Optical fiber connector

Abstract

The present invention comprises: a converter (3) that converts the core interval of SMFs (2) to the interval of cores of an MCF (1), and has a plurality of conversion units (31), each of which on one end side is set to one of a polarity A and a polarity B, and each of which on the other end side is set to the other of the polarity A and the polarity B; a plurality of SMFs (5, 7) that are connected to said one end side of the converter (3); and an MCF (41, 42) that is connected to the other end side of the converter (3) and has a plurality of cores. The ends of the SMFs (5, 7) connected to the converter (3) are set to one of the polarity A and the polarity B, and the ends of the cores included in the MCF (41, 42) connected to the converter (3) are set to the other of the polarity A and the polarity B.

Description

Optical Fiber Connector 【0001】 The present disclosure relates to an optical fiber connector for connecting a single-core optical fiber and a multi-core optical fiber. 【0002】 For the purpose of expanding the transmission capacity, multi-core optical fibers (hereinafter abbreviated as "MCF") having a plurality (for example, four) of cores (waveguides) have been put into practical use. Non-Patent Document 1 discloses a technique for a standard cladding diameter MCF adopting a step-index (SI) type refractive index distribution. When connecting a single-core optical fiber (hereinafter abbreviated as "SMF") to such an MCF, a FIFO (Fan-in / Fan-out; optical fiber connector) is used. 【0003】 T. Matsuiet al., "Design and applicability of multi-core fiberswith standard claddingdiameter", J. Lightwave Technol., vol. 38, pp. 6065,2020. 【0004】 Since the MCF has a plurality of core regions, the core arrangements are different at both ends. That is, the core arrangement of the long-shaped MCF viewed from one end side and the core arrangement viewed from the other end side are not the same but are mirror-image arrangements. For example, when the core arrangement of an MCF having four cores viewed from one end side is numbered 1, 2, 3, 4 clockwise (this core arrangement is referred to as "polarity A"), the core arrangement viewed from the other end side is numbered 1, 2, 3, 4 counterclockwise (this core arrangement is referred to as "polarity B"). 【0005】 Therefore, when the ends of a plurality of SMFs to be connected are of polarity A, the ends of the MCF to be connected to this end need to be of polarity B in which the cores are mirror-image arranged with respect to polarity A. In this case, the end of the FIFO used to connect both needs to be of polarity B on the SMF side and of polarity A on the MCF side. 【0006】On the other hand, if the end of the SMF to be connected is polarity B, then the end of the MCF to be connected to this end must be polarity A. In this case, the FIFO used to connect the two must have polarity A on the SMF side and polarity B on the MCF side. In other words, two types of FIFOs (optical fiber connectors) must be prepared depending on the polarity of the ends of the SMF and MCF to be connected. 【0007】 Furthermore, the FIFO has a converter that converts the spacing between each core in multiple SMFs to the spacing between each core in the core area of ​​an MCF. Two types of converters are also needed, depending on the polarity of the SMF and MCF. Since the manufacturing process for the converters is complex, manufacturing two types of converters complicates the manufacturing process and leads to higher costs. 【0008】 This disclosure has been made in view of the above circumstances, and its purpose is to provide an optical fiber connector that can be manufactured using the same converter and that can connect MCF and SMF to be connected in accordance with the core arrangement of the MCF and SMF. 