Optical fiber communication system, plastic optical fiber cable and active optical cable

Abstract

An optical fiber communication system is provided with a plastic optical fiber cable (10), light-emitting elements (3, 3 ') formed from a micro-LED array having a number a (a > = 2) of micro-LEDs, and light-receiving elements (4, 4') formed from a photodiode array having a number a or more photodiodes, the plastic optical fiber cable (10) further has a cover layer on the outside of a plastic optical fiber formed from two or more cores and a first sheath layer surrounding the peripheries of the cores, b or more cores (a < = b) among the two or more cores are effective cores for receiving light from the light-emitting element, the cores are formed from an acrylic resin, and b or more cores are effective cores for receiving light from the light-emitting element. The plastic optical fiber cable 10 has a static bending loss of 0.2 dB or less when the bending radius r is 3 mm.

Description

Technical Field

[0001] This invention relates to optical fiber communication systems, plastic optical fiber cables, and active optical cables. Background Technology

[0002] Previously, fiber optic communication systems that used micro-LED arrays with micro-LEDs as light-emitting elements and photodiode arrays as light-receiving elements were used for optical data communication. In such fiber optic communication systems, by incorporating multiple micro-LEDs in the light-emitting element, it is possible to communicate large amounts of optical data (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: US Patent No. 11,476,942 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, in conventional optical fiber communication systems, the optical fibers that make up the optical data communication cables are single-core or have fewer cores than the number of micro LEDs used as light-emitting elements. Therefore, it is necessary to convert a large amount of data into light and transmit it according to the amount of data to be communicated, which results in higher power consumption and higher costs.

[0008] In addition, in the aforementioned fiber optic communication systems, the optical fiber is mostly bent and installed in the equipment. However, when using fiber optic cables with glass optical fibers, there is a possibility of transmission obstacles caused by breakage.

[0009] Given these issues, multi-core plastic optical fibers with more cores than those used in traditional optical data communication are known and are suitable for image transmission applications. However, they have the following problems: Generally, as the bending radius of the plastic optical fiber increases, the light loss increases and the communication distance decreases. There is still room for improvement in terms of bending loss when the fiber is bent.

[0010] Therefore, the object of the present invention is to provide an optical fiber communication system that uses a micro-LED array with micro-LEDs as the light-emitting element and a photodiode array as the light-receiving element, and the optical fiber communication system has excellent mechanical strength resistance to bending, few communication errors, and excellent cost reduction of plastic optical fiber cables.

[0011] Solution for solving the problem

[0012] In order to solve the above-mentioned problems, the inventors conducted in-depth research and found that by determining the relationship between the number of micro LEDs constituting the light-emitting element of the optical fiber communication system and the number of cores of the plastic optical fiber constituting the light-receiving element, and by determining the static bending loss when the bending radius r=3mm, the problems of the prior art can be solved, and thus the present invention is completed.

[0013] That is, the present invention is as follows. [1]

[0015] An optical fiber communication system having:

[0016] Plastic fiber optic cables

[0017] A light-emitting element formed by a micro-LED array having a (a≥2) micro-LEDs, and

[0018] A light-receiving element formed by an array of photodiodes having a or more photodiodes.

[0019] The plastic optical fiber cable also has a cover layer on the outside of the plastic optical fiber, which is formed by two or more cores and a first sheath surrounding the cores.

[0020] Of the two or more cores, b (a≤b) or more are effective cores for receiving light from the light-emitting element.

[0021] The core is formed of acrylic resin.

[0022] The static bending loss of the plastic optical fiber cable with a bending radius r=3mm is less than 0.2dB. [2]

[0024] According to the optical fiber communication system described above [1], wherein a and b satisfy 2a≤b≤40a. [3]

[0026] According to the optical fiber communication system described above [1], wherein a and b satisfy 3a≤b≤10a. [4]

[0028] According to the optical fiber communication system described above [1], wherein a and b satisfy 3a≤b≤5a. [5]

[0030] According to any one of the aforementioned optical fiber communication systems [1] to [4], the average thickness of the first sheath is 0.5 μm to 5 μm. [6]

[0032] According to any one of the aforementioned optical fiber communication systems [1] to [5], the cross-sectional area ratio (core / first sheath) of the core to the first sheath is 99 / 1 to 70 / 30. [7]

[0034] According to any one of the aforementioned optical fiber communication systems [1] to [6], the first sheath is formed of one or more resins selected from the group consisting of (1) tetrafluoroethylene-vinylidene fluoride copolymer, (2) fluorinated methacrylate polymer, and (3) ethylene-tetrafluoroethylene copolymer. [8]

[0036] The optical fiber communication system according to any one of [1] to [7] above has a second sheath surrounding the first sheath.

