Optical fiber branching and switching device

Abstract

To provide an optical fiber branch switch device for branch-switching a multi-core fiber to a multi-core fiber.SOLUTION: An optical fiber branch switch device 100 includes a first optical fiber 101, a second optical fiber 102, a third optical fiber 103, a plurality of fourth optical fibers 104, a plurality of fifth optical fibers 105, and a plurality of sixth optical fibers 106. The first optical fiber is connected to the second optical fiber by the fourth optical fibers. The first optical fiber is connected to the third optical fiber by the fifth optical fibers. The second optical fiber is connected to the third optical fiber by the sixth optical fibers.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an optical fiber branching switching device. [Background Art]

[0002] Patent Document 1 discloses a communication system including three or more nodes, in which a multi-core fiber including a plurality of cores in at least some sections among connections between the nodes is used. A node connected to a multi-core fiber includes a connector that inserts and drops a signal into / from a core exclusively allocated to communication between another node and the own node. The connector relays a signal transmitted by a core allocated to communication between other nodes in the multi-core fiber connected to the own node.

[0003] Patent Document 2 discloses a communication system including three or more nodes, in which a multi-core fiber including a plurality of cores in at least some sections among connections between the nodes is used. The communication system includes a detection signal output unit that outputs a failure detection signal to be transmitted through a core provided in the multi-core fiber connecting the nodes. The communication system also includes a failure detection unit that determines whether a failure has occurred between the nodes based on the detection result of the failure detection signal. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2017 / 090600 [Patent Document 2] International Publication No. 2017 / 090611 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] Patent documents 1 and 2 convert multicore fibers to single fibers by fan-in and fan-out. However, no optical fiber branching and switching device for branching and switching multicore fibers has been disclosed. Therefore, the object of this disclosure is to provide an optical fiber branching and switching device for branching and switching multicore fibers. [Means for solving the problem]

[0006] The optical fiber branching and switching equipment relating to this disclosure is It comprises a first optical fiber, a second optical fiber, a third optical fiber, a plurality of fourth optical fibers, a plurality of fifth optical fibers, and a plurality of sixth optical fibers. The first optical fiber is connected to the second optical fiber and a plurality of the fourth optical fibers, The first optical fiber is connected to the third optical fiber and a plurality of the fifth optical fibers, This is an optical fiber branching and switching device in which the second optical fiber is connected to the third optical fiber using a plurality of the sixth optical fibers.

[0007] Furthermore, another optical fiber branching and switching device related to this disclosure is It comprises a first optical fiber, a second optical fiber, a third optical fiber, a fourth optical fiber, a plurality of fifth optical fibers, a plurality of sixth optical fibers, and a plurality of seventh optical fibers. The first optical fiber is connected to the second optical fiber using a plurality of the fifth optical fibers. The first optical fiber is connected to the third optical fiber using a plurality of the sixth optical fibers, This is an optical fiber branching and switching device in which the second optical fiber is connected to the fourth optical fiber and a plurality of seventh optical fibers.

[0008] Furthermore, another optical fiber branching and switching device related to this disclosure is A first optical fiber having a first number of cores, a second optical fiber having a second number of cores, a third optical fiber having a third number of cores, and a fourth optical fiber having a fourth number of cores, It comprises a first switching device and a second switching device, The first plurality of cores are connected to the third plurality of cores, The second plurality of cores are connected to the fourth plurality of cores, This is an optical fiber branching and switching device in which the first plurality of cores are connected to the second plurality of cores via the first switching device and the second switching device.

[0009] Furthermore, another optical fiber branching and switching device related to this disclosure is The first optical fiber, the second optical fiber, the third optical fiber, the fourth optical fiber, the fifth optical fiber, the sixth optical fiber, the seventh optical fiber, the eighth optical fiber, multiple ninth optical fibers, multiple tenth optical fibers, multiple eleventh optical fibers, multiple twelfth optical fibers, It comprises a first switching device, a second switching device, a third switching device, and a fourth switching device. The first optical fiber is connected to the sixth optical fiber and a plurality of the ninth optical fibers, The second optical fiber is connected to the fifth optical fiber using a plurality of the tenth optical fibers. The third optical fiber is connected to the seventh optical fiber using a plurality of the eleventh optical fibers. The fourth optical fiber is connected to the eighth optical fiber and a plurality of the twelfth optical fibers. Multiple 9 optical fibers are connected to multiple 11 optical fibers via the first and second switching devices. This is an optical fiber branching and switching device in which a plurality of the 10 optical fibers are connected to a plurality of the 12 optical fibers via the third switching device and the fourth switching device.

[0010] Furthermore, another optical fiber branching and switching device described herein is It comprises a first optical fiber, a second optical fiber, a third optical fiber, a fourth optical fiber, a fifth optical fiber, a sixth optical fiber, a seventh optical fiber, a plurality of eighth optical fibers, a plurality of ninth optical fibers, a plurality of tenth optical fibers, and a plurality of eleventh optical fibers. The first optical fiber is connected to the fifth optical fiber and a plurality of the eighth optical fibers, The second optical fiber is connected to the fifth optical fiber using a plurality of the ninth optical fibers. The third optical fiber is connected to the sixth optical fiber using a plurality of the tenth optical fibers. The fourth optical fiber is an optical fiber branching and switching device connected to the seventh optical fiber and a plurality of the eleventh optical fibers.

[0011] Furthermore, another optical fiber branching and switching device described herein is A first optical fiber, a second optical fiber, a third optical fiber, a fourth optical fiber, multiple fifth optical fibers, multiple sixth optical fibers, multiple seventh optical fibers, multiple eighth optical fibers, It comprises a first switching device and a second switching device, The first optical fiber is connected to the third optical fiber using a plurality of the fifth optical fiber and a plurality of the sixth optical fiber. The aforementioned second optical fiber is connected to the aforementioned fourth optical fiber using a plurality of the aforementioned seventh optical fiber and a plurality of the aforementioned eighth optical fiber. This is an optical fiber branching and switching device in which a plurality of the fifth optical fibers are connected to a plurality of the seventh optical fibers via the first and second switching devices.

[0012] Furthermore, another optical fiber branching and switching device described herein is comprising a first optical fiber, a second optical fiber, a third optical fiber, a plurality of fourth optical fibers, a plurality of fifth optical fibers, a sixth optical fiber, and a seventh optical fiber, the first optical fiber is connected to the second optical fiber by using the plurality of fourth optical fibers, the first optical fiber is connected to the third optical fiber by using the plurality of fifth optical fibers, the second optical fiber is connected to the sixth optical fiber, which is an optical fiber branching and switching device wherein the second optical fiber is connected to the seventh optical fiber. Effects of the Invention

[0013] According to the present disclosure, an optical fiber branching and switching device that branches and switches a multi-core fiber to another multi-core fiber can be provided. Brief Description of the Drawings

[0014] [Figure 1] FIG. 1 is a schematic diagram of the optical fiber branching and switching device according to the first embodiment. [Figure 2] FIG. 2 is a schematic diagram of another optical fiber branching and switching device according to the first embodiment. [Figure 3] FIG. 3 is a schematic diagram of another optical fiber branching and switching device according to the first embodiment. [Figure 4] FIG. 4 is a schematic diagram of another optical fiber branching and switching device according to the first embodiment. [Figure 5] FIG. 5 is a schematic diagram of the optical fiber branching and switching device according to the second embodiment. [Figure 6] FIG. 6 is a schematic diagram of another optical fiber branching and switching device according to the second embodiment. [Figure 7] FIG. 7 is a schematic diagram of another optical fiber branching and switching device according to the second embodiment. [Figure 8] FIG. 8 is a schematic diagram of another optical fiber branching and switching device according to the second embodiment. [Figure 9]This is a schematic diagram of an optical fiber branching and switching device according to Embodiment 3. [Figure 10] This is a schematic diagram of an optical fiber branching and switching device according to Embodiment 3. [Figure 11] This is a schematic diagram of an optical fiber branching and switching device according to Embodiment 4. [Figure 12] This is a schematic diagram of an optical fiber branching and switching device according to Embodiment 4. [Figure 13] This is a schematic diagram of an optical fiber branching and switching device according to Embodiment 4. [Figure 14] This is a schematic diagram of an optical fiber branching and switching device according to Embodiment 5. [Figure 15] This is a schematic diagram of another optical fiber branching and switching device according to Embodiment 5. [Figure 16] This is a schematic diagram of another optical fiber branching and switching device according to Embodiment 5. [Figure 17] This is a schematic diagram of another optical fiber branching and switching device according to Embodiment 5. [Figure 18] This is a schematic diagram of an optical fiber branching and switching device according to Embodiment 6. [Figure 19] This is a schematic diagram of an optical fiber branching and switching device according to Embodiment 6. [Figure 20] This is a schematic diagram of an optical fiber branching and switching device according to Embodiment 6. [Figure 21] This is a schematic diagram of the optical fiber branching and switching device according to Embodiment 7. [Figure 22] This is a schematic diagram of another optical fiber branching and switching device according to Embodiment 7. [Figure 23] This is a schematic diagram of another optical fiber branching and switching device according to Embodiment 7. [Figure 24] This is a schematic diagram of another optical fiber branching and switching device according to Embodiment 7. [Figure 25] This is a schematic diagram of another optical fiber branching and switching device according to Embodiment 7. [Modes for carrying out the invention]

[0015] Embodiment Embodiments of this disclosure will be described below with reference to the drawings. However, the claims are not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential for solving the problem. For clarity of explanation, the following descriptions and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are denoted by the same reference numerals, and redundant explanations have been omitted where necessary.

[0016] (Description of the optical fiber branching and switching device according to Embodiment 1) Figure 1 is a schematic diagram of an optical fiber branching and switching device according to Embodiment 1. Figures 2 to 4 are schematic diagrams of other optical fiber branching and switching devices according to Embodiment 1. The optical fiber branching and switching device according to Embodiment 1 will be described with reference to Figures 1 to 4.