【0009】An optical fiber connector according to one aspect of the present disclosure is an optical fiber connector for connecting a plurality of single-core optical fibers, each having one of a first core arrangement and a second core arrangement which is a mirror image of the first core arrangement, and a plurality of multi-core optical fibers having the other of the first core arrangement and the second core arrangement, wherein each of the two conversion units at one end is one of the first core arrangement and the second core arrangement, and each of the two conversion units at the other end is the other of the first core arrangement and the second core arrangement, and each The device comprises a converter that converts the core spacing of a single-core optical fiber to the spacing of each core in a multi-core optical fiber; a plurality of connecting single-core optical fibers connected to one end of the converter; and a connecting multi-core optical fiber having a plurality of cores connected to the other end of the converter, wherein the end of the connecting single-core optical fiber connected to the converter is one of the first core arrangement and the second core arrangement, and the end of each core included in the connecting multi-core optical fiber connected to the converter is the other of the first core arrangement and the second core arrangement. 【0010】 According to this disclosure, it is possible to manufacture using the same converter, and to connect the MCF and SMF to be connected in accordance with the core arrangement of the MCF and SMF. 【0011】Figure 1A is a schematic explanatory diagram showing a FIFO according to the first embodiment, and the SMF and MCF connected thereto. Figure 1B(a) is a view from the direction of X1 shown in Figure 1A, and Figure 1B(b) is a view from the opposite direction of X1. Figure 2A is a schematic explanatory diagram showing a FIFO according to the second embodiment, and the SMF and MCF connected thereto. Figure 2B is a view from the direction of X2 shown in Figure 2A. Figure 3A is a schematic explanatory diagram showing a FIFO according to the third embodiment, and the SMF and MCF connected thereto. Figure 3B is a view from the direction of X3 shown in Figure 3A. Figure 4A is a schematic explanatory diagram showing a FIFO according to the fourth embodiment, and the SMF and MCF connected thereto. Figure 4B is a view from the direction of X4 shown in Figure 4A. Figure 5 is a perspective view showing an SMF with a tape structure. 【0012】 Embodiments of this disclosure will be described in detail below with reference to the drawings. However, this disclosure is not limited to the embodiments shown below. These examples are illustrative, and this disclosure can be implemented in various modified and improved forms based on the knowledge of those skilled in the art. In this specification and in the drawings, components with the same reference numerals refer to the same components. 【0013】 [Description of the First Embodiment] Hereinafter, an embodiment will be described with reference to the drawings. Figure 1A is a schematic explanatory diagram showing the state in which the FIFO 4a (optical fiber connector) according to the first embodiment is connected to a multicore optical fiber 1 (hereinafter abbreviated as "MCF1") and a single-core optical fiber 2 (hereinafter abbreviated as "SMF2"). Figure 1B(a) is a view of SMF2 in Figure 1A from the direction of arrow X1, and Figure 1B(b) is a view of SMF2 from the opposite side of arrow X1. In the following, the left and right directions in Figure 1A will be referred to as left and right, respectively. 【0014】In this embodiment, we will describe an example in which the number of cores in MCF1 is "4", and the SMF2 connected to MCF1 via FIFO 4a is also set to four. That is, MCF1 has four cores 1-1, 1-2, 1-3, and 1-4. Note that the number of cores in MCF1 and the number of SMF2 are not limited to four; it is sufficient if the number of SMF2 matches the number of cores in MCF1. 【0015】 In the FIFO 4a according to the first embodiment, each of the cores 1-1 to 1-4 of the MCF1 is connected to four SMF2s (2-1, 2-2, 2-3, 2-4). Hereinafter, when referring to one of the four SMF2s (2-1, 2-2, 2-3, 2-4) specifically, a suffix will be added, such as "SMF2-1," and when not specifically referring to one or referring to them collectively, they will be referred to as "SMF2" without a suffix. The same applies to other reference numerals. 【0016】 Each suffix "-1" to "-4" indicates the number of each core included in each SMF and MCF1. Therefore, the FIFO4a shown in Figure 1A connects multiple SMF2s and each core included in MCF1 with the same number. Specifically, it connects SMF2-1 to core 1-1, SMF2-2 to core 1-2, SMF2-3 to core 1-3, and SMF2-4 to core 1-4. 