical fiber 50 to the first optical fiber 10 , the path is opposite, but the principle is the same, and details will not be repeated here.

[0122] The above signal adding and dropping process is illustrated below with reference to the accompanying drawings.

[0123] 8A to 8C are schematic diagrams of a fixed optical add / drop multiplexer 700 for completing signal addition and removal in accordance with an embodiment of the present disclosure. In the embodiment shown in FIG8A to FIG8C , the first optical fiber 10 is used for inputting signals, and the fifth optical fiber 50 is used for outputting signals.

[0124] Referring to FIG8A , in one embodiment, a thin film filter 75 has a signal output terminal 76. The thin film filter 75 filters the signal from one of the N cores of the third optical fiber 30 to output a first signal S1 through the signal output terminal 76 while retaining a second signal S2. The thin film filter 75 transmits the second signal S2 through one core of the fourth optical fiber 40 to the second core power coupler 74 for transmission to the fifth optical fiber 50. FIG8A illustrates only one thin film filter 75. In other embodiments, multiple thin film filters 75 may be provided to respectively filter and transmit signals from the N cores of the first optical fiber 10.

[0125] Referring to FIG8B , in another embodiment, one thin film filter 75 has a signal output terminal 76, and another thin film filter 75 has a signal input terminal 77. Each thin film filter 75 can only perform wave addition or wave removal, but not both. Multiple thin film filters 75 are connected to the second core power coupler 74 via different fourth optical fibers 40 (single-mode optical fibers).

[0126] A thin film filter 75 having a signal output end 76 filters the signal from the third optical fiber 30, outputs the first signal S1 through the signal output end 76, retains the second signal S2, and passes the second signal S2 through a fourth optical fiber 40 to the second fiber core power coupler 74; a thin film filter 75 having a signal input end 77 receives the third signal S3 through the signal input end 77, and up-waves the third signal S3 to the second fiber core power coupler 74 through another fourth optical fiber 40; depending on the different internal manufacturing processes of the second fiber core power coupler 74, the second fiber core power coupler 74 can transmit the second signal S2 and the third signal S3 to different cores of the fifth optical fiber 50 respectively, or can transmit the second signal S2 and the third signal S3 to the same core of the fifth optical fiber 50.

[0127] FIG8B illustrates only one thin film filter 75 for signal pass-through and one thin film filter 75 for signal addition. In other embodiments, multiple thin film filters 75 may be provided to filter and pass-through the signals of the N cores of the first optical fiber 10, and / or to add signals to one or more cores of the fifth optical fiber 50. It should be noted that different thin film filters 75 correspond to different signal output ports 76 and signal input ports 77.

[0128] Referring to Figure 8C , in yet another embodiment, a thin film filter 75 includes a signal input port 77 . The thin film filter 75 receives a third signal S3 via the signal input port 77 and then transmits the third signal S3 to the second core power coupler 74 via a fourth optical fiber 40 . The embodiment shown in Figure 8C allows for optical fiber signal addition only. Figure 8C illustrates only one thin film filter 75 . In other embodiments, multiple thin film filters 75 may be provided to separately add signals to one or more cores of the fifth optical fiber 50 .

[0129] Figures 9A to 9C are schematic diagrams of a fixed optical add / drop multiplexer 700 for signal addition and drop in an embodiment of the present disclosure. In the embodiment shown in Figures 9A to 9C, the fifth optical fiber 50 is used for inputting signals, and the first optical fiber 10 is used for outputting signals.

[0130] Referring to FIG9A , in one embodiment, a thin film filter 75 has a signal output terminal 76 . The thin film filter 75 filters a signal from one of the P fourth optical fibers 40 to output a first signal S1 through the signal output terminal 76 while retaining a second signal S2 . The thin film filter 75 then transmits the second signal S2 to the first fiber core power coupler 72 via the third optical fiber 30 . FIG9A illustrates only one thin film filter 75 . In other embodiments, multiple thin film filters 75 may be provided to filter and pass signals from multiple cores of the fifth optical fiber 50 , respectively.

[0131] Referring to FIG9B , in another embodiment, one thin film filter 75 has a signal output terminal 76, and another thin film filter 75 has a signal input terminal 77. Each thin film filter 75 can only perform wave addition or wave removal, but not both. Multiple thin film filters 75 are connected to the first core power coupler 72 via different third optical fibers 30.