[0017] Referring to Figure 1, the optical fiber branching and switching device 100 according to Embodiment 1 includes a first optical fiber 101, a second optical fiber 102, a third optical fiber 103, a plurality of fourth optical fibers 104, a plurality of fifth optical fibers 105, and a plurality of sixth optical fibers 106. The optical fiber branching and switching device 100 according to this embodiment uses a FIFO: multicore fiber fan-in / fan-out device.

[0018] The first optical fiber 101 is connected via an optical fiber branching and switching device 100 using the second optical fiber 102 and a plurality of fourth optical fibers 104. The first optical fiber 101 is connected via an optical fiber branching and switching device 100 using the third optical fiber 103 and a plurality of fifth optical fibers 105. The second optical fiber 102 is connected via an optical fiber branching and switching device 100 using the third optical fiber 103 and a plurality of sixth optical fibers 106.

[0019] The first optical fiber 101 has a first plurality of cores. The first plurality of cores of the first optical fiber 101 are fanned in and fanned out into a plurality of fourth optical fibers 104 and a plurality of fifth optical fibers 105 within the optical fiber branching and switching device 100. A multicore fiber fan-in / fan-out device is placed between the first optical fiber 101 and the fourth optical fiber 104. That is, the elongated rectangle shown between the first optical fiber 101 and the fourth optical fiber 104 is the multicore fiber fan-in / fan-out device.

[0020] The second optical fiber 102 has a second set of cores. The second set of cores of the second optical fiber 102 is fanned in and fanned out into a plurality of fourth optical fibers 104 and a plurality of sixth optical fibers 106 within the optical fiber branching and switching device 100. A multicore fiber fan-in / fan-out device is provided between the fourth optical fiber 104 and the sixth optical fiber 106. The multicore fiber fan-in / fan-out device is positioned between the second optical fiber 102 and the fourth optical fiber 104. In other words, the elongated rectangle shown between the second optical fiber 102 and the fourth optical fiber 104 is the multicore fiber fan-in / fan-out device.

[0021] The third optical fiber 103 has a third set of cores. The third set of cores of the third optical fiber 103 is fanned in and fanned out into a plurality of fifth optical fibers 105 and a plurality of sixth optical fibers 106 within the optical fiber branching and switching device 100. A multicore fiber fan-in / fan-out device is placed between the third optical fiber 103 and the fifth optical fiber 105. The elongated rectangle shown between the third optical fiber 103 and the fifth optical fiber 105 is the multicore fiber fan-in / fan-out device.

[0022] By using such an optical fiber branching and switching device 100, it is possible to branch and switch a multicore fiber to another multicore fiber.

[0023] Referring to Figure 2, the optical fiber branching and switching device 200 according to Embodiment 1 further comprises a first switching device 201 and a second switching device 202, in addition to the configuration of the optical fiber branching and switching device 100. In the optical fiber branching and switching device 200, a plurality of fifth optical fibers 105 are connected to a plurality of sixth optical fibers 106 via the first switching device 201 and the second switching device 202.

[0024] By using such an optical fiber branching and switching device 200, the multicore fiber of the first optical fiber 101 can be connected to the multicore fiber of the second optical fiber 102.

[0025] Figure 3 shows the direction of signal input and output for the optical fiber branching and switching device 200 according to Embodiment 1. As shown in Figure 3, the fourth optical fiber 104 has a line through which the signal is input from the second optical fiber 102 and output to the first optical fiber 101. Multiple fourth optical fibers 104 transmit signals in only one direction. The fifth optical fiber 105 has a line through which the signal is input from the first optical fiber 101 and output to the third optical fiber 103. Multiple fifth optical fibers 105 transmit signals in only one direction. The sixth optical fiber 106 has a line through which the signal is input from the third optical fiber 103 and output to the second optical fiber 102. Multiple sixth optical fibers 106 transmit signals in only one direction.

[0026] With this configuration, the first optical fiber 101, which is a multicore fiber, can transmit both transmit and receive signals. The second optical fiber 102, which is also a multicore fiber, can transmit both transmit and receive signals. Furthermore, the third optical fiber 103, which is also a multicore fiber, can transmit both transmit and receive signals.

[0027] Figure 4 shows the direction of signal incidence and emission for the optical fiber branching and switching device 200 according to Embodiment 1. As shown in Figure 4, the plurality of fourth optical fibers 104 include lines through which the signal is incident from the first optical fiber 101 and emitted from the second optical fiber 102, and lines through which the signal is incident from the second optical fiber 102 and emitted from the first optical fiber 101. The plurality of fourth optical fibers 104 transmit signals bidirectionally. The plurality of fifth optical fibers 105 include lines through which the signal is incident from the first optical fiber 101 and emitted from the third optical fiber 103, and lines through which the signal is incident from the third optical fiber 103 and emitted from the first optical fiber 101. The plurality of fifth optical fibers 105 transmit signals bidirectionally. The plurality of sixth optical fibers 106 include lines through which the signal is incident from the second optical fiber 102 and emitted from the third optical fiber 103, and lines through which the signal is incident from the third optical fiber 103 and emitted from the second optical fiber 102. Multiple sixth optical fibers 106 transmit signals bidirectionally. The line from which the signal of the fifth optical fiber 105 enters from the first optical fiber 101 and exits from the third optical fiber 103 is connected to the line from which the signal of the sixth optical fiber 106 enters from the third optical fiber 103 and exits from the second optical fiber 102. This connection is made via the first switching device 201 and the second switching device 202. The line from which the signal of the fifth optical fiber 105 enters from the third optical fiber 103 and exits from the first optical fiber 101 is connected to the line from which the signal of the sixth optical fiber 106 enters from the second optical fiber 102 and exits from the third optical fiber 103. This connection is made via the first switching device 201 and the second switching device 202.

[0028] With this configuration, the first optical fiber 101, which is a multicore fiber, can transmit both transmit and receive signals. The second optical fiber 102, which is also a multicore fiber, can transmit both transmit and receive signals. Furthermore, the third optical fiber 103, which is also a multicore fiber, can transmit both transmit and receive signals.

[0029] (Description of the optical fiber branching and switching device according to Embodiment 2) Figure 5 is a schematic diagram of an optical fiber branching and switching device according to Embodiment 2. Figures 6 to 8 are schematic diagrams of another optical fiber branching and switching device according to Embodiment 2. The optical fiber branching and switching device according to Embodiment 2 will be described with reference to Figures 5 to 8.

[0030] Referring to Figure 5, the optical fiber branching and switching device 500 according to Embodiment 2 includes a first optical fiber 501, a second optical fiber 502, a third optical fiber 503, a fourth optical fiber 504, a plurality of fifth optical fibers 505, a plurality of sixth optical fibers 506, and a plurality of seventh optical fibers 507.

[0031] The first optical fiber 501 is connected to the second optical fiber 502 via an optical fiber branching and switching device 500 using a plurality of fifth optical fibers 505. The first optical fiber 501 is connected to the third optical fiber 503 via an optical fiber branching and switching device 500 using a plurality of sixth optical fibers 506. The second optical fiber 102 is connected to the fourth optical fiber 504 via an optical fiber branching and switching device 500 using a plurality of seventh optical fibers.

[0032] The first optical fiber 501 comprises a first plurality of cores. The first plurality of cores of the first optical fiber 501 are fanned in and fanned out into a plurality of fifth optical fibers 505 and a plurality of sixth optical fibers 506 within the optical fiber branching and switching device 500, and then separated.

[0033] The second optical fiber 502 has a second set of cores. The second set of cores of the second optical fiber 502 is fanned in and fanned out to a plurality of fifth optical fibers 505 and a plurality of seventh optical fibers 507 within the optical fiber branching and switching device 500.

[0034] The third optical fiber 503 has a third set of cores. The third set of cores of the third optical fiber 503 is fanned in and fanned out into a set of sixth optical fibers 506 within the optical fiber branching and switching device 500.

[0035] The fourth optical fiber 504 has a fourth set of cores. The fourth set of cores of the fourth optical fiber 504 is fanned in and fanned out into a set of seventh optical fibers 507 within the optical fiber branching and switching device 500 and then separated.

[0036] By using such an optical fiber branching and switching device 500, it is possible to branch and switch a multicore fiber to another multicore fiber.

[0037] Referring to Figure 6, the optical fiber branching and switching device 600 according to Embodiment 2 further comprises a first switching device 601 and a second switching device 602, in addition to the configuration of the optical fiber branching and switching device 500. In the optical fiber branching and switching device 600, a plurality of sixth optical fibers 506 are connected to a plurality of seventh optical fibers 507 via the first switching device 601 and the second switching device 602.

[0038] By using such an optical fiber branching and switching device 600, the multicore fiber of the first optical fiber 501 can be connected to the multicore fiber of the second optical fiber 502.

[0039] Figure 7 shows the direction of signal input and output for the optical fiber branching and switching device 600 according to Embodiment 2. As shown in Figure 7, the fifth optical fiber 505 has a line through which a signal is input from the second optical fiber 502 and output to the first optical fiber 501. Multiple fifth optical fibers 505 transmit signals in only one direction. The sixth optical fiber 506 has a line through which a signal is input from the first optical fiber 501 and output to the third optical fiber 503. Multiple sixth optical fibers 506 transmit signals in only one direction. The seventh optical fiber 507 has a line through which a signal is input from the fourth optical fiber 504 and output to the second optical fiber 502. Multiple seventh optical fibers 507 transmit signals in only one direction.

[0040] With this configuration, the first optical fiber 501, which is a multicore fiber, can transmit both transmit and receive signals. The second optical fiber 502, also a multicore fiber, can transmit both transmit and receive signals. Furthermore, the third optical fiber 503, also a multicore fiber, can transmit both transmit and receive signals.