【0017】 The four SMF2s are assumed to be arranged symmetrically with respect to an arbitrary center line. That is, as shown in Figure 1B(a), of the four SMF2s, SMF2-1, 2-2 and SMF2-3, 2-4 are arranged symmetrically with respect to the center line C1. Similarly, of the four cores 1-1, 1-2, 1-3, and 1-4 included in MCF1, the two cores 1-1, 1-2 and the two cores 1-3, 1-4 are arranged symmetrically with respect to a line. 【0018】Furthermore, as shown in Figure 1B(b), the arrangement of each SMF2-1 to 2-4 when SMF2 is viewed from the opposite direction of arrow X1 (first core arrangement) is defined as "Polarity A," and as shown in Figure 1B(a), the arrangement of each SMF2-1 to 2-4 when SMF2 is viewed from the direction of arrow X1 (second core arrangement) is defined as "Polarity B." Similarly, the arrangement where the top left is ○-1, the bottom left is ○-2, the top right is ○-3, and the bottom right is ○-4 is defined as "Polarity A," and the arrangement where the top left is ○-3, the bottom left is ○-4, the top right is ○-1, and the bottom right is ○-2 is defined as "Polarity B." Since Polarity A and Polarity B are mirror images of each other, when the core arrangement of Polarity A and the core arrangement of Polarity B are placed facing each other, the numbers of each core will match. 【0019】 Figure 1A shows the FIFO 4a used to connect the SMF2 (right end) to be connected, where the right end is polarity A, and the MCF1 (left end) is polarity B. 【0020】 As shown in Figure 1A, the FIFO 4a comprises a converter 3, a connecting MCF 41, and four connecting SMF 5 (5-1 to 5-4). The MCF 41 comprises four cores 6-1 to 6-4. 【0021】 The converter 3 is a component for connecting each of the cores 1-1 to 1-4 included in the MCF1 with each of the SMF2 (2-1 to 2-4). The converter 3 is equipped with conversion sections 31 (31-1, 31-2, 31-3, 31-4) such that the spacing between each of the cores 1-1 to 1-4 included in the MCF1 is the same as the spacing between the cores of each SMF2 (spacing approximately the outer diameter of the SMF2). The number of conversion sections 31 should be equal to or greater than the number of cores included in the MCF. 【0022】 The converter 3 has four connecting single-core optical fibers 5 (hereinafter abbreviated as "SMF5") connected to one end and a connecting multi-core optical fiber 41 (hereinafter abbreviated as "MCF41") connected to the other end. It is desirable that the cores 6-1 to 6-4 of the converter 3 and the MCF41 have the same MFD (mode field diameter). It is also desirable that the cores of the converter 3 and each of the SMF5 have the same MFD. 【0023】The connection between the converter 3 and the SMF 5 requires centering, and the connection between the converter 3 and the MCF 41 requires rotational centering. Methods for connecting the converter 3 to the MCF 41 and the converter 3 to the SMF 5 include using ultraviolet-curing resin, fusion bonding, and applying silicone oil and heating with a high-power laser. 【0024】 Furthermore, a self-forming waveguide may be created and connected by applying an ultraviolet-curing resin and propagating ultraviolet light from MCF41, SMF5, or the converter 3. 【0025】 The converter 3 may be made using a PLC (Planar Lightwave Circuit), or it may be made by bundling and melt-stretching SMF5. Alternatively, the converter 3 may have a conversion section 31 that forms an optical waveguide made of glass using a femtosecond laser or the like. The converter 3 may also have an optical waveguide made of ultraviolet-curing resin. The MCF41 and SMF5 may be made of quartz or resin. When connecting the converter 3 to the MCF41, and when connecting the converter 3 to the SMF5, the MCF41 and SMF5 may be fixed in advance to a base with a V-groove before connecting them. 【0026】 The left end of converter 3 is polarity B, and the right end of SMF 5 is polarity A. Therefore, the conversion sections 31-1 to 31-4 of converter 3 and each SMF 5-1 to 5-4 can be connected using the same number. Also, the left end of each SMF 5, that is, the end that connects each SMF 5 to each SMF 2, is polarity B. 【0027】 The right end of the converter 3 is polarity A, and the left end of the MCF 41 is polarity B. Therefore, the conversion sections 31-1 to 31-4 of the converter 3 and the cores 6-1 to 6-4 included in the MCF 41 can be connected to each other with the same number. Also, the right end of the MCF 41, that is, the end that connects the MCF 41 to the MCF 1, is polarity A. 【0028】 The converter 3 has a conversion unit 31 that converts the core spacing of each SMF 5 to the spacing of each core 6-1 to 6-4 of the MCF 41. 