[0132] A thin film filter 75 having a signal output end 76 filters a signal from a fourth optical fiber 40, outputs a first signal S1 through the signal output end 76, retains the second signal S2, and transmits the second signal S2 to the first fiber core power coupler 72 through a third optical fiber 30; a thin film filter 75 having a signal input end 77 receives a third signal S3 through the signal input end 77, and transmits the third signal S3 to the first fiber core power coupler 72 through another third optical fiber 30; depending on the different internal manufacturing processes of the first fiber core power coupler 72, the first fiber core power coupler 72 can transmit the second signal S2 and the third signal S3 to two different fiber cores of the first optical fiber 10 respectively, or can transmit the second signal S2 and the third signal S3 to the same fiber core of the first optical fiber 10.

[0133] FIG9B illustrates only one thin film filter 75 for pass-through and one thin film filter 75 for adding wavelengths. In other embodiments, multiple thin film filters 75 may be provided to filter and pass-through the signals of multiple fourth optical fibers 40, and / or to add wavelengths to one or more cores of the first optical fiber 10. Different thin film filters 75 correspond to different signal output ports 76 and signal input ports 77.

[0134] Referring to FIG9C , in yet another embodiment, a thin film filter 75 includes a signal input port 77 that receives a third signal S3 and transmits the third signal S3 to the first core power coupler 72 via a fourth optical fiber 40. The embodiment shown in FIG9C allows for transmitting signals only to the optical fiber. FIG9C illustrates only one thin film filter 75. In other embodiments, multiple thin film filters 75 may be provided to transmit signals to one or more cores of the first optical fiber 10.

[0135] In addition to using different thin film filters 75 to perform signal loading, signal filtering, and signal pass-through as described above, in other embodiments of the present disclosure, a single thin film filter 75 can be used to connect multiple third optical fibers 30 and multiple fourth optical fibers 40 to sequentially filter and pass through different signals, or sequentially load signals from different fiber cores, or filter and pass through a signal from a specific fiber core of an input optical fiber (first optical fiber 10 or fifth optical fiber 50) at a first time point and then load the signal from that fiber core at a second time point, the first and second time points being different time points. In this case, the thin film filter 75 can have both a signal output port 76 and a signal input port 77.

[0136] In the embodiment of the present disclosure, the multi-core optical fiber is connected to the fixed optical add-drop multiplexer 700 through an LC connector. First, the optical fiber signal of a specific core is split through a core power coupler, and then a fixed add / drop operation is implemented through a thin film filter 75. After passing through the thin film filter 75, the core signal is transmitted with other core signals in the same multi-core optical fiber through another core power coupler.

[0137] The disclosed embodiment can realize the wave addition and subtraction of specific cores in a multi-core optical fiber system. Compared with the existing solution, it avoids the introduction of fan-in and fan-out devices, reduces the impact on other cores, and greatly reduces costs.

[0138] It should be noted that although several modules or units of the device for action execution are mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more modules or units described above can be concretized in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided into multiple modules or units to be concretized.

[0139] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the claims. Industrial Applicability

[0140] The core power coupler provided in the disclosed embodiments can extract signals from specific cores in a multi-core optical fiber (signal dropout) or add signals to specific cores in a multi-core optical fiber (signal add-in) without increasing link loss. A FOADM device using this core power coupler can add or drop signals to specific cores in a multi-core optical fiber with extremely low link loss and cost.

Claims

1. An optical fiber core power coupler, characterized in that, Comprising: A connector, the first end of the connector having N first core interfaces and M second core interfaces, the first end of the connector being used to connect a first optical fiber, the first optical fiber having N + M cores, each core corresponding to connect to one of the first core interfaces or one of the second core interfaces, N ≥ 1, M ≥ 0; A coupling part, internally provided with N single-mode optical fibers, each single-mode optical fiber being respectively coupled to one of the first core interfaces, the coupling part being used to couple the signal of the core connected to the first core interface into the single-mode optical fiber, or to couple the signal of the single-mode optical fiber into the core connected to the first core interface.

2. The core power coupler according to claim 1, characterized in that, The second end of the connector has M third core interfaces correspondingly connected to the M second core interfaces, the second end of the connector being used to connect a second optical fiber, the second optical fiber having M cores, each core of the second optical fiber corresponding to connect to one of the third core interfaces.