[0041] Figure 8 shows the direction of signal input and output for the optical fiber branching and switching device 600 according to Embodiment 2. As shown in Figure 8, the plurality of fifth optical fibers 505 include lines through which a signal is input from the first optical fiber 501 and output to the second optical fiber 502, and lines through which a signal is input from the second optical fiber 502 and output to the first optical fiber 501. The plurality of fifth optical fibers 505 transmit signals bidirectionally. The plurality of sixth optical fibers 506 include lines through which a signal is input from the first optical fiber 501 and output to the third optical fiber 503, and lines through which a signal is input from the third optical fiber 503 and output to the first optical fiber 501. The plurality of sixth optical fibers 506 transmit signals bidirectionally. The plurality of seventh optical fibers 507 include lines through which a signal is input from the second optical fiber 502 and output to the fourth optical fiber 504, and lines through which a signal is input from the fourth optical fiber 504 and output to the second optical fiber 502. Multiple seventh optical fibers 507 transmit signals bidirectionally. The line from which the signal of the sixth optical fiber 506 enters from the first optical fiber 501 and exits from the third optical fiber 503 is connected to the line from which the signal of the seventh optical fiber 507 enters from the fourth optical fiber 504 and exits from the second optical fiber 502. This connection is made via the first switching device 201 and the second switching device 202. The line from which the signal of the sixth optical fiber 506 enters from the third optical fiber 503 and exits from the first optical fiber 501 is connected to the line from which the signal of the seventh optical fiber 507 enters from the second optical fiber 502 and exits from the fourth optical fiber 504. This connection is made via the first switching device 201 and the second switching device 202.

[0042] With this configuration, the first optical fiber 501, which is a multicore fiber, can transmit and receive signals. The second optical fiber 502, also a multicore fiber, can transmit and receive signals. Furthermore, the third optical fiber 503, also a multicore fiber, can transmit and receive signals. And finally, the fourth optical fiber 504, also a multicore fiber, can transmit and receive signals. (Description of the optical fiber branching and switching device according to Embodiment 3) Figures 9 and 10 are schematic diagrams of the optical fiber branching and switching device according to Embodiment 3. The optical fiber branching and switching device according to Embodiment 3 will be described with reference to Figures 9 and 10.

[0043] Referring to Figure 9, the optical fiber branching and switching device 900 according to Embodiment 2 comprises a first optical fiber 901, a second optical fiber 902, a third optical fiber 903, a fourth optical fiber 904, a first switching device 911, and a second switching device 912.

[0044] The first optical fiber 901 is connected to the third optical fiber 903 via the optical fiber branching and switching device 900. The second optical fiber 902 is connected to the fourth optical fiber 904 via the optical fiber branching and switching device 900.

[0045] The first optical fiber 901 has a first set of multiple cores. The second optical fiber 902 has a second set of multiple cores. The third optical fiber 903 has a third set of multiple cores. The fourth optical fiber 904 has a fourth set of multiple cores. The first set of multiple cores is connected to the third set of multiple cores. The second set of multiple cores is connected to the fourth set of multiple cores. Also, the number of the first set of multiple cores is equal to the number of the second set of multiple cores. Preferably, the number of the first set of multiple cores is four or more.

[0046] In the optical fiber branching and switching device 900, the first optical fiber 901 is connected to a plurality of second optical fibers 902 via the first switching device 911 and the second switching device 912.

[0047] By using such an optical fiber branching and switching device 900, the multicore fiber of the first optical fiber 901 can be connected to the multicore fiber of the second optical fiber 902.

[0048] Figure 10 shows the direction of signal incidence and emission in the optical fiber branching and switching device 900 according to Embodiment 3. As shown in Figure 10, the first plurality of cores of the first optical fiber 901 are provided with lines for signal incidence to and emission from the optical fiber branching and switching device. The second plurality of cores of the second optical fiber 902 are provided with lines for signal incidence to and emission from the optical fiber branching and switching device. The third plurality of cores of the third optical fiber 903 are provided with lines for signal incidence to and emission from the optical fiber branching and switching device. The fourth plurality of cores of the fourth optical fiber 904 are provided with lines for signal incidence to and emission from the optical fiber branching and switching device.

[0049] The lines through which the signals from the first set of cores enter the optical fiber branching and switching device are connected to the lines through which the signals from the second set of cores exit the optical fiber branching and switching device. Similarly, the lines through which the signals from the first set of cores exit the optical fiber branching and switching device are connected to the lines through which the signals from the second set of cores exit the optical fiber branching and switching device. This connection is made via the first switching device 911 and the second switching device 912.

[0050] With this configuration, the first optical fiber 901, which is a multicore fiber, can transmit and receive signals. The second optical fiber 902, also a multicore fiber, can transmit and receive signals. Furthermore, the third optical fiber 903, also a multicore fiber, can transmit and receive signals. And finally, the fourth optical fiber 904, also a multicore fiber, can transmit and receive signals.

[0051] (Description of the optical fiber branching and switching device according to Embodiment 4) Figures 11 to 13 are schematic diagrams of the optical fiber branching and switching device according to Embodiment 4. The optical fiber branching and switching device according to Embodiment 4 will be described with reference to Figures 11 to 13.

[0052] Referring to Figure 11, the optical fiber branching and switching device 1100 according to Embodiment 4 comprises a first optical fiber 1101, a second optical fiber 1102, a third optical fiber 1103, a fourth optical fiber 1104, a fifth optical fiber 1105, a sixth optical fiber 1106, a seventh optical fiber 1107, an eighth optical fiber 1108, a plurality of ninth optical fibers 1109, a plurality of tenth optical fibers 1110, a plurality of eleventh optical fibers 1111, a plurality of twelfth optical fibers 1112, a first switching device 1121, a second switching device 1122, a third switching device 1123, and a fourth switching device 1124.

[0053] The first optical fiber 1101 is connected via the optical fiber branching and switching device 1100 using the sixth optical fiber 1106 and multiple ninth optical fibers 1109. The second optical fiber 1102 is connected via the optical fiber branching and switching device 1100 using the fifth optical fiber 1105 and multiple tenth optical fibers 1110. The third optical fiber 1103 is connected via the optical fiber branching and switching device 1100 using the seventh optical fiber 1107 and multiple eleventh optical fibers 1111. The fourth optical fiber 1104 is connected via the optical fiber branching and switching device 1100 using the eighth optical fiber 1108 and multiple twelfth optical fibers 1112.

[0054] The first optical fiber 1101 comprises a plurality of first cores. The plurality of cores of the first optical fiber 1101 are fanned in and fanned out into a plurality of ninth optical fibers 1109 within the optical fiber branching and switching device 1100, and then separated.

[0055] The second optical fiber 1102 has a second set of cores. The multiple cores of the second optical fiber 1102 are fanned in and fanned out into a plurality of tenth optical fibers 1110 within the optical fiber branching and switching device 1100, and then separated.

[0056] The third optical fiber 1103 has a third set of cores. The multiple cores of the third optical fiber 1103 are fanned in and fanned out into a plurality of eleventh optical fibers 1111 within the optical fiber branching and switching device 1100, and then separated.

[0057] The fourth optical fiber 1104 has a fourth set of cores. The multiple cores of the fourth optical fiber 1104 are fanned in and fanned out into a plurality of twelfth optical fibers 1112 within the optical fiber branching and switching device 1100, and then separated.

[0058] The fifth optical fiber 1105 has a fifth set of cores. The multiple cores of the fifth optical fiber 1105 are fanned in and fanned out into a set of tenth optical fibers 1110 within the optical fiber branching and switching device 1100, and then separated.

[0059] The sixth optical fiber 1106 has a sixth set of cores. The multiple cores of the sixth optical fiber 1106 are fanned in and fanned out into a plurality of ninth optical fibers 1109 within the optical fiber branching and switching device 1100, and then separated.

[0060] The seventh optical fiber 1107 has seven cores. The multiple cores of the seventh optical fiber 1107 are fanned in and fanned out into multiple eleventh optical fibers 1111 within the optical fiber branching and switching device 1100, and then separated.

[0061] The eighth optical fiber 1108 has eighth multiple cores. The multiple cores of the eighth optical fiber 1108 are fanned in and fanned out into multiple twelfth optical fibers 1112 within the optical fiber branching and switching device 1100, and then separated.

[0062] In the optical fiber branching and switching device 1100, multiple ninth optical fibers 1109 are connected to multiple eleventh optical fibers 1111 via the first switching device 1121 and the second switching device 1122. Therefore, it is preferable that the number of cores in the first optical fiber 1101 is equal to the number of cores in the third optical fiber 1103. In the optical fiber branching and switching device 1100, multiple tenth optical fibers 1110 are connected to multiple twelfth optical fibers 1112 via the third switching device 1123 and the fourth switching device 1124. Therefore, it is preferable that the number of cores in the second optical fiber 1102 is equal to the number of cores in the fourth optical fiber.

[0063] By using such an optical fiber branching and switching device 1100, the multicore fiber of the first optical fiber 1101 can be connected to the multicore fiber of the third optical fiber 1103. In addition, the multicore fiber of the second optical fiber 1102 can be connected to the multicore fiber of the fourth optical fiber 1104.

[0064] Figure 12 shows the direction of signal input and output for the optical fiber branching and switching device 1100 according to Embodiment 4. As shown in Figure 12, the ninth optical fiber 1109 has a line through which a signal is input from the sixth optical fiber 1106 and output to the first optical fiber 1101. Multiple ninth optical fibers 1109 transmit signals in only one direction. The tenth optical fiber 1110 has a line through which a signal is input from the second optical fiber 1102 and output to the fifth optical fiber 1105. Multiple tenth optical fibers 1110 transmit signals in only one direction. The eleventh optical fiber 1111 has a line through which a signal is input from the third optical fiber 1103 and output to the seventh optical fiber 1107. Multiple eleventh optical fibers 1111 transmit signals in only one direction. The twelfth optical fiber 1112 has a line through which a signal is input from the eighth optical fiber 1108 and output to the fourth optical fiber 1104. The multiple 12th optical fibers 1112 transmit signals in only one direction.

[0065] With this configuration, signals can be transmitted from the third optical fiber 1103 to the first optical fiber 1101. Furthermore, signals can be transmitted from the second optical fiber 1102 to the fourth optical fiber 1104.