【0029】Furthermore, the end (right end) of the SMF 5 (connecting single-core optical fiber 5) that is connected to the converter 3 is one of the first core configuration (polarity A) and the second core configuration (polarity B), and the end (left end) of each core 6-1 to 6-4 contained in the MCF 41 (connecting multi-core optical fiber 41) that is connected to the converter 3 is the other of the first core configuration (polarity A) and the second core configuration (polarity B). 【0030】 Specifically, FIFO 4a is configured such that four SMF 5s are connected to the left end of the converter 3, and an MCF 41 equipped with four cores 6-1 to 6-4 is connected to the right end of the converter 3. The left end of the SMF 5 is polarity B, and the right end of the SMF 2 to be connected is polarity A, so identical numbers on both sides can be connected. Similarly, the right end of the MCF 41 is polarity A, and the left end of the MCF 1 to be connected is polarity B, so identical numbers on both sides can be connected. 【0031】 If one end of the converter 3 has the second core configuration (polarity B) and the other end has the first core configuration (polarity A), and each end of the SMF2 to be connected has the first core configuration (polarity A) and the end of the MCF1 has the second core configuration (polarity B), then the polarity A end of the SMF5 is connected to the converter 3, and the polarity B end of the MCF41 is connected to the converter 3. 【0032】 Therefore, if the end of the SMF2 to be connected has polarity A, the SMF5-1 to 5-4 included in FIFO4a can be connected in correspondence with SMF2-1 to 2-4. Also, if the ends of each core 1-1 to 1-4 of the MCF1 to be connected have polarity B, the cores 6-1 to 6-4 of the MCF41 included in FIFO4a can be connected in correspondence with the cores 1-1 to 1-4 of the MCF1. In other words, by using the optical fiber connector (FIFO4a) according to the first embodiment, SMF2 and MCF1 can be connected. 【0033】In the FIFO 4a according to the first embodiment shown in Figure 1A, the connection SMF 5 and SMF 2 are separated, and the connection MCF 41 and MCF 1 are separated. However, the connection SMF 5 and SMF 2 may be integrated, and the connection MCF 41 and MCF 1 may also be integrated. 【0034】 [Description of the Second Embodiment] Next, the second embodiment will be described. The FIFO 4b according to the second embodiment is used when the end of the SMF 2 to be connected is polarity B (second core arrangement) and the end of the MCF 1 is polarity A (first core arrangement). Figure 2A is a schematic explanatory diagram showing the state in which the FIFO 4b (optical fiber connector) according to the second embodiment is connected to the MCF 1 and the SMF 2. Figure 2B is a view from the direction of arrow X2 in Figure 2A. 【0035】 The FIFO 4b shown in Figure 2A comprises a converter 3, an MCF 42, and four SMF 7s (7-1 to 7-4). The MCF 42 has four cores 8-1 to 8-4. The left side of the converter 3 is connected to the MCF 42, and the right side is connected to the four SMF 7s. 【0036】 The converter 3 is a component for connecting each core 1-1 to 1-4 contained in the MCF1 with each SMF2. The converter 3 has the same configuration as the converter 3 provided in the FIFO 4a shown in Figure 1A. The converter 3 shown in Figure 2A is arranged in the opposite direction to the converter 3 shown in Figure 1A. That is, the right end of the converter 3 (the end on the SMF2 side) is polarity B, and the left end (the end on the MCF1 side) is polarity A. 【0037】As shown in Figure 2B, the left ends (converter 3 side) of the four SMF7s are designated as follows: SMF7-3 at the top left, SMF7-4 at the bottom left, SMF7-1 at the top right, and SMF7-2 at the bottom right. In other words, they have polarity B. The right end of converter 3 also has polarity B, similar to converter 3 shown in Figure 1A. Therefore, in FIFO 4b shown in Figure 2A, conversion unit 31-1 is connected to SMF7-3, conversion unit 31-2 is connected to SMF7-4, conversion unit 31-3 is connected to SMF7-1, and conversion unit 31-4 is connected to SMF7-2 on the right side of converter 3. In other words, different numbers are connected to each other. Furthermore, the right end of FIFO 4b (the right end of SMF7) has polarity A, and can be connected to the ends of SMF2, which have polarity B, with the same numbers. 