[0037] The second sheath is formed of a fluoropolymer resin that is different from the resin constituting the first sheath. [9]

[0039] The optical fiber communication system according to any one of [1] to [7] above has a second sheath surrounding the first sheath.

[0040] The second sheath is formed of a non-fluorinated resin that is different from the resin constituting the first sheath.

[10]

[0042] According to the optical fiber communication system described above [8], the refractive index of the second sheath is lower than that of the first sheath.

[11]

[0044] According to the optical fiber communication system described above [9], the refractive index of the second sheath is lower than that of the first sheath.

[12]

[0046] According to any one of the aforementioned optical fiber communication systems [1] to

[11] , each of the cores has its own independent third sheath.

[13]

[0048] According to any one of the aforementioned optical fiber communication systems [1] to

[12] , the refractive index (n) of the first sheath is 1.38 ≤ n ≤ 1.48.

[14]

[0050] According to any one of the preceding [1] to

[13] optical fiber communication systems, wherein the cover layer is formed of a resin selected from the group consisting of polyethylene resin, flame-retardant polyethylene resin, polyamide resin and vinyl chloride resin.

[15]

[0052] A plastic optical fiber cable, which is a plastic optical fiber cable for use in optical fiber communication systems.

[0053] The optical fiber communication system comprises: a plastic optical fiber cable, a light-emitting element formed by a micro-LED array having a (a≥2) micro-LEDs, and a light-receiving element formed by a photodiode array having a or more photodiodes.

[0054] The plastic optical fiber cable has a plastic optical fiber formed by two or more cores and a first sheath surrounding the cores, and has a cover layer on the outside of the plastic optical fiber.

[0055] Of the two or more cores, b (a≤b) or more are effective cores for receiving light from the light-emitting element.

[0056] The core is formed of acrylic resin.

[0057] The static bending loss of the plastic optical fiber cable with a bending radius r=3mm is less than 0.2dB.

[16]

[0059] An active optical cable carrying an optical fiber communication system as described in any one of [1] to

[14] .

[0060] The effects of the invention

[0061] According to the present invention, an optical fiber communication system is provided that uses a micro-LED array with micro-LEDs as a light-emitting element and a photodiode array as a light-receiving element. The optical fiber communication system has excellent mechanical strength resistance to bending, few communication errors, and excellent cost reduction of the plastic optical fiber cable. Attached Figure Description

[0062] Figure 1 This is a schematic structural diagram of an example of the optical fiber communication system of this embodiment.

[0063] Figure 2 This is a schematic diagram of an example of the transceiver components that make up an optical fiber communication system.

[0064] Figure 3 This is a schematic cross-sectional view of an example of a plastic optical fiber cable.

[0065] Figure 4 This is a schematic cross-sectional view of another example of a plastic optical fiber cable.

[0066] Figure 5 This is a schematic cross-sectional view of another example of a plastic optical fiber cable.

[0067] Figure 6This is a schematic cross-sectional view of another example of a plastic optical fiber cable. Detailed Implementation

[0068] Hereinafter, a method for carrying out the present invention (hereinafter referred to as "this embodiment") will be described in detail with reference to the accompanying drawings, but the present invention is not limited to the following embodiment. The present invention can be implemented in various modifications within the scope of its spirit.

[0069] [Fiber Optic Communication System]

[0070] The optical fiber communication system of this embodiment has:

[0071] Plastic fiber optic cables

[0072] A light-emitting element formed by a micro-LED array having a (a≥2) micro-LEDs, and

[0073] A light-receiving element formed by an array of photodiodes having a or more photodiodes.

[0074] The plastic optical fiber cable has a covering layer on the outside of the plastic optical fiber formed by two or more cores and a first sheath layer surrounding the cores, wherein b (a≤b) or more of the two or more cores are effective cores for receiving light from the light-emitting element, and the cores are formed of acrylic resin.

[0075] The static bending loss of the plastic optical fiber cable with a bending radius r=3mm is less than 0.2dB.

[0076] The term "effective core" as used above refers to the core that receives light emitted by the light-emitting element when using the optical fiber communication system of this embodiment for optical communication. Depending on the combination of their sizes, there may be cores in the light-emitting element, light-receiving element, and plastic optical fiber cable that are not used for communication when using the optical fiber communication system of this embodiment for optical communication; however, such unused cores are not considered "effective cores."

[0077] Based on the above structure, an optical fiber communication system with plastic optical fiber cable can be provided, which has excellent strength resistance to bending, excellent reduction of bending loss, few communication errors, and excellent cost reduction.