[0066] Figure 13 shows the direction of signal incidence and emission for the optical fiber branching and switching device 1100 according to Embodiment 4. As shown in Figure 13, the plurality of ninth optical fibers 1109 include lines through which the signal is incident from the first optical fiber 1101 and emitted from the sixth optical fiber 1106, and lines through which the signal is incident from the sixth optical fiber 1106 and emitted from the first optical fiber 1101. The plurality of ninth optical fibers 1109 transmit signals bidirectionally. The plurality of tenth optical fibers 1110 include lines through which the signal is incident from the second optical fiber 1102 and emitted from the fifth optical fiber 1105, and lines through which the signal is incident from the fifth optical fiber 1105 and emitted from the second optical fiber 1102. The plurality of tenth optical fibers 1110 transmit signals bidirectionally. Multiple eleventh optical fibers 1111 each include lines through which a signal enters from the third optical fiber 1103 and exits to the seventh optical fiber 1107, and lines through which a signal enters from the seventh optical fiber 1107 and exits to the third optical fiber 1103. Multiple eleventh optical fibers 1111 transmit signals bidirectionally. Multiple twelfth optical fibers 1112 each include lines through which a signal enters from the fourth optical fiber 1104 and exits to the eighth optical fiber 1108, and lines through which a signal enters from the eighth optical fiber 1108 and exits to the fourth optical fiber 1104. Multiple twelfth optical fibers 1112 transmit signals bidirectionally.

[0067] Then, the signal from the ninth optical fiber 1109, which enters from the first optical fiber 1101 and exits to the sixth optical fiber 1106, is connected to the signal from the eleventh optical fiber 1111, which enters from the seventh optical fiber 1107 and exits to the third optical fiber 1103. This connection is made via the first switching device 1121 and the second switching device 1122. The signal from the ninth optical fiber 1109, which enters from the sixth optical fiber 1106 and exits to the first optical fiber 1101, is connected to the signal from the eleventh optical fiber 1111, which enters from the third optical fiber 1103 and exits to the seventh optical fiber 1107. This connection is made via the first switching device 1121 and the second switching device 1122.

[0068] With this configuration, the first optical fiber 1101, which is a multicore fiber, can transmit and receive signals. The third optical fiber 1103, which is also a multicore fiber, can transmit and receive signals. Furthermore, the sixth optical fiber 1106, which is also a multicore fiber, can transmit and receive signals. Furthermore, the seventh optical fiber 1107, which is also a multicore fiber, can transmit and receive signals.

[0069] Then, the signal from the 10th optical fiber 1110, which enters from the 2nd optical fiber 1102 and exits to the 5th optical fiber 1105, is connected to the signal from the 12th optical fiber 1112, which enters from the 8th optical fiber 1108 and exits to the 4th optical fiber 1104. This connection is made via the 3rd switching device 1123 and the 4th switching device 1124. The signal from the 10th optical fiber 1110, which enters from the 5th optical fiber 1105 and exits to the 2nd optical fiber 1102, is connected to the signal from the 12th optical fiber 1112, which enters from the 4th optical fiber 1104 and exits to the 8th optical fiber 1108. This connection is made via the 3rd switching device 1123 and the 4th switching device 1124.

[0070] With this configuration, the second optical fiber 1102, which is a multicore fiber, can transmit and receive signals. The fourth optical fiber 1104, which is also a multicore fiber, can transmit and receive signals. Furthermore, the fifth optical fiber 1105, which is also a multicore fiber, can transmit and receive signals. Furthermore, the eighth optical fiber 1108, which is also a multicore fiber, can transmit and receive signals.

[0071] (Description of the optical fiber branching and switching device according to Embodiment 5) Figure 14 is a schematic diagram of an optical fiber branching and switching device according to Embodiment 5. Figures 15 to 17 are schematic diagrams of another optical fiber branching and switching device according to Embodiment 5. The optical fiber branching and switching device according to Embodiment 5 will be described with reference to Figures 14 to 17.

[0072] Referring to Figure 14, the optical fiber branching and switching device 1400 according to Embodiment 5 comprises a first optical fiber 1401, a second optical fiber 1402, a third optical fiber 1403, a fourth optical fiber 1404, a fifth optical fiber 1405, a sixth optical fiber 1406, a seventh optical fiber 1407, a plurality of eighth optical fibers 1408, a plurality of ninth optical fibers 1409, a plurality of tenth optical fibers 1410, and a plurality of eleventh optical fibers 1411.

[0073] The first optical fiber 1401 is connected via an optical fiber branching and switching device 1400 using the fifth optical fiber 1405 and multiple eighth optical fibers 1408. The second optical fiber 1402 is connected via an optical fiber branching and switching device 1400 using the fifth optical fiber 1405 and multiple ninth optical fibers 1409. The third optical fiber 1403 is connected via an optical fiber branching and switching device 1400 using the sixth optical fiber 1406 and multiple tenth optical fibers. The fourth optical fiber 1404 is connected via an optical fiber branching and switching device 1400 using the seventh optical fiber 1407 and multiple eleventh optical fibers 1411.

[0074] The first optical fiber 1401 comprises a plurality of first cores. The plurality of cores of the first optical fiber 1401 are fanned in and fanned out into a plurality of eighth optical fibers 1408 within the optical fiber branching and switching device 1400, and then separated.

[0075] The second optical fiber 1402 comprises a second set of cores. The multiple cores of the second optical fiber 1402 are fanned in and fanned out into a set of ninth optical fibers 1409 within the optical fiber branching and switching device 1400, and then separated.

[0076] The third optical fiber 1403 has a third set of cores. The multiple cores of the third optical fiber 1403 are fanned in and fanned out into a set of tenth optical fibers 1410 within the optical fiber branching and switching device 1400, and then separated.

[0077] The fourth optical fiber 1404 has a fourth set of cores. The multiple cores of the fourth optical fiber 1404 are fanned in and fanned out into a plurality of eleventh optical fibers 1411 within the optical fiber branching and switching device 1400, and then separated.

[0078] The fifth optical fiber 1405 has a fifth set of cores. The multiple cores of the fifth optical fiber 1405 are fanned in and fanned out into a plurality of eighth optical fibers 1408 and a plurality of ninth optical fibers 1409 within the optical fiber branching and switching device 1400, and then separated.

[0079] The sixth optical fiber 1406 has a sixth set of cores. The multiple cores of the sixth optical fiber 1406 are fanned in and fanned out into a plurality of tenth optical fibers 1410 within the optical fiber branching and switching device 1400, and then separated.

[0080] The seventh optical fiber 1407 has seven multiple cores. The multiple cores of the seventh optical fiber 1407 are fanned in and fanned out into multiple eleventh optical fibers 1411 within the optical fiber branching and switching device 1400 and separated.

[0081] By using such an optical fiber branching and switching device 1400, it is possible to branch and switch a multicore fiber to another multicore fiber.

[0082] Referring to Figure 15, the optical fiber branching and switching device 1500 according to Embodiment 5 further comprises a first switching device 1501, a second switching device 1502, a third switching device 1503, and a fourth switching device 1504, in addition to the configuration of the optical fiber branching and switching device 1400. In the optical fiber branching and switching device 1500, multiple eighth optical fibers 1408 are connected to multiple tenth optical fibers 1410 via the first switching device 1501 and the second switching device 1502. Multiple ninth optical fibers 1409 are connected to multiple eleventh optical fibers 1411 via the third switching device 1503 and the fourth switching device 1504.

[0083] By using such an optical fiber branching and switching device 1400, the multicore fiber of the first optical fiber 1401 can be connected to the multicore fiber of the third optical fiber 1403. In addition, the multicore fiber of the second optical fiber 1402 can be connected to the multicore fiber of the fourth optical fiber 1404.

[0084] Figure 16 shows the direction of signal input and output for the optical fiber branching and switching device 1500 according to Embodiment 5. As shown in Figure 16, the eighth optical fiber 1408 has a line through which a signal is input from the fifth optical fiber 1405 and output to the first optical fiber 1401. Multiple eighth optical fibers 1408 transmit signals in only one direction. The ninth optical fiber 1409 has a line through which a signal is input from the second optical fiber 1402 and output to the fifth optical fiber 1405. Multiple ninth optical fibers 1409 transmit signals in only one direction. The tenth optical fiber 1410 has a line through which a signal is input from the third optical fiber 1403 and output to the sixth optical fiber 1406. Multiple tenth optical fibers 1410 transmit signals in only one direction. The eleventh optical fiber 1411 has a line through which a signal is input from the seventh optical fiber 1407 and output to the fourth optical fiber 1404. The multiple 11th optical fibers 1411 transmit signals in only one direction.

[0085] With this configuration, signals can be transmitted from the third optical fiber 1403 to the first optical fiber 1401. Furthermore, signals can be transmitted from the second optical fiber 1402 to the fourth optical fiber 1404. Additionally, the fifth optical fiber 1405 can transmit and receive signals.

[0086] Figure 17 shows the direction of signal incidence and emission for the optical fiber branching and switching device 1500 according to Embodiment 5. As shown in Figure 17, the multiple eighth optical fibers 1408 include lines through which signals are incident from the first optical fiber 1401 and emitted to the fifth optical fiber 1405, and lines through which signals are incident from the fifth optical fiber 1405 and emitted to the first optical fiber 1401. The multiple eighth optical fibers 1408 transmit signals bidirectionally. The multiple ninth optical fibers 1409 include lines through which signals are incident from the second optical fiber 1402 and emitted to the fifth optical fiber 1405, and lines through which signals are incident from the fifth optical fiber 1405 and emitted to the second optical fiber 1402. The multiple ninth optical fibers 1409 transmit signals bidirectionally. Multiple tenth optical fibers 1410 include lines through which a signal enters from the third optical fiber 1403 and exits to the sixth optical fiber 1406, and lines through which a signal enters from the sixth optical fiber 1406 and exits to the third optical fiber 1403. Multiple tenth optical fibers 1410 transmit signals bidirectionally. Multiple eleventh optical fibers 1411 include lines through which a signal enters from the fourth optical fiber 1404 and exits to the seventh optical fiber 1407, and lines through which a signal enters from the seventh optical fiber 1407 and exits to the fourth optical fiber 1404. Multiple eleventh optical fibers 1411 transmit signals bidirectionally.