【0038】 On the other hand, the right end of MCF42 (the side facing converter 3) has core 8-1 at the top left, core 8-2 at the bottom left, core 8-3 at the top right, and core 8-4 at the bottom right. That is, it is polarity A. Also, the left end of converter 3 is polarity A, similar to converter 3 shown in Figure 1A. Therefore, in FIFO4b shown in Figure 2A, the conversion unit 31-1 is connected to core 8-3, the conversion unit 31-2 is connected to core 8-4, the conversion unit 31-3 is connected to core 8-1, and the conversion unit 31-4 is connected to core 8-2. In other words, different numbers are connected to each other. Furthermore, the left end of FIFO4b (the left end of MCF42) is polarity B, and can be connected to the ends of MCF1, which are polarity A, with the same numbers connected to each other. 【0039】 As described above, in FIFO4b, polarities B are connected between converter 3 and each SMF7, and polarities A are connected between converter 3 and MCF42. In other words, different numbers are connected in two places. Because there is an even number of places (two in this case) where the same polarity is connected, the core number (the number indicated by the suffix) changes an even number of times. 【0040】Therefore, the same core numbers will be connected between the four SMF2s and the MCF1s that are to be connected. Specifically, by using FIFO4b, SMF2-1 shown in Figure 2A will be connected to core 1-1 of MCF1, SMF2-2 will be connected to core 1-2 of MCF1, SMF2-3 will be connected to core 1-3 of MCF1, and SMF2-4 will be connected to core 1-4 of MCF1. 【0041】 Therefore, it becomes possible to manufacture a FIFO 4a (see Figure 1A) for connecting an SMF2 with polarity A at one end and an MCF1 with polarity B at the other end, and a FIFO 4b (see Figure 2A) for connecting an SMF2 with polarity B at one end and an MCF1 with polarity A at the other end, using the same converter 3. 【0042】 In other words, if one end of the converter 3 has the second core configuration (polarity B) and the other end has the first core configuration (polarity A), and each end of the SMF2 to be connected has the second core configuration (polarity B) and the end of the MCF1 has the first core configuration (polarity A), then the polarity B end of the SMF7 is connected to one end of the converter 3, and the polarity A end of the MCF42 is connected to the other end of the converter 3. 【0043】Thus, the FIFO 4a, 4b (fiber optic connector) according to this embodiment is an optical fiber connector (FIFO 4a, 4b) that connects a plurality of single-core optical fibers (SMF2) whose ends are arranged in one of the first core arrangement and the second core arrangement that is a mirror image arrangement with respect to the first core arrangement, and a multi-core optical fiber (MCF1) having a plurality of cores whose ends are arranged in the other core arrangement of the first core arrangement and the second core arrangement. The FIFO 4a, 4b has a conversion unit 31. The conversion unit 31 on one end side is arranged in one of the first core arrangement and the second core arrangement, and the conversion unit 31 on the other end side is arranged in the other of the first core arrangement and the second core arrangement. A converter 3 that converts the core pitch of each single-core optical fiber (SMF2) into the pitch of each core of the multi-core optical fiber (MCF1), a plurality of single-core optical fibers for connection (SMF5, 7) connected to one end side of the converter 3, and a multi-core optical fiber for connection (MCF41, 42) having a plurality of cores connected to the other end side of the converter 3 are provided. The ends of the SMF5, 7 connected to the converter 3 are arranged in one of the first core arrangement and the second core arrangement, and the ends of each core included in the MCF41, 42 connected to the converter 3 are arranged in the other of the first core arrangement and the second core arrangement. 【0044】 In this embodiment, when the end of the MCF1 to be connected has the polarity B (the second core arrangement), the FIFO 4a shown in FIG. 1A is used. When the polarity is A (the first core arrangement), the MCF1 and four SMF2 can be connected by using the FIFO 4b shown in FIG. 2A. 