[0078] Figure 1 A schematic diagram illustrating an example of the optical fiber communication system of this embodiment.

[0079] Figure 1The optical fiber communication system shown has transceiver units A and B at both ends of a plastic optical fiber cable (hereinafter, sometimes referred to as the plastic optical fiber cable of this embodiment) 10 having two or more cores. The transceiver units A and B convert the specified data into light and perform the transmission and reception of the light and data.

[0080] Transceiver units A and B each have transceiver elements 1 and 2 on a specified Si substrate. The transceiver elements 1 and 2 have light-emitting elements formed by a micro LED array and light-receiving elements formed by a photodiode array.

[0081] like Figure 2 As shown, transceiver elements 1 and 2 respectively have: a light-emitting element 3 (3') formed by a micro-LED array having a (a≥2) micro-LEDs, and a light-receiving element 4 (4') formed by a photodiode array having a or more photodiodes.

[0082] It should be noted that the light-emitting element of transceiver element 1 is set to 3, and the light-receiving element is set to 4. In addition, the light-emitting element of transceiver element 2 is set to 3', and the light-receiving element is set to 4'.

[0083] In addition, IC chips 5 and 6, which have the function of converting specified data into light, are respectively mounted on the Si substrate.

[0084] In an optical fiber communication system, the IC chip 5 on the transceiver A side converts the specified data into light. The light emitted from the light-emitting element 3, formed by a micro-LED array, is transmitted via a specified light refraction device 7 and along the plastic optical fiber cable 10 to the light-receiving element 4', formed by a photodiode array, on the transceiver B side. Similarly, from the transceiver B side, the IC chip 6 converts the specified data into light, and the light emitted from the light-emitting element 3', formed by the micro-LED array, is transmitted via a specified light refraction device 8 and along the plastic optical fiber cable 10 to the light-receiving element 4', formed by a photodiode array, on the transceiver 1 side.

[0085] It should be noted that the optical fiber communication system in this embodiment is not limited to... Figure 1 The structure shown. Figure 1 The diagram shows a single plastic optical fiber cable 10, but it can also be configured to have two or more plastic optical fiber cables 10.

[0086] Specifically, when there are two plastic optical fiber cables, the structure can be configured as follows: the first plastic optical fiber cable connects the light-emitting element 3 of the transceiver element 1 to the light-receiving element 4' of the transceiver element 2, and the second plastic optical fiber cable connects the light-receiving element 4 of the transceiver element 1 to the light-emitting element 3' of the transceiver element 2.

[0087] By setting the plastic optical fiber cable to a single core, the overall structure of the optical fiber communication system is simplified. However, to ensure the desired communication volume, the number of cores in the plastic optical fiber cable needs to be increased, requiring high transmission performance.

[0088] On the other hand, by setting the plastic optical fiber cable 10 to a structure of 2 strands, the overall structure of the optical fiber communication system becomes more complex, but the desired communication volume can be ensured with half the number of cores of the plastic optical fiber cable in the case of 1 strand.

[0089] Furthermore, the transceiver elements 1 and 2 constituting the optical fiber communication system of this embodiment are not limited to... Figure 2 The structure shown is as follows: Figure 2 As shown, a light-emitting element 3 (3') and a light-receiving element 4 (4') can be included in one chip, or the light-emitting element and the light-receiving element can be mounted on different chips.

[0090] The optical fiber communication system of this embodiment has a light-emitting element formed by a micro-LED array having a (a≥2) micro-LEDs and a light-receiving element formed by a or more photodiode arrays. Furthermore, the plastic optical fiber cable has b (a≤b) or more effective cores. Therefore, it can convert a large amount of data corresponding to the desired amount of data to be communicated into light and transmit and receive it in a short time. This enables data transmission and reception in a short time and with low power consumption, thus reducing costs.

[0091] From the viewpoint of transmitting and receiving communication data at high speed and low cost, the number of miniature LEDs 3 constituting the optical fiber communication system of this embodiment, a (a≥2), and the number of effective cores constituting the plastic optical fiber cable 10, b (a≤b), preferably satisfy 2a≤b≤40a, more preferably satisfy 3a≤b≤10a, and even more preferably satisfy 3a≤b≤5a.

[0092] Setting it to 2a≤b reduces the burden of precise alignment when assembling plastic fiber optic cables and transceiver components. Setting it to 3a≤b further reduces crosstalk.

[0093] On the other hand, the greater the number of effective cores, the more light is blocked by the sheath of the plastic optical fiber cable, the less incident light is, and the shorter the communication distance. Therefore, b≤40a is preferred, b≤10a is more preferred, and b≤5a is even more preferred.