[0087] Then, the signal from the eighth optical fiber 1408, which enters from the first optical fiber 1401 and exits to the fifth optical fiber 1405, is connected to the signal from the tenth optical fiber 1410, which enters from the sixth optical fiber 1406 and exits to the third optical fiber 1403. This connection is made via the first switching device 1501 and the second switching device 1502. The signal from the eighth optical fiber 1408, which enters from the fifth optical fiber 1405 and exits to the first optical fiber 1401, is connected to the signal from the tenth optical fiber 1410, which enters from the third optical fiber 1403 and exits to the sixth optical fiber 1406. This connection is made via the first switching device 1501 and the second switching device 1502.

[0088] With this configuration, the first optical fiber 1401, which is a multicore fiber, can transmit and receive signals. The third optical fiber 1403, which is also a multicore fiber, can transmit and receive signals. Furthermore, the fifth optical fiber 1405, which is also a multicore fiber, can transmit and receive signals. And finally, the sixth optical fiber 1406, which is also a multicore fiber, can transmit and receive signals.

[0089] Then, the signal from the ninth optical fiber 1409, which enters from the second optical fiber 1402 and exits to the fifth optical fiber 1405, is connected to the signal from the eleventh optical fiber 1411, which enters from the seventh optical fiber 1407 and exits to the fourth optical fiber 1404. This connection is made via the third switching device 1503 and the fourth switching device 1504. The signal from the ninth optical fiber 1409, which enters from the fifth optical fiber 1405 and exits to the second optical fiber 1402, is connected to the signal from the eleventh optical fiber 1411, which enters from the fourth optical fiber 1404 and exits to the seventh optical fiber 1407. This connection is made via the third switching device 1503 and the fourth switching device 1504.

[0090] With this configuration, the second optical fiber 1402, which is a multicore fiber, can transmit the transmit and receive signals. The fourth optical fiber 1404, which is also a multicore fiber, can transmit the transmit and receive signals. Furthermore, the fifth optical fiber 1405, which is also a multicore fiber, can transmit the transmit and receive signals. Furthermore, the seventh optical fiber 1407, which is also a multicore fiber, can transmit the transmit and receive signals.

[0091] (Description of the optical fiber branching and switching device according to Embodiment 6) Figures 18 to 20 are schematic diagrams of the optical fiber branching and switching device according to Embodiment 6. The optical fiber branching and switching device according to Embodiment 6 will be described with reference to Figures 18 to 20.

[0092] Referring to Figure 18, the optical fiber branching and switching device 1800 according to Embodiment 6 comprises a first optical fiber 1801, a second optical fiber 1802, a third optical fiber 1803, a fourth optical fiber 1804, a plurality of fifth optical fibers 1805, a plurality of sixth optical fibers 1806, a plurality of seventh optical fibers 1807, a plurality of eighth optical fibers 1808, a first switching device 1811, and a second switching device 1812.

[0093] The first optical fiber 1801 is connected to the third optical fiber 1803 via an optical fiber branching and switching device 1800 using a plurality of fifth optical fibers 1805 and a plurality of sixth optical fibers 1806. The second optical fiber 1802 is connected to the fourth optical fiber 1804 via an optical fiber branching and switching device 1800 using a plurality of seventh optical fibers 1807 and a plurality of eighth optical fibers.

[0094] The first optical fiber 1801 comprises a plurality of first cores. The plurality of cores of the first optical fiber 1801 are fanned in and fanned out into a plurality of fifth optical fibers 1805 and a plurality of sixth optical fibers 1806 within the optical fiber branching and switching device 1800, and are separated.

[0095] The second optical fiber 1802 comprises a second set of cores. The multiple cores of the second optical fiber 1802 are fanned in and fanned out into a set of seventh optical fibers 1807 and a set of eighth optical fibers 1808 within the optical fiber branching and switching device 1800, and are separated.

[0096] The third optical fiber 1803 has a third set of cores. The multiple cores of the third optical fiber 1803 are fanned in and fanned out into a set of fifth optical fibers 1805 and a set of sixth optical fibers 1806 within the optical fiber branching and switching device 1800, and are separated.

[0097] The fourth optical fiber 1804 has a fourth set of cores. The multiple cores of the fourth optical fiber 1804 are fanned in and fanned out into a plurality of seventh optical fibers 1807 and a plurality of eighth optical fibers 1808 within the optical fiber branching and switching device 1800, and are separated.

[0098] In the optical fiber branching and switching device 1800, multiple fifth optical fibers 1805 are connected to multiple seventh optical fibers 1807 via the first switching device 1811 and the second switching device 1812.

[0099] By using such an optical fiber branching and switching device 1800, the multicore fiber of the first optical fiber 1801 can be connected to the multicore fiber of the second optical fiber 1802.

[0100] Figure 19 shows the direction of signal incidence and emission for the optical fiber branching and switching device 1800 according to Embodiment 6. As shown in Figure 19, the fifth optical fiber 1805 has a line through which a signal is incident from the third optical fiber 1803 and emitted from the first optical fiber 1801. Multiple fifth optical fibers 1805 transmit signals in only one direction. The sixth optical fiber 1806 has a line through which a signal is incident from the first optical fiber 1801 and emitted from the third optical fiber 1803. Multiple sixth optical fibers 1806 transmit signals in only one direction. The seventh optical fiber 1807 has a line through which a signal is incident from the second optical fiber 1802 and emitted from the fourth optical fiber 1804. Multiple seventh optical fibers 1807 transmit signals in only one direction. The eighth optical fiber 1808 has a line through which a signal is incident from the fourth optical fiber 1804 and emitted from the second optical fiber 1802. The multiple eighth optical fibers 1808 transmit signals in only one direction.

[0101] With this configuration, signals can be transmitted from the second optical fiber 1802 to the first optical fiber 1801.

[0102] Figure 20 shows the direction of signal incidence and emission for the optical fiber branching and switching device 1800 according to Embodiment 6. As shown in Figure 20, the plurality of fifth optical fibers 1805 include lines through which the signal is incident from the first optical fiber 1801 and emitted from the third optical fiber 1803, and lines through which the signal is incident from the third optical fiber 1803 and emitted from the first optical fiber 1801. The plurality of fifth optical fibers 1805 transmit signals bidirectionally. The plurality of sixth optical fibers 1806 include lines through which the signal is incident from the first optical fiber 1801 and emitted from the third optical fiber 1803, and lines through which the signal is incident from the third optical fiber 1803 and emitted from the first optical fiber 1801. The plurality of sixth optical fibers 1806 transmit signals bidirectionally. Multiple seventh optical fibers 1807 include lines through which a signal enters from the second optical fiber 1802 and exits to the fourth optical fiber 1804, and lines through which a signal enters from the fourth optical fiber 1804 and exits to the second optical fiber 1802. Multiple seventh optical fibers 1807 transmit signals bidirectionally. Multiple eighth optical fibers 1808 include lines through which a signal enters from the second optical fiber 1802 and exits to the fourth optical fiber 1804, and lines through which a signal enters from the fourth optical fiber 1804 and exits to the second optical fiber 1802. Multiple eighth optical fibers 1808 transmit signals bidirectionally.

[0103] Then, the signal from the fifth optical fiber 1805, which enters from the first optical fiber 1801 and exits to the third optical fiber 1803, is connected to the signal from the seventh optical fiber 1807, which enters from the fourth optical fiber 1804 and exits to the second optical fiber 1802. This connection is made via the first switching device 1811 and the second switching device 1812. The signal from the fifth optical fiber 1805, which enters from the third optical fiber 1803 and exits to the first optical fiber 1801, is connected to the signal from the seventh optical fiber 1807, which enters from the second optical fiber 1802 and exits to the fourth optical fiber 1804. This connection is made via the first switching device 1811 and the second switching device 1812.

[0104] With this configuration, the first optical fiber 1801, which is a multicore fiber, can transmit and receive signals. The second optical fiber 1802, which is also a multicore fiber, can transmit and receive signals. Furthermore, the third optical fiber 1803, which is also a multicore fiber, can transmit and receive signals. Furthermore, the fourth optical fiber 1804, which is also a multicore fiber, can transmit and receive signals.

[0105] (Description of the optical fiber branching and switching device according to Embodiment 7) Figure 21 is a schematic diagram of an optical fiber branching and switching device according to Embodiment 7. Figures 22 to 25 are schematic diagrams of other optical fiber branching and switching devices according to Embodiment 7. The optical fiber branching and switching device according to Embodiment 7 will be described with reference to Figures 21 to 25.

[0106] Referring to Figure 21, the optical fiber branching and switching device 2100 according to Embodiment 7 comprises a first optical fiber 2101, a second optical fiber 2102, a third optical fiber 2103, a plurality of fourth optical fibers 2104, a plurality of fifth optical fibers 2105, a sixth optical fiber 2106, and a seventh optical fiber 2107.

[0107] The first optical fiber 2101 is connected to the second optical fiber 2102 via an optical fiber branching and switching device 2100 using a plurality of fourth optical fibers 2104. The first optical fiber 2101 is connected to the third optical fiber 2103 via an optical fiber branching and switching device 2100 using a plurality of fifth optical fibers 2105. The second optical fiber 2102 is connected to the sixth optical fiber 2106 via an optical fiber branching and switching device 2100. The second optical fiber 2102 is connected to the seventh optical fiber 2107 via an optical fiber branching and switching device 2100.

[0108] The first optical fiber 2101 comprises a plurality of first cores. The plurality of cores of the first optical fiber 2101 are fanned in and fanned out into a plurality of fourth optical fibers 2104 and a plurality of fifth optical fibers 2105 within the optical fiber branching and switching device 2100, and then separated.

[0109] The second optical fiber 2102 comprises a second set of cores. The multiple cores of the second optical fiber 2102 are fanned in and fanned out into a set of fourth optical fibers 2104, sixth optical fiber 2106, and seventh optical fiber 2107 within the optical fiber branching and switching device 2100, and are separated.

[0110] The third optical fiber 103 has a third set of cores. The multiple cores of the third optical fiber 2103 are fanned in and fanned out into a set of fifth optical fibers 2105 within the optical fiber branching and switching device 2100.

[0111] By using such an optical fiber branching and switching device 2100, it is possible to branch and switch a multicore fiber to another multicore fiber.