【0045】 At this time, the two FIFOs 4a and 4b use a common converter 3. Therefore, the manufacturing processes of the two FIFOs 4a and 4b can be simplified, and the manufacturing cost can be reduced. That is, the FIFOs 4a and 4b according to the first and second embodiments can be manufactured using the same converter 3, and connection can be made according to the core arrangements of the ends of the MCF1 and SMF2 to be connected. 【0046】[Description of the Third Embodiment] Next, the third embodiment will be described. The FIFO 4c according to the third embodiment is used when the end of the SMF 2 to be connected has a polarity A (first core arrangement) and the end of the MCF 1 has a polarity B (second core arrangement), similar to the first embodiment described above. FIG. 3A is an explanatory diagram schematically showing a state where the FIFO 4c (optical fiber connector) according to the third embodiment is connected to the MCF 1 and the SMF 2. FIG. 3B is a view seen from the direction of arrow X3 in FIG. 3A. 【0047】 The FIFO 4c shown in FIG. 3A includes a converter 3, an MCF 41 (multi-core optical fiber for connection), and four SMFs 5 (single-core optical fibers for connection). The MCF 41 includes four cores 6-1 to 6-4. The right end of the converter 3 is connected to the MCF 41, and the left end is connected to the four SMFs 5. 【0048】 The converter 3 is a member for connecting each of the cores 1-1 to 1-4 included in the MCF 1 and each SMF 2. The converter 3 has the same configuration as the converter 3 included in the FIFO 4a shown in FIG. 1A. The left end (the end on the SMF 2 side) of the converter 3 has a polarity B, and the right end (the end on the MCF 1 side) has a polarity A. The converter 3 is inverted up and down compared to the converter 3 shown in FIG. 1A. That is, the conversion part 31 of the converter 3 shown in FIG. 1A is arranged to be rotated 180 degrees around the axis in the left-right direction. 【0049】 As shown in FIG. 3A, the left end of the converter 3 has a polarity B (second core arrangement), and the ends of each SMF 5 have a polarity A (first core arrangement). However, since each conversion part 31 of the converter 3 is inverted up and down, when the left end of the converter 3 is opposed to the right end of the SMF 5, the core numbers do not match. Specifically, the conversion part 31-1 of the converter 3 is connected to the SMF 5-4, the conversion part 31-2 is connected to the SMF 5-3, the conversion part 31-3 is connected to the SMF 5-2, and the conversion part 31-4 is connected to the SMF 5-1. That is, different numbers are connected. Also, the left end of the FIFO 4c (the left end of the SMF 5) has a polarity B, and the same numbers can be connected to the SMF 2 having a polarity A. 【0050】 On the other hand, the right end of the converter 3 is polarity A (first core configuration), and the left end of the MCF 41 is polarity B (second core configuration). However, since the conversion unit 31 of the converter 3 is inverted vertically, when the right end of the converter 3 is placed opposite the left end of the MCF 41, the core numbers do not match. Specifically, conversion unit 31-1 is connected to core 6-4, conversion unit 31-2 is connected to core 6-3, conversion unit 31-3 is connected to core 6-2, and conversion unit 31-4 is connected to core 6-1. In other words, different numbers are connected. Also, the right end of FIFO 4c (the right end of MCF 41) is polarity A, and it is possible to connect identical numbers to MCF 1, which is polarity B. 【0051】 As described above, in the FIFO4c according to the third embodiment, different core numbers are connected between the converter 3 and the SMF5, and different core numbers are connected between the converter 3 and the MCF41. However, since these connections are made at even-numbered locations, the core number changes twice (an even number of times). Therefore, the same core numbers are connected between the four SMF2s that are to be connected and the MCF1. Specifically, as shown in Figure 3A, SMF2-1 is connected to core 1-1 of MCF1, SMF2-2 is connected to core 1-2 of MCF1, SMF2-3 is connected to core 1-3 of MCF1, and SMF2-4 is connected to core 1-4 of MCF1. 【0052】 In other words, it becomes possible to connect the MCF1 and SMF2 to be connected by a FIFO 4c manufactured using a converter 3 having the same configuration as the aforementioned FIFOs 4a and 4b. 