[0094] (Plastic fiber optic cable)

[0095] The plastic optical fiber cable of this embodiment is a plastic optical fiber cable used in an optical fiber communication system, which has: a light-emitting element formed by a micro-LED array having a (a≥2) micro-LEDs and a light-receiving element formed by a photodiode array having a or more photodiodes.

[0096] The plastic optical fiber cable of this embodiment is a multi-core optical fiber cable with two or more cores, and a cover layer is also provided on the outside of the plastic optical fiber formed by a first sheath layer surrounding the cores. Preferably, the first sheath layer surrounds the two or more cores, and furthermore, the refractive index of the first sheath layer is lower than the refractive index of the cores.

[0097] Of the two or more cores, b (a≤b) or more are effective cores for receiving light from the light-emitting element.

[0098] Figure 3 A schematic cross-sectional view showing an example of the plastic optical fiber cable of this embodiment.

[0099] like Figure 3 As shown, the plastic optical fiber cable 10 of this embodiment is a multi-core optical fiber cable with multiple cores 11.

[0100] Figure 3 The plastic optical fiber cable 10 shown has 7 cores, but this embodiment is not limited to this example.

[0101] The plastic optical fiber cable 10 is multi-core because the cores 11 are covered by the first sheath layer 12. That is, the first sheath layer 12 surrounds two or more cores 11 as a whole and the surrounding area of ​​each core 11. A covering layer 14 is formed on the outer periphery of the first sheath layer 12.

[0102] In this case, the fiber optic cable, including the core 11 and the first sheath 12, is referred to as plastic optical fiber 13.

[0103] An outer cover layer (not shown) can also be further provided around the outer periphery of the cover layer 14. This provides more reliable protection for the plastic optical fiber 13 from the effects of long-term outdoor use and contact with chemicals, etc.

[0104] <core>

[0105] The diameter of the cross-section of each core 11 of the plastic optical fiber cable constituting this embodiment is preferably 5 to 500 μm, more preferably 10 to 200 μm, even more preferably 20 to 100 μm, and even more preferably 20 to 50 μm.

[0106] If the core diameter is 5 μm or more, it tends to enable the light-receiving element to receive light emitted by the light-emitting element with low loss, and to extend the communication distance. In addition, when the core diameter is 500 μm or less, it tends to suppress the reduction of transmitted light caused by bending, and to ensure sufficient communication distance even in a bent state.

[0107] From the viewpoint of producing a material with good transparency and low light attenuation, the core resin of the core 11 used in plastic optical fiber is an acrylic resin.

[0108] Polymethyl methacrylate (PMMA) resins are preferred as the core resin.

[0109] Polymethyl methacrylate resins refer to homopolymers of methyl methacrylate or copolymers containing more than 50% by mass of methyl methacrylate.

[0110] Polymethyl methacrylate (PMMA) resins can be copolymers comprising methyl methacrylate and components capable of copolymerizing with methyl methacrylate. Components capable of copolymerizing with methyl methacrylate are not limited to the following, but may include, for example, acrylates such as methyl acrylate, ethyl acrylate, and butyl acrylate; methacrylates such as ethyl methacrylate, propyl methacrylate, and cyclohexyl methacrylate; maleimides such as isopropyl maleimide; acrylic acid; methacrylic acid; and styrene.

[0111] These resins can be used alone or in combination of two or more.

[0112] From the viewpoint of melt flow (ease of molding), the molecular weight of acrylic resin, expressed as weight-average molecular weight (Mw), is preferably 80,000 to 200,000, and more preferably 90,000 to 120,000.

[0113] <First sheath>

[0114] In the aforementioned plastic optical fiber cable, the first sheath layer 12 completely surrounds two or more cores 11 and the surrounding area of ​​the cores 11, and the refractive index of the first sheath layer 12 is smaller than that of the resin of the cores.

[0115] By providing a first sheath 12, and by using reflection at the interface between the first sheath 12 and the core 11, the optical signal can still be transmitted within the cable even if the plastic optical fiber cable is bent.

[0116] The resin used for the first sheath 12 can be any resin known in the conventional sense, as long as it has a lower refractive index than the core resin.

[0117] The smaller the difference in refractive index between the core resin and the resin of the first sheath layer, the better it is able to transmit high-frequency signals, but it tends to become more brittle when the cable is bent. On the other hand, the greater the difference in refractive index between the core resin and the resin of the first sheath layer, the stronger the resistance to bending of the cable, but it tends to make it difficult for high-frequency light to pass through. Regarding the resin of the first sheath layer 12, from the viewpoints of being able to transmit high-frequency signals, enhancing the resistance to bending of the cable, and balancing these two characteristics, the refractive index (n) of the resin of the first sheath layer 12 is preferably 1.38≤n≤1.48, more preferably 1.40≤n≤1.48, and even more preferably 1.41≤n≤1.48.