[0112] Referring to Figure 22, the optical fiber branching and switching device 2200 according to Embodiment 7 further comprises a first switching device 2201, a second switching device 2202, a third switching device 2203, and a fourth switching device 2204, in addition to the configuration of the optical fiber branching and switching device 2100. In the optical fiber branching and switching device 2200, one of the fifth optical fibers 2105 is connected to the sixth optical fiber 2106 via the first switching device 2201 and the second switching device 2202. Also, the other of the fifth optical fibers 2105 is connected to the seventh optical fiber 2107 via the third switching device 2203 and the fourth switching device 2204.

[0113] By using such an optical fiber branching and switching device 200, the multicore fiber of the first optical fiber 2101 can be connected to the multicore fiber of the second optical fiber 2102.

[0114] Figure 23 shows the direction of signal input and output for the optical fiber branching and switching device 2200 according to Embodiment 7. As shown in Figure 23, the fourth optical fiber 2104 has a line through which a signal is input from the second optical fiber 2102 and output to the first optical fiber 2101. Multiple fourth optical fibers 2104 transmit signals in only one direction. The fifth optical fiber 2105 has a line through which a signal is input from the first optical fiber 2101 and output to the third optical fiber 2103. Multiple fifth optical fibers 2105 transmit signals in only one direction. The sixth optical fiber 2106 has a line through which a signal is output to the second optical fiber 2102. The seventh optical fiber 2107 has a line through which a signal is output to the second optical fiber 2102.

[0115] With this configuration, the first optical fiber 2101, which is a multicore fiber, can transmit both the transmit and receive signals. The second optical fiber 2102, which is also a multicore fiber, can also transmit both the transmit and receive signals.

[0116] Figure 24 shows the direction of signal incidence and emission for the optical fiber branching and switching device 2200 according to Embodiment 7. As shown in Figure 24, the fourth optical fiber 2104 has a line through which the signal is incident from the first optical fiber 2101 and emitted from the second optical fiber 2102. Multiple fourth optical fibers 2104 transmit signals in only one direction. The fifth optical fiber 2105 has a line through which the signal is incident from the third optical fiber 2103 and emitted from the first optical fiber 2101. Multiple fifth optical fibers 2105 transmit signals in only one direction. The sixth optical fiber 2106 has a line through which the signal is incident from the second optical fiber 2102. The seventh optical fiber 2107 has a line through which the signal is incident from the second optical fiber 2102.

[0117] With this configuration, the first optical fiber 2101, which is a multicore fiber, can transmit both the transmit and receive signals. The second optical fiber 2102, which is also a multicore fiber, can also transmit both the transmit and receive signals.

[0118] Figure 25 shows the direction of signal incidence and emission for the optical fiber branching and switching device 2200 according to Embodiment 7. As shown in Figure 25, the plurality of fourth optical fibers 2104 include lines through which the signal is incident from the first optical fiber 2101 and emitted from the second optical fiber 2102, and lines through which the signal is incident from the second optical fiber 2102 and emitted from the first optical fiber 2101. The plurality of fourth optical fibers 2104 transmit signals bidirectionally. The plurality of fifth optical fibers 2105 include lines through which the signal is incident from the first optical fiber 2101 and emitted from the third optical fiber 2103, and lines through which the signal is incident from the third optical fiber 2103 and emitted from the first optical fiber 2101. The plurality of fifth optical fibers 2105 transmit signals bidirectionally. The sixth optical fiber 2106 includes a line through which the signal is emitted from the second optical fiber 2102. The seventh optical fiber 2107 includes a line through which a signal enters the second optical fiber. The line through which the signal of the fifth optical fiber 2105 enters from the first optical fiber 2101 and exits from the third optical fiber 2103 is connected to the seventh optical fiber 2107. This connection is made via the third switching device 2203 and the fourth switching device 2204. The line through which the signal of the fifth optical fiber 2105 enters from the third optical fiber 2103 and exits from the first optical fiber 2101 is connected to the sixth optical fiber 2106. This connection is made via the first switching device 2201 and the second switching device 2202.

[0119] With this configuration, the first optical fiber 2101, which is a multicore fiber, can transmit both transmit and receive signals. The second optical fiber 2102, also a multicore fiber, can transmit both transmit and receive signals. Furthermore, the third optical fiber 2103, also a multicore fiber, can transmit both transmit and receive signals.

[0120] As described above, the optical fiber branching and switching devices according to Embodiments 1 to 7 can branch multiple optical fibers using a multicore fiber fan-in / fan-out device. However, the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention.