【0053】[Description of the Fourth Embodiment] Next, the fourth embodiment will be described. The FIFO 4d according to the fourth embodiment is used when the end of the SMF2 to be connected is polarity B (second core arrangement) and the end of the MCF1 is polarity A (first core arrangement), similar to the second embodiment described above. Figure 4A is a schematic explanatory diagram showing the state in which the FIFO 4d (optical fiber connector) according to the fourth embodiment is connected to the MCF1 and the SMF2. Figure 4B is a view from the direction of arrow X4 in Figure 4A. 【0054】 The FIFO4c shown in Figure 4A comprises a converter 3, an MCF42 (multicore optical fiber for connection), and four SMF7 (single-core optical fibers for connection). The MCF42 has four cores 8-1 to 8-4. The left end of the converter 3 is connected to the MCF42, and the right end is connected to the four SMF7. 【0055】 The converter 3 is a component for connecting each core 1-1 to 1-4 contained in the MCF1 with each SMF2. The converter 3 has the same configuration as the converter 3 provided in the FIFO 4b shown in Figure 2A. The right end of the converter 3 (the end on the SMF2 side) is polarity B, and the left end (the end on the MCF1 side) is polarity A. The converter 3 is inverted vertically compared to the converter 3 shown in Figure 2A. That is, the conversion section 31 of the converter 3 shown in Figure 2A is arranged in a configuration rotated 180 degrees around the left-right axis. 【0056】 As shown in Figure 4A, the right end of the converter 3 is polarity B (second core configuration), and the left end of each SMF7 is also polarity B. When the right end of the converter 3 is placed opposite the left end of the SMF7, the core numbers do not match. Specifically, the converter unit 31-1 of the converter 3 is connected to SMF7-2, the converter unit 31-2 is connected to SMF7-1, the converter unit 31-3 is connected to SMF7-4, and the converter unit 31-4 is connected to SMF7-3. In other words, different numbers are connected to each other. Also, the right end of FIFO4d (the right end of SMF7) is polarity A, and it is possible to connect identical numbers to SMF2, which is polarity B. 【0057】On the other hand, the left end of the converter 3 (the end on the MCF1 side) is polarity A (first core arrangement), and the right end of the MCF42 is also polarity A. When the left end of the converter 3 is placed opposite the right end of the MCF42, the core numbers do not match. Specifically, the conversion unit 31-1 of the converter 3 is connected to core 8-2 of the MCF42, the conversion unit 31-2 is connected to core 8-1 of the MCF42, the conversion unit 31-3 is connected to core 8-4 of the MCF42, and the conversion unit 31-4 is connected to core 8-3 of the MCF42. In other words, different numbers are connected. Also, the left end of the FIFO4d (the left end of the MCF42) is polarity B, and it is possible to connect identical numbers to the MCF1, which is polarity A. 【0058】 As described above, in FIFO4d, different core numbers are connected between converter 3 and SMF7, and different core numbers are connected between converter 3 and MCF42. However, since these connections are made at even-numbered locations, the core number changes twice (an even number of times). Therefore, the same core numbers are connected between the four SMF2s and MCF1s that are to be connected. Specifically, as shown in Figure 4A, SMF2-1 is connected to core 1-1 of MCF1, SMF2-2 is connected to core 1-2 of MCF1, SMF2-3 is connected to core 1-3 of MCF1, and SMF2-4 is connected to core 1-4 of MCF1. 【0059】 In other words, it becomes possible to connect the MCF1 and SMF2 to be connected by using a FIFO 4d manufactured with a converter 3 having the same configuration as the aforementioned FIFOs 4a, 4b, and 4c. 【0060】 Thus, the same effects as those of the FIFOs 4a and 4b described above can be obtained with the FIFOs 4c and 4d shown in the third and fourth embodiments. That is, when the end of the MCF1 to be connected has polarity B (second core arrangement), the FIFO 4c shown in Figure 3A is used, and when it has polarity A (first core arrangement), the FIFO 4d shown in Figure 4A is used to connect the MCF1 and the four SMFs 2. 【0061】In this case, the two FIFOs 4c and 4d use a common converter 3. Therefore, the manufacturing process for the two FIFOs 4c and 4d can be simplified, and manufacturing costs can be reduced. That is, the FIFOs 4c and 4d according to the third and fourth embodiments can be manufactured using the same converter 3, and connections can be made according to the core arrangement at the ends of the MCF1 and SMF2 to be connected. 