[0118] The resin used as the first sheath layer 12 is not limited to the following, and examples include fluoropolymers. By using a fluoropolymer in the first sheath layer 12, transport loss can be further suppressed.

[0119] Examples of fluoropolymers include fluorinated methacrylate polymers and polyvinylidene fluoride resins.

[0120] As a fluorinated methacrylate polymer, it is not limited to the following, but from the viewpoint of high transmittance, excellent heat resistance, and formability, fluorinated acrylate monomers or methacrylate monomers such as fluoroalkyl methacrylate, fluoroalkyl acrylate, and α-fluoro-perfluoroalkyl acrylate are preferred. Alternatively, it may be a copolymer comprising units derived from fluorinated (meth)acrylate monomers and units derived from other components that can copolymerize with them, preferably a copolymer with units derived from hydrocarbon monomers that can copolymerize with methyl methacrylate. By producing a copolymer of units derived from fluorinated (meth)acrylate monomers and units derived from hydrocarbon monomers that can copolymerize with them, the refractive index can be controlled, and therefore it is preferred.

[0121] On the other hand, as a polyvinylidene fluoride (PVDF) based resin, it is not limited to the following, but from the viewpoint of excellent heat resistance and formability, a homopolymer of PVDF is preferred; a copolymer of PVDF with at least one monomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, trifluoroethylene, hexafluoroacetone, perfluoroalkyl vinyl ether, trifluorochloroethylene, ethylene, and propylene; or an alloy of a polymer containing units derived from these PVDF components with a PMMA-based resin.

[0122] The resin used as the first sheath layer 12 is particularly preferably formed from one or more resins selected from the group consisting of (1) tetrafluoroethylene-vinylidene fluoride copolymer, (2) fluorinated methacrylate polymer, and (3) ethylene-tetrafluoroethylene copolymer. By using these resins, high-frequency signals can be transmitted, and sufficient strength against cable bending can be ensured, thus balancing the characteristics of both.

[0123] Since it is necessary to reduce crosstalk, the average thickness of the first sheath layer 12 is preferably 0.5 μm or more, and from the viewpoint of ensuring sufficient incident light, it is preferably 5 μm or less. More preferably, it is 1.0 μm to 4.0 μm, and even more preferably, it is 1.0 μm to 3.0 μm.

[0124] The average thickness of the first sheath layer 12 can be controlled to the above-mentioned range by adjusting the amount of resin in the first sheath layer during the manufacturing process of the plastic optical fiber cable of this embodiment.

[0125] In addition, there is no particular limitation on the ratio of core resin to resin in the first sheath layer. However, the more core resin there is, the greater the amount of incident light and the longer the communication distance. Conversely, as the diameter of the plastic optical fiber 13 becomes thinner, the thickness of the first sheath layer between the cores will become thinner, crosstalk will increase, and communication errors will increase (BER will decrease).

[0126] From this perspective, the cross-sectional area ratio (core / first sheath) of the core to the first sheath is preferably 99 / 1 to 70 / 30, more preferably 98 / 2 to 80 / 20, and even more preferably 98 / 2 to 85 / 15.

[0127] The cross-sectional area ratio of the core to the first sheath (core / first sheath) can be controlled to the above-mentioned range by adjusting the amount of core resin and first sheath resin in the core resin distribution chamber and sheath resin distribution chamber of the core composite spinning mold in the manufacturing process of plastic optical fiber.

[0128] <Second sheath>

[0129] The plastic optical fiber cable of this embodiment is as follows: Figure 4 As shown, a second sheath layer 15, made of a resin different from the resin constituting the first sheath layer 12, can be formed outside the aforementioned first sheath layer 12 in a manner that surrounds the first sheath layer 12. The refractive index of the second sheath layer 15 is preferably lower than that of the first sheath layer 12. Through reflection at the interface between the second sheath layer 15 and the first sheath layer 12, the optical signal is transmitted within the cable even if it is bent.

[0130] The second sheath 15 has the function of protecting the plastic optical fiber 13 and maintaining its mechanical strength.

[0131] The resin of the second sheath 15 can be any resin different from the resin of the first sheath 12, and there is no particular limitation. As a preferred example, a fluoropolymer resin that has a strong adhesion to the resin of the first sheath can be cited.

[0132] Examples of such fluororesins include those applicable to the first sheath 12, which are different from the resin constituting the first sheath 12.