[0121] Some or all of the above embodiments may be described as follows, but are not limited to the following: (Note 1) It comprises a first optical fiber, a second optical fiber, a third optical fiber, a plurality of fourth optical fibers, a plurality of fifth optical fibers, and a plurality of sixth optical fibers. The first optical fiber is connected to the second optical fiber and a plurality of the fourth optical fibers, The first optical fiber is connected to the third optical fiber and a plurality of the fifth optical fibers, An optical fiber branching and switching device in which the second optical fiber is connected to the third optical fiber and a plurality of the sixth optical fibers. (Note 2) The first optical fiber comprises a first plurality of cores, The second optical fiber comprises a second plurality of cores, The third optical fiber comprises a third number of cores, The first plurality of cores are separated into a plurality of fourth optical fibers and a plurality of fifth optical fibers. The second plurality of cores are separated into a plurality of the fourth optical fibers and a plurality of the sixth optical fibers, The optical fiber branching and switching device according to Appendix 1, wherein the third plurality of cores are separated into a plurality of fifth optical fibers and a plurality of sixth optical fibers. (Note 3) The optical fiber branching and switching device described in Appendix 2, wherein the first optical fiber is fanned in and fanned out to a plurality of fourth optical fibers and a plurality of fifth optical fibers, the second optical fiber is fanned in and fanned out to a plurality of fourth optical fibers and a plurality of sixth optical fibers, and the third optical fiber is fanned in and fanned out to a plurality of fifth optical fibers and a plurality of sixth optical fibers. (Note 4) It comprises a first switching device and a second switching device, The optical fiber branching and switching device according to Appendix 1, wherein a plurality of the fifth optical fibers are connected to a plurality of the sixth optical fibers via the first switching device and the second switching device. (Note 5) The fourth optical fiber comprises a line that enters from the second optical fiber and exits from the first optical fiber. The fifth optical fiber comprises a line that enters from the first optical fiber and exits from the third optical fiber. The optical fiber branching and switching device according to Appendix 4, wherein the sixth optical fiber comprises a line that enters from the third optical fiber and exits from the second optical fiber. (Note 6) The plurality of the aforementioned fourth optical fibers each include at least one line that enters from the first optical fiber and exits from the second optical fiber and one line that enters from the second optical fiber and exits from the first optical fiber. The plurality of fifth optical fibers each include at least one line that enters from the first optical fiber and exits from the third optical fiber, and one line that enters from the third optical fiber and exits from the first optical fiber. The plurality of the aforementioned sixth optical fibers each include at least one line that enters from the second optical fiber and exits from the third optical fiber and one line that enters from the third optical fiber and exits from the second optical fiber. A line entering the fifth optical fiber from the first optical fiber and exiting the third optical fiber is connected to a line entering the sixth optical fiber from the third optical fiber and exiting the second optical fiber. The optical fiber branching and switching device according to Appendix 4, wherein a line entering the fifth optical fiber from the third optical fiber and exiting the first optical fiber is connected to a line entering the sixth optical fiber from the second optical fiber and exiting the third optical fiber. (Note 7) It comprises a first optical fiber, a second optical fiber, a third optical fiber, a fourth optical fiber, a plurality of fifth optical fibers, a plurality of sixth optical fibers, and a plurality of seventh optical fibers. The first optical fiber is connected to the second optical fiber using a plurality of the fifth optical fibers. The first optical fiber is connected to the third optical fiber using a plurality of the sixth optical fibers, An optical fiber branching and switching device in which the second optical fiber is connected to the fourth optical fiber and a plurality of the seventh optical fibers. (Note 8) The first optical fiber comprises a first plurality of cores, The second optical fiber comprises a second plurality of cores, The first plurality of cores are separated into a plurality of fifth optical fibers and a plurality of sixth optical fibers, The optical fiber branching and switching device according to Appendix 7, wherein the second plurality of cores are separated into a plurality of the fifth optical fibers and a plurality of the seventh optical fibers. (Note 9) The optical fiber branching and switching device according to Appendix 7, wherein the first optical fiber is fanned in and out into a plurality of fifth optical fibers and a plurality of sixth optical fibers, the second optical fiber is fanned in and out into a plurality of fifth optical fibers and a plurality of seventh optical fibers, the third optical fiber is fanned in and out into a plurality of sixth optical fibers, and the fourth optical fiber is fanned in and out into a plurality of seventh optical fibers. (Note 10) It comprises a first switching device and a second switching device, The optical fiber branching and switching device according to Appendix 7, wherein a plurality of the sixth optical fibers are connected to a plurality of the seventh optical fibers via the first switching device and the second switching device. (Note 11) The fifth optical fiber comprises a line that enters from the second optical fiber and exits from the first optical fiber. The sixth optical fiber comprises a line that enters from the first optical fiber and exits from the third optical fiber. The optical fiber branching and switching device according to Appendix 10, wherein the seventh optical fiber includes a line that enters from the fourth optical fiber and exits from the second optical fiber. (Note 12) The plurality of the fifth optical fibers each include at least one line that enters from the first optical fiber and exits from the second optical fiber and one line that enters from the second optical fiber and exits from the first optical fiber. The plurality of the sixth optical fibers each include at least one line that enters from the first optical fiber and exits from the third optical fiber and one line that enters from the third optical fiber and exits from the first optical fiber. The plurality of the aforementioned seven optical fibers each include at least one line that enters from the aforementioned second optical fiber and exits from the aforementioned fourth optical fiber, and one line that enters from the aforementioned fourth optical fiber and exits from the aforementioned second optical fiber. The line that enters the sixth optical fiber from the first optical fiber and exits the third optical fiber is connected to the line that enters the seventh optical fiber from the fourth optical fiber and exits the second optical fiber. The optical fiber branching and switching device according to Appendix 10, wherein a line entering the sixth optical fiber from the third optical fiber and exiting the first optical fiber is connected to a line entering the seventh optical fiber from the second optical fiber and exiting the fourth optical fiber. (Note 13) A first optical fiber having a first number of cores, a second optical fiber having a second number of cores, a third optical fiber having a third number of cores, and a fourth optical fiber having a fourth number of cores, It comprises a first switching device and a second switching device, The first plurality of cores are connected to the third plurality of cores, The second plurality of cores are connected to the fourth plurality of cores, An optical fiber branching and switching device in which the first plurality of cores are connected to the second plurality of cores via the first switching device and the second switching device. (Note 14) The optical fiber branching and switching device according to Appendix 13, wherein the number of the first plurality of cores is equal to the number of the second plurality of cores. (Note 15) The optical fiber branching and switching device described in Appendix 14, wherein the number of the first multiple cores is four or more. (Note 16) The first plurality of cores each comprises at least a line that enters and exits the optical fiber branching and switching device, The second plurality of cores each comprises at least a line that enters and exits the optical fiber branching and switching device, The lines that enter the optical fiber branching and switching device of the first plurality of cores are connected to the lines that exit the optical fiber branching and switching device of the second plurality of cores. An optical fiber branching and switching device according to any one of appendices 13 to 15, wherein the lines that emit from the first plurality of cores to the optical fiber branching and switching device are connected to the lines that emit from the second plurality of cores to the optical fiber branching and switching device. (Note 17) The first optical fiber, the second optical fiber, the third optical fiber, the fourth optical fiber, the fifth optical fiber, the sixth optical fiber, the seventh optical fiber, the eighth optical fiber, multiple ninth optical fibers, multiple tenth optical fibers, multiple eleventh optical fibers, multiple twelfth optical fibers, It comprises a first switching device, a second switching device, a third switching device, and a fourth switching device. The first optical fiber is connected to the sixth optical fiber and a plurality of the ninth optical fibers, The second optical fiber is connected to the fifth optical fiber using a plurality of the tenth optical fibers. The third optical fiber is connected to the seventh optical fiber using a plurality of the eleventh optical fibers. The fourth optical fiber is connected to the eighth optical fiber and a plurality of the twelfth optical fibers. Multiple 9 optical fibers are connected to multiple 11 optical fibers via the first and second switching devices. An optical fiber branching and switching device in which a plurality of the 10 optical fibers are connected to a plurality of the 12 optical fibers via the third switching device and the fourth switching device. (Note 18) The number of cores in the first optical fiber is equal to the number of cores in the third optical fiber. The optical fiber branching and switching device described in Appendix 17, wherein the number of cores in the second optical fiber is equal to the number of cores in the fourth optical fiber. (Note 19) The ninth optical fiber is a line that enters from the sixth optical fiber and exits to the first optical fiber. The tenth optical fiber is a line that enters from the second optical fiber and exits from the fifth optical fiber. The 11th optical fiber is a line that enters from the 3rd optical fiber and exits from the 7th optical fiber. The optical fiber branching and switching device according to Appendix 17 or 18, wherein the 12th optical fiber is a line that enters from the 8th optical fiber and exits from the 4th optical fiber. (Note 20) The plurality of ninth optical fibers each include at least one line that enters from the first optical fiber and exits to the sixth optical fiber, and one line that enters from the sixth optical fiber and exits to the first optical fiber. The plurality of the tenth optical fibers each include at least one line that enters from the second optical fiber and exits to the fifth optical fiber, and one line that enters from the fifth optical fiber and exits to the second optical fiber. The plurality of the 11 optical fibers each include at least one line that enters from the third optical fiber and exits from the seventh optical fiber, and one line that enters from the seventh optical fiber and exits from the third optical fiber. The plurality of the aforementioned twelve optical fibers each include at least one line that enters from the fourth optical fiber and exits from the eighth optical fiber, and one line that enters from the eighth optical fiber and exits from the fourth optical fiber. The line that enters the 9th optical fiber from the 1st optical fiber and exits the 6th optical fiber is connected to the line that enters the 11th optical fiber from the 7th optical fiber and exits the 3rd optical fiber. The line that enters the 6th optical fiber of the 9th optical fiber and exits the 1st optical fiber is connected to the line that enters the 3rd optical fiber of the 11th optical fiber and exits the 7th optical fiber. A line entering the 10th optical fiber from the 2nd optical fiber and exiting the 5th optical fiber is connected to a line entering the 12th optical fiber from the 8th optical fiber and exiting the 4th optical fiber. The optical fiber branching and switching device according to Appendix 17 or 18, wherein a line entering the 10th optical fiber from the 5th optical fiber and exiting the 2nd optical fiber is connected to a line entering the 12th optical fiber from the 4th optical fiber and exiting the 8th optical fiber. (Note 21) It comprises a first optical fiber, a second optical fiber, a third optical fiber, a fourth optical fiber, a fifth optical fiber, a sixth optical fiber, a seventh optical fiber, a plurality of eighth optical fibers, a plurality of ninth optical fibers, a plurality of tenth optical fibers, and a plurality of eleventh optical fibers. The first optical fiber is connected to the fifth optical fiber and a plurality of the eighth optical fibers, The second optical fiber is connected to the fifth optical fiber using a plurality of the ninth optical fibers. The third optical fiber is connected to the sixth optical fiber using a plurality of the tenth optical fibers. The aforementioned fourth optical fiber is connected to the aforementioned seventh optical fiber and a plurality of aforementioned eleventh optical fibers in an optical fiber branching and switching device. (Note 22) The fifth optical fiber comprises a first plurality of cores, The optical fiber branching and switching device according to Appendix 21, wherein the first plurality of cores are separated into a plurality of the eighth optical fibers and a plurality of the ninth optical fibers. (Note 23) The optical fiber branching and switching device described in Appendix 21, wherein the fifth optical fiber is fanned in and fanned out to a plurality of eighth optical fibers and a plurality of ninth optical fibers. (Note 24) It comprises a first switching device, a second switching device, a third switching device, and a fourth switching device. Multiple eight optical fibers are connected to multiple ten optical fibers via the first and second switching devices. The optical fiber branching and switching device according to Appendix 21, wherein a plurality of the 9th optical fibers are connected to a plurality of the 11th optical fibers via the third switching device and the fourth switching device. (Note 25) The eighth optical fiber comprises a line that enters from the fifth optical fiber and exits to the first optical fiber. The ninth optical fiber comprises a line that enters from the second optical fiber and exits from the fifth optical fiber. The tenth optical fiber comprises a line that enters from the third optical fiber and exits from the sixth optical fiber. The optical fiber branching and switching device according to Appendix 24, wherein the 11th optical fiber includes a line that enters from the 8th optical fiber and exits from the 4th optical fiber. (Note 26) The plurality of eight optical fibers each include at least one line that enters from the first optical fiber and exits to the fifth optical fiber, and one line that enters from the fifth optical fiber and exits to the first optical fiber. The plurality of the ninth optical fibers each include at least one line that enters from the second optical fiber and exits to the fifth optical fiber, and one line that enters from the fifth optical fiber and exits to the second optical fiber. The plurality of the tenth optical fibers each include at least one line that enters from the third optical fiber and exits from the sixth optical fiber, and one line that enters from the sixth optical fiber and exits from the third optical fiber. The plurality of the 11 optical fibers each include at least one line that enters from the 4 optical fiber and exits from the 7 optical fiber, and one line that enters from the 7 optical fiber and exits from the 4 optical fiber. A line entering the eighth optical fiber from the first optical fiber and exiting the fifth optical fiber is connected to a line entering the tenth optical fiber from the sixth optical fiber and exiting the third optical fiber. A line entering the eighth optical fiber from the fifth optical fiber and exiting the first optical fiber is connected to a line entering the tenth optical fiber from the third optical fiber and exiting the sixth optical fiber. The line that enters the 9th optical fiber from the 2nd optical fiber and exits the 5th optical fiber is connected to the line that enters the 11th optical fiber from the 7th optical fiber and exits the 4th optical fiber. An optical fiber branching and switching device according to any one of the appendices 21 to 25, wherein a line entering the 9th optical fiber from the 5th optical fiber and exiting the 2nd optical fiber is connected to a line entering the 11th optical fiber from the 4th optical fiber and exiting the 7th optical fiber. (Note 27) A first optical fiber, a second optical fiber, a third optical fiber, a fourth optical fiber, multiple fifth optical fibers, multiple sixth optical fibers, multiple seventh optical fibers, multiple eighth optical fibers, It comprises a first switching device and a second switching device, The first optical fiber is connected to the third optical fiber using a plurality of the fifth optical fiber and a plurality of the sixth optical fiber. The aforementioned second optical fiber is connected to the aforementioned fourth optical fiber using a plurality of the aforementioned seventh optical fiber and a plurality of the aforementioned eighth optical fiber. An optical fiber branching and switching device in which a plurality of the fifth optical fibers are connected to a plurality of the seventh optical fibers via the first switching device and the second switching device. (Note 28) The fifth optical fiber is a line that enters from the third optical fiber and exits from the first optical fiber. The optical fiber branching and switching device as described in Appendix 27, wherein the seventh optical fiber is a line that enters from the second optical fiber and exits from the fourth optical fiber. (Note 29) The plurality of fifth optical fibers each include at least one line that enters from the first optical fiber and exits from the third optical fiber, and one line that enters from the third optical fiber and exits from the first optical fiber. The plurality of the aforementioned seven optical fibers each include at least one line that enters from the aforementioned second optical fiber and exits from the aforementioned fourth optical fiber, and one line that enters from the aforementioned fourth optical fiber and exits from the aforementioned second optical fiber. The line that enters the fifth optical fiber from the first optical fiber and exits the third optical fiber is connected to the line that enters the seventh optical fiber from the fourth optical fiber and exits the second optical fiber. The optical fiber branching and switching device according to Appendix 27, wherein a line entering the fifth optical fiber from the third optical fiber and exiting the first optical fiber is connected to a line entering the seventh optical fiber from the second optical fiber and exiting the fourth optical fiber. (Note 30) It comprises a first optical fiber, a second optical fiber, a third optical fiber, a plurality of fourth optical fibers, a plurality of fifth optical fibers, a sixth optical fiber, and a seventh optical fiber. The first optical fiber is connected to the second optical fiber and a plurality of the fourth optical fibers. The first optical fiber is connected to the third optical fiber and a plurality of the fifth optical fibers. The second optical fiber is connected to the sixth optical fiber, The aforementioned second optical fiber is connected to the aforementioned seventh optical fiber in an optical fiber branching and switching device. (Note 31) The first optical fiber is separated into a plurality of fourth optical fibers and a plurality of fifth optical fibers. The optical fiber branching and switching device according to Appendix 30, wherein the second optical fiber is separated into a plurality of the fourth optical fiber, the sixth optical fiber, and the seventh optical fiber. (Note 32) The first optical fiber is fanned in and fanned out to a plurality of fourth optical fibers and a plurality of fifth optical fibers. The optical fiber branching and switching device according to Appendix 30, wherein the second optical fiber is fanned in and fanned out to a plurality of the fourth optical fiber, the sixth optical fiber, and the seventh optical fiber. (Note 33) It comprises a first switching device, a second switching device, a third switching device, and a fourth switching device. One of the plurality of fifth optical fibers is connected to the sixth optical fiber via the first switching device and the second switching device. The optical fiber branching and switching device according to Appendix 32, wherein one of the plurality of fifth optical fibers is connected to the seventh optical fiber via the third and fourth switching devices. (Note 34) The fourth optical fiber comprises a line that enters from the second optical fiber and exits from the first optical fiber. The fifth optical fiber comprises a line that enters from the first optical fiber and exits from the third optical fiber. The sixth optical fiber comprises a line that exits the second optical fiber, The optical fiber branching and switching device according to Appendix 33, wherein the seventh optical fiber comprises a line that exits the second optical fiber. (Note 35) The fourth optical fiber comprises a line that enters from the first optical fiber and exits from the second optical fiber. The fifth optical fiber comprises a line that enters from the third optical fiber and exits to the first optical fiber. The sixth optical fiber comprises a line incident from the second optical fiber, The optical fiber branching and switching device according to Appendix 33, wherein the seventh optical fiber comprises a line incident from the second optical fiber. (Note 36) The sixth optical fiber is a line incident from the second optical fiber, The seventh optical fiber is a line that exits the second optical fiber, One of the plurality of fifth optical fibers is a line that enters from the third optical fiber and exits from the first optical fiber. The optical fiber branching and switching device according to Appendix 33, wherein one of the plurality of fifth optical fibers is a line that enters from the first optical fiber and exits from the third optical fiber. [Explanation of symbols]