【0062】 Figure 5 is an explanatory diagram showing a modified example of an SMF21 (single-core optical fiber) connected to MCF1 using FIFOs 4a to 4d. As shown in Figure 5, in this modified example, the four SMF21s are arranged in a tape structure. Specifically, the four SMF21-1 to 21-4 are arranged in parallel with each other. 【0063】 Even with SMF21 having such a tape structure, if these are bundled together and arranged in a square shape as shown in Figure 2B(a), it becomes possible to connect them to MCF1 using the aforementioned FIFO4a to 4d. 【0064】 When using tape-structured SMF21, the polarity can be adjusted by arranging each SMF21-1 to 21-4 clockwise or counterclockwise. Alternatively, each core included in the tape-structured SMF21 may be separated into single cores and connected to the converter 3. 【0065】 This disclosure is not limited to the embodiments described above, and numerous modifications are possible within the scope of its essence. 【0066】 1. Multicore optical fiber (MCF) 1-1 to 1-4 Cores 2. (2-1 to 2-4) Single-core optical fiber (SMF) 3. Converters 4a, 4b, 4c, 4d FIFO (Optical Fiber Connector) 5. (5-1 to 5-4) Single-core optical fiber (SMF) for connection 6-1 to 6-4 Cores 7. (7-1 to 7-4) Single-core optical fiber (SMF) for connection 8-1 to 8-4 Cores 31. (31-1 to 31-4) Converters 41, 42 Multicore optical fiber (MCF) for connection

Claims

1. An optical fiber connector for connecting a plurality of single-core optical fibers, each having one of a first core arrangement and a second core arrangement which is a mirror image of the first core arrangement, and a multi-core optical fiber having a plurality of cores, each having the other of the first and second core arrangements, wherein the connector has a plurality of conversion units, each conversion unit at one end having one of the first and second core arrangements, and each conversion unit at the other end having the other of the first and second core arrangements, and converts the core spacing of each single-core optical fiber to the spacing of each core of the multi-core optical fiber; a plurality of connecting single-core optical fibers connected to the one end of the converter; and a connecting multi-core optical fiber having a plurality of cores, each having a plurality of cores, wherein the end of the connecting single-core optical fiber connected to the converter has one of the first and second core arrangements. An optical fiber connector in which the end of each core included in the connecting multicore optical fiber that is connected to the converter is arranged in the other of the first core arrangement and the second core arrangement.

2. The optical fiber connector according to claim 1, wherein each conversion unit at one end of the converter has the second core arrangement, each conversion unit at the other end has the first core arrangement, the end of the connecting single-core optical fiber with the first core arrangement is connected to the one end, and the end of the connecting multi-core optical fiber with the second core arrangement is connected to the other end.

3. The optical fiber connector according to claim 1, wherein each conversion unit at one end of the converter has the second core arrangement, each conversion unit at the other end has the first core arrangement, the end of the connecting single-core optical fiber with the second core arrangement is connected to the one end, and the end of the connecting multi-core optical fiber with the first core arrangement is connected to the other end.

4. The optical fiber connector according to claim 1, wherein the number of single-core optical fibers for connection, the number of conversion units, and the number of cores included in the multi-core optical fiber for connection are the same.

5. The optical fiber connector according to claim 4, wherein the number of single-core optical fibers for connection, the number of conversion units, and the number of cores included in the multi-core optical fiber for connection are four.

6. The optical fiber connector according to claim 1, wherein the converter includes a PLC (Planer Lightwave Circuit).

7. The optical fiber connector according to claim 1, wherein each of the single-core optical fibers is in a tape structure.

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