[0133] In particular, when the first sheath 12 is formed of one or more resins selected from the group consisting of (1) tetrafluoroethylene-vinylidene fluoride copolymer, (2) fluorinated methacrylate polymer and (3) ethylene-tetrafluoroethylene copolymer, from the viewpoint of mechanical strength, the second sheath 15 is particularly preferably the aforementioned resin (1) or (3).

[0134] Alternatively, a non-fluorinated resin other than the aforementioned fluorinated resin can be used as the resin for the second sheath 12.

[0135] As for the aforementioned non-fluorinated resins, acrylic resins are preferred, for example, from the viewpoint of mechanical strength.

[0136] The resin used as the second sheath layer 12 can be a single type or a combination of two or more types. Polymethyl methacrylate resins are particularly preferred.

[0137] Polymethyl methacrylate resins refer to homopolymers of methyl methacrylate or copolymers containing more than 50% by mass of methyl methacrylate.

[0138] Polymethyl methacrylate (PMMA) resins can be copolymers comprising methyl methacrylate and components capable of copolymerizing with methyl methacrylate. Components capable of copolymerizing with methyl methacrylate are not limited to the following, but may include, for example, acrylates such as methyl acrylate, ethyl acrylate, and butyl acrylate; methacrylates such as ethyl methacrylate, propyl methacrylate, and cyclohexyl methacrylate; maleimides such as isopropyl maleimide; acrylic acid; methacrylic acid; and styrene.

[0139] These copolymerizable components can be used alone or in combination of two or more.

[0140] From the viewpoint of melt flow (ease of molding), the molecular weight of the acrylic resin used as the second sheath layer 12, measured in terms of weight-average molecular weight (Mw), is preferably 80,000 to 200,000, and more preferably 90,000 to 120,000.

[0141] From the viewpoint of maintaining mechanical strength, the thickness of the second sheath 15 is preferably 5 μm or more, and from the viewpoint of the assemblability of the communication system and ease of alignment between the plastic optical fiber cable and the transceiver components, it is preferably 100 μm or less. More preferably, it is 7 to 50 μm, and even more preferably, it is 10 to 40 μm.

[0142] <Third sheath>

[0143] like Figure 5 , Figure 6 As shown, each core 11 of the plastic optical fiber cable in this embodiment can also be covered by an independent third sheath layer 16.

[0144] It should be noted that the core 11 having a third sheath 16 is not limited to the aforementioned effective core.

[0145] The cores 11 of the plastic optical fiber cable 10 are each covered by a third sheath layer 16, and are multi-core by covering them with a first sheath layer 12.

[0146] exist Figure 5 The plastic optical fiber 13 comprises a core 11, a first sheath 12, and a third sheath 16.

[0147] exist Figure 6 The optical fiber 13 comprises a core 11, a first sheath 12, a second sheath, and a third sheath 16.

[0148] The resin of the third sheath layer 16 can be any resin with a lower refractive index than the core resin and different from the resin of the first sheath layer 12, and there are no particular limitations. From the viewpoint of having a stronger adhesion with the resin of the first sheath layer 12, a fluoropolymer resin is preferred.

[0149] Examples of such fluororesins include those applicable to the first sheath 12, which are different from the resin in the first sheath.

[0150] In particular, when the first sheath 12 is formed of one or more resins selected from the group consisting of (1) tetrafluoroethylene-vinylidene fluoride copolymer, (2) fluorinated methacrylate polymer and (3) ethylene-tetrafluoroethylene copolymer, from the viewpoint of mechanical strength, the third sheath 16 is particularly preferably the aforementioned resin (1) or (3).

[0151] <Overlay>

[0152] like Figures 3-6 As shown, the plastic optical fiber cable of this embodiment has a covering layer 14 on the outside of the plastic optical fiber 13.

[0153] As the constituent material of the cover layer 14, any resin is acceptable and there is no particular limitation. From the viewpoint of protecting the plastic optical fiber cable of this embodiment, resins with excellent mechanical strength and flame retardant properties are preferred, and resins with excellent mechanical strength are particularly preferred.

[0154] Resins with excellent mechanical strength, not limited to the following, include, for example, polyamide resins, polyethylene resins, polypropylene resins, and polyvinylidene fluoride resins. These resins tend to protect plastic optical fiber cables from external forces such as lateral pressure and also mitigate external impacts. For protection against external forces, the resin constituting the cover layer 14 preferably has sufficient strength, and particularly preferably a tensile yield strength (JIS K7113) of 20 MPa or higher. Examples of resins with such strength include, for example, polyamide 12 resins, cross-linked polyethylene resins, and polypropylene resins.

[0155] On the other hand, the resin, which is flame-retardant, is preferably formed from a resin composition that conforms to the UL VW-1 standard. By using such a resin composition for the cover layer 14, plastic optical fiber cables with less deterioration in transmission loss under high-temperature environments can be obtained.