3. The core power coupler according to claim 1, characterized in that The second end of the connector has N + M third core interfaces correspondingly connected to the N first core interfaces and the M second core interfaces, the second end of the connector being used to connect a second optical fiber, the second optical fiber having N + M cores, each core of the second optical fiber corresponding to connect to one of the third core interfaces.

4. The core power coupler according to claim 1, characterized in that, The coupling part has one or more first single-core signal connection ends, the first single-core signal connection ends being arranged on one side of the second end of the connector, the first single-core signal connection ends being used to connect the cores of a third optical fiber, the third optical fiber being used to perform signal down-conversion on the cores connected to the first core interfaces, or to perform signal down-conversion and pass-through.

5. The core power coupler according to claim 1 or 4, characterized in that, The coupling part has one or more second single-core signal connection ends, the second single-core signal connection ends being arranged on one side of the first end of the connector, the second single-core signal connection ends being used to connect the cores of a fourth optical fiber, the fourth optical fiber being used to perform signal up-conversion on the cores connected to the first core interfaces.

6. The core power coupler according to claim 1, characterized in that, The distance between the coupling part and any one of the first core interfaces is less than the distance between the coupling part and any one of the second core interfaces.

7. The core power coupler according to any one of claims 1-6, characterized in that The coupling part is manufactured by the following method: Placing the single core arranged in one of the first core interfaces and a single-mode optical fiber correspondingly on a flame head for tapering; Controlling the temperature of the flame head and the speed of tapering to control the approaching distance between the single core and the single-mode optical fiber, thereby adjusting the tapering length until the single core and the single-mode optical fiber reach a set coupling ratio.

8. The core power coupler according to any one of claims 1-6, characterized in that, The coupling part is manufactured by the following method: Placing the single core arranged in one of the first core interfaces and a single-mode optical fiber on a first base and a second base respectively, and polishing the sides of the single core and the single-mode optical fiber respectively; Adjusting the polishing depth, polishing length and the approaching distance between the single core and the single-mode optical fiber until the single core and the single-mode optical fiber reach a set coupling ratio; Using a refractive index matching liquid to make the single core and the single-mode optical fiber fit together, and using ultraviolet glue to cure the first base and the second base.

9. An optical add-drop multiplexer, characterized in that, Comprising: A first connection end for connecting a first optical fiber, the first optical fiber having N + M cores, where N ≥ 1 and M ≥ 0; A first core power coupler, as described in any one of claims 1 - 8, connected to the first connection end to connect the first optical fiber, the first core power coupler having N first core interfaces and M second core interfaces; A second connection end for connecting a fifth optical fiber, the fifth optical fiber having P + M cores, where P ≥ 1; A second core power coupler, as described in any one of claims 1 - 8, connected to the second connection end to connect the fifth optical fiber, the second core power coupler having P first core interfaces and M second core interfaces; One or more thin - film filters, the thin - film filters being used to connect to the coupling part of the first core power coupler through a third optical fiber and to connect to the coupling part of the second core power coupler through a fourth optical fiber, the thin - film filters being used to perform at least one of the following functions: filtering and passing signals from the third optical fiber, up - converting signals on the third optical fiber, filtering and passing signals from the fourth optical fiber, up - converting signals on the fourth optical fiber.

10. The fixed optical add-drop multiplexer according to claim 9, characterized in that, The first optical fiber is used for inputting signals, the thin - film filter has a signal output end, the thin - film filter is connected to the third optical fiber, and the thin - film filter is used to filter signals from the third optical fiber to output a first signal through the signal output end.

11. The fixed optical add-drop multiplexer according to claim 10, wherein The thin - film filter is further connected to the fourth optical fiber, the thin - film filter is used to filter signals from the third optical fiber to output a first signal through the signal output end, retain a second signal, and transmit the second signal to the second core power coupler through the fourth optical fiber.

12. The fixed optical add-drop multiplexer according to claim 9, wherein The first optical fiber is used for inputting signals, the fifth optical fiber is used for outputting signals, the thin - film filter is connected to the fourth optical fiber, the thin - film filter has a signal input end, the thin - film filter receives a third signal through the signal input end and transmits the third signal to the second core power coupler through the fourth optical fiber.

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