[0122] 100 Optical fiber branching and switching device, 101 First optical fiber, 102 Second optical fiber, 103 Third optical fiber, 104 Fourth optical fiber, 105 Fifth optical fiber, 106 Sixth optical fiber, 200 Optical fiber branching and switching device, 201 First switching device, 202 Second switching device, 500 Optical fiber branching and switching device, 501 First optical fiber, 502 Second optical fiber, 503 Third optical fiber, 504 Fourth optical fiber, 505 Fifth optical fiber, 506 Sixth optical fiber, 507 Seventh optical fiber, 600 Optical fiber branching and switching device, 601 First switching device, 602 Second switching device, 900 Optical fiber branching and switching device, 901 First optical fiber, 902 Second optical fiber, 903 Third optical fiber, 904 Fourth optical fiber, 911 First switching device, 912 Second switching device, 1100 Optical fiber branching and switching device, 1101 First optical fiber, 1102 Second optical fiber, 1103 Third optical fiber, 1104 Fourth optical fiber, 1105 Fifth optical fiber, 1106 Sixth optical fiber, 1107 Seventh optical fiber, 1108 Eighth optical fiber, 1109 Ninth optical fiber, 1110 Tenth optical fiber, 1111 Eleventh optical fiber, 1112 Twelfth optical fiber, 1121 First switching device, 1122 Second switching device, 1123 Third switching device, 1124 Fourth switching device, 1400 Optical fiber branching and switching device, 1401 First optical fiber, 1402 Second optical fiber, 1403 Third optical fiber, 1404 Fourth optical fiber, 1405 Fifth optical fiber, 1406 Sixth optical fiber, 1407 Seventh optical fiber, 1408 Eighth optical fiber, 1409 9th optical fiber, 1410 10th optical fiber, 1411 11th optical fiber, 1500 Optical fiber branching and switching device, 1501 1st switching device, 1502 2nd switching device, 1503 3rd switching device, 1504 4th switching device, 1800 Optical fiber branching and switching device, 1801 1st optical fiber, 1802 2nd optical fiber, 1803 3rd optical fiber, 1804 4th optical fiber, 1805 5th optical fiber, 18066th optical fiber, 1807 7th optical fiber, 1808 8th optical fiber, 1811 1st switching device, 1812 2nd switching device, 2100 Optical fiber branch switching device, 2101 1st optical fiber, 2102 2nd optical fiber, 2103 3rd optical fiber, 2104 4th optical fiber, 2105 5th optical fiber, 2106 6th optical fiber, 2107 7th optical fiber, 2200 Optical fiber branch switching device, 2201 1st switching device, 2202 2nd switching device, 2203 3rd switching device, 2204 4th switching device

Claims

1. It comprises a first optical fiber, a second optical fiber, a third optical fiber, a fourth optical fiber, a fifth optical fiber, a sixth optical fiber, a seventh optical fiber, a plurality of eighth optical fibers, a plurality of ninth optical fibers, a plurality of tenth optical fibers, and a plurality of eleventh optical fibers. The first optical fiber is connected to the fifth optical fiber using a plurality of eight optical fibers. The second optical fiber is connected to the fifth optical fiber using a plurality of the ninth optical fibers. The third optical fiber is connected to the sixth optical fiber using a plurality of the tenth optical fibers. The fourth optical fiber is connected to the seventh optical fiber using a plurality of the eleventh optical fiber in an optical fiber branching and switching device.

2. The fifth optical fiber comprises a first plurality of cores, The optical fiber branching and switching device according to claim 1, wherein the first plurality of cores are separated into a plurality of eighth optical fibers and a plurality of ninth optical fibers.

3. The optical fiber branching and switching device according to claim 1, wherein the fifth optical fiber is fanned in and fanned out to a plurality of eighth optical fibers and a plurality of ninth optical fibers.

4. comprising a first switching device, a second switching device, a third switching device, and a fourth switching device, Multiple eight optical fibers are connected to multiple ten optical fibers via the first and second switching devices. The optical fiber branching and switching device according to claim 1, wherein a plurality of the 9th optical fibers are connected to a plurality of the 11th optical fibers via the third switching device and the fourth switching device.

5. The eighth optical fiber comprises a line that enters from the fifth optical fiber and exits from the first optical fiber, The ninth optical fiber comprises a line that enters from the second optical fiber and exits from the fifth optical fiber. The tenth optical fiber comprises a line that enters from the third optical fiber and exits to the sixth optical fiber. The optical fiber branching and switching device according to claim 4, wherein the eleventh optical fiber includes a line that enters from the eighth optical fiber and exits to the fourth optical fiber.

6. The plurality of eight optical fibers each include at least one line that enters from the first optical fiber and exits to the fifth optical fiber and one line that enters from the fifth optical fiber and exits to the first optical fiber, The plurality of ninth optical fibers each include at least one line that enters from the second optical fiber and exits to the fifth optical fiber, and one line that enters from the fifth optical fiber and exits to the second optical fiber. The plurality of the tenth optical fibers each include at least one line that enters from the third optical fiber and exits to the sixth optical fiber, and one line that enters from the sixth optical fiber and exits to the third optical fiber. The plurality of 11 optical fibers each include at least one line that enters from the 4 optical fiber and exits to the 7 optical fiber, and one line that enters from the 7 optical fiber and exits to the 4 optical fiber. The line that enters the eighth optical fiber from the first optical fiber and exits the fifth optical fiber is connected to the line that enters the tenth optical fiber from the sixth optical fiber and exits the third optical fiber. The line that enters the eighth optical fiber from the fifth optical fiber and exits the first optical fiber is connected to the line that enters the tenth optical fiber from the third optical fiber and exits the sixth optical fiber. A line entering the 9th optical fiber from the 2nd optical fiber and exiting the 5th optical fiber is connected to a line entering the 11th optical fiber from the 7th optical fiber and exiting the 4th optical fiber. The optical fiber branching and switching device according to any one of claims 1 to 5, wherein a line entering the 9th optical fiber from the 5th optical fiber and exiting the 2nd optical fiber is connected to a line entering the 11th optical fiber from the 4th optical fiber and exiting the 7th optical fiber.

7. It comprises a first optical fiber, a second optical fiber, a third optical fiber, a plurality of fourth optical fibers, a plurality of fifth optical fibers, a sixth optical fiber, and a seventh optical fiber. The first optical fiber is connected to the second optical fiber using a plurality of the fourth optical fibers. The first optical fiber is connected to the third optical fiber using a plurality of the fifth optical fibers. The second optical fiber is connected to the sixth optical fiber, The second optical fiber is connected to the seventh optical fiber in an optical fiber branching and switching device.

8. The first optical fiber is separated into a plurality of fourth optical fibers and a plurality of fifth optical fibers, The optical fiber branching and switching device according to claim 7, wherein the second optical fiber is separated into a plurality of fourth optical fibers, sixth optical fibers, and seventh optical fibers.

9. The first optical fiber is fanned in and fanned out to a plurality of fourth optical fibers and a plurality of fifth optical fibers, The optical fiber branching and switching device according to claim 7, wherein the second optical fiber is fanned in and fanned out to a plurality of fourth optical fibers, sixth optical fibers, and seventh optical fibers.

10. comprising a first switching device, a second switching device, a third switching device, and a fourth switching device, One of the plurality of fifth optical fibers is connected to the sixth optical fiber via the first switching device and the second switching device. The optical fiber branching and switching device according to claim 9, wherein one of the plurality of fifth optical fibers is connected to the seventh optical fiber via the third switching device and the fourth switching device.

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