[0156] As can be inferred from the following, compliance with the UL VW-1 standard is useful in preventing the deterioration of transmission loss under high-temperature conditions.

[0157] That is, it is generally assumed that resins with high flame retardancy have high heat resistance, and it is believed that having flame retardancy that happens to meet this standard helps to improve the heat resistance of plastic optical fiber cables. Therefore, the resin material of the covering layer used in the plastic optical fiber cable constituting this embodiment preferably conforms to the UL VW-1 standard.

[0158] Examples of resin materials used in the coating layer include polyethylene resins, flame-retardant polyethylene resins, polyamide resins, vinyl chloride resins, polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and other fluororesins; and silicone resins.

[0159] In particular, from the viewpoint of being halogen-free and environmentally friendly, flame-retardant polyethylene resins that have been blended with flame-retardant materials to impart flame retardancy are preferred.

[0160] As a flame-retardant polyethylene resin, it is not limited to the following, but preferably includes, for example, at least one copolymer selected from the group consisting of ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, and ethylene-ethyl acrylate copolymer, (B) high-density polyethylene modified with unsaturated carboxylic acid or its derivative, (C) magnesium hydroxide and (D) red phosphorus.

[0161] Furthermore, from the viewpoint of further improving flame retardancy, it is more preferable to include (E) melamine isocyanurate.

[0162] In addition, from the viewpoint of improving heat resistance, polyamide resins are preferred.

[0163] Examples of polyamide resins include polyamide 66, polyamide 6, polyamide 11, polyamide 12, and polyamide 10-10. Among these, polyamide 11 and polyamide 12 resins are preferred due to their excellent heat resistance. Furthermore, polyamide 10-10 resins can be manufactured from plant-based raw materials such as castor oil, which is preferred from the perspective of reducing carbon dioxide emissions.

[0164] <Other Ingredients>

[0165] The various parts of the plastic optical fiber cable constituting this embodiment may further contain prescribed additives without impairing the effect of this embodiment.

[0166] The additive can be selected according to its intended use and is not limited to the following substances, such as colorants like carbon black, antioxidants, ultraviolet absorbers, light stabilizers, metal passivators, lubricants, flame retardants, flame retardant additives, fillers, etc.

[0167] As an example of the use of additives, carbon black can be added to the first to third sheath layers and the cover layer for the purpose of preventing light leakage from the plastic optical fiber used for communication purposes.

[0168] (Other structures)

[0169] As described above, the plastic optical fiber cable of this embodiment includes: a plastic optical fiber having one or more cores and a first sheath layer consisting of at least one layer formed on the outer periphery of the cores; and a cover layer formed on the outer periphery of the plastic optical fiber.

[0170] The plastic optical fiber cable of this embodiment may further have an outer cover layer described later, and the number of lines may also be appropriately selected.

[0171] <Outer Covering Layer>

[0172] The plastic optical fiber cable of this embodiment can use the above-described cover layer as the outermost layer, but it can also be further reinforced by applying an outer cover layer (also called an "outer sheath") made of thermoplastic resins such as nylon 12, soft nylon, polyethylene, polyvinyl chloride, polypropylene, and fluoropolymer.

[0173] Alternatively, the plastic optical fiber cable of this embodiment can be covered together with other materials such as plastic optical fiber cables, metal cables, and reinforcing materials, using an outer cover layer to form a composite cable.

[0174] (Physical properties of plastic optical fiber cables)

[0175] <Static Bending Loss>

[0176] Regarding the plastic optical fiber cable of this embodiment, from the viewpoints of excellent strength resistance to bending, superior reduction of bending loss, and suppression of communication errors, the stationary bending loss at a bending radius r = 3 mm is 0.2 dB or less. Specifically, when bent at 90 degrees along a cylinder with a radius of 3 mm, the difference in light intensity before and after bending is 0.2 dB or less. Preferably, it is 0.15 dB or less, and more preferably 0.1 dB or less.

[0177] The static bending loss of plastic optical fiber cables can be controlled to the above-mentioned range by adjusting the diameter of the core and the refractive index of each sheath layer of the optical fiber cable.

[0178] [Manufacturing method of plastic optical fiber cables]

[0179] The manufacturing method of the plastic optical fiber cable in this embodiment is not particularly limited and can be carried out by known methods.

[0180] For example, a preferred method is to form a cover layer on the outside of a plastic optical fiber manufactured using a known composite spinning method. This cover layer is formed from the aforementioned polyethylene resin, polyvinyl chloride, polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and silicone resin, which are thermally melted by a crosshead die.

[0181] [Active Optical Cable]

[0182] The fiber optic communication system of this embodiment can be mounted on an active optical cable (AOC) for use. Therefore, a short-distance optical communication system capable of rapidly transmitting large amounts of information can be easily applied to various servers, etc.

[0183] Example

[0184] The following specific embodiments and comparative examples illustrate this implementation method in detail, but the form of the present invention is not limited to the following embodiments.

[0185] It should be noted that the physical property values ​​used in this specification, as well as the evaluated physical property values ​​evaluated in the following examples and comparative examples, are based on the measurement and evaluation methods shown below.

[0186] [Physical Properties of Plastic Fiber Optic Cables]

[0187] (Static bending loss)

[0188] For each embodiment and comparative example, the difference in light intensity before and after bending along a cylinder with a radius of 3 mm to 90 degrees was measured as the static bending loss.

[0189] When the measured value is below 0.2 dB, it is regarded as qualified.

[0190] [Evaluation of Optical Fiber Communication System]

[0191] (Judgment of Communication Ability)

[0192] As the light-emitting element, a micro-LED array with 256 elements (a = 256) arranged at intervals of 30 μm is used.

[0193] As the light-receiving element, a silicon photodiode array with x photodiodes arranged is used.

[0194] Data divided into x is generated by "FPGA manufactured by Xilinx", communicated at a speed of 2 Gb / s per channel, and the bit error rate (BER) is measured.

[0195] If the measurement result is greater than 10 -10 , it is regarded as defective (unqualified). If it is 10 -10 ~10 -12 , it is regarded as good (qualified). If it is less than 10 -12 , it is regarded as excellent (qualified).

[0196] [Example 1]

[0197] Polymethyl methacrylate (refractive index 1.491) is used as the resin constituting the core (core resin), and tetrafluoroethylene - vinylidene fluoride copolymer (refractive index 1.40) is used as the resin constituting the first sheath layer (sheath resin). It is put into the core resin distribution chamber and the sheath resin distribution chamber of a 613-core composite spinning die at a ratio of core / first sheath layer cross-sectional area = 80 / 20, and a plastic optical fiber with a diameter of 1 mm and 613 cores (effective core number b = 512) is manufactured by composite spinning.

[0198] The average thickness of the first sheath layer is 2 μm.

[0199] It should be noted that the refractive index is measured using an Abbe refractometer (manufactured by Atago Co., Ltd., "Abbe refractometer model 1") with a sodium D-ray as the light source in a constant temperature room at 23 °C.

[0200] Furthermore, the spun plastic optical fiber is covered with a covering layer made of polyethylene resin at a forming temperature of 130 °C to 200 °C so that the outer diameter becomes 2.2 mm, and a 613-core plastic optical fiber cable is manufactured.

[0201] The plastic optical fiber cable is bent at a bending radius r = 3 mm by 90°, and the static bending loss is measured. The result is 0.03 dB.

[0202] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 2.0 × 10⁻⁶. -12 It is good.

[0203] [Example 2]

[0204] As a core composite spinning die, a 1303 core composite spinning die is used to manufacture plastic optical fibers with a diameter of 1mm and 1303 cores (effective core number b=1024) through composite spinning.

[0205] The average thickness of the first sheath is 1 μm.

[0206] The plastic optical fiber cable is manufactured under the same conditions as described in [Example 1] above.

[0207] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured, with a result of 0.01dB.

[0208] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 9.1 × 10⁻⁶. -13 It is excellent.

[0209] [Example 3]

[0210] Fluorinated methacrylate polymer (refractive index 1.42) is used as the resin constituting the first sheath layer. A 1303 core composite spinning die is used as the core composite spinning die to manufacture a 1mm diameter 1303 core (effective core number b=1024) plastic optical fiber by composite spinning.

[0211] The average thickness of the first sheath is 1 μm.

[0212] The fiber optic communication system was constructed under the same conditions as in [Example 2] above, and communication tests were conducted.

[0213] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured, with a result of 0.02dB.

[0214] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 8.2 × 10⁻⁶. -13 It is excellent.

[0215] [Example 4]

[0216] The resin constituting the first sheath layer is an ethylene-tetrafluoroethylene copolymer (refractive index 1.39). A 1303 core composite spinning die is used as the core composite spinning die, and a plastic optical fiber with a diameter of 1 mm and 1303 cores (effective core number b=1024) is manufactured by composite spinning.

[0217] The average thickness of the first sheath is 1 μm.

[0218] The fiber optic communication system was constructed under the same conditions as in [Example 2] above, and communication tests were conducted.

[0219] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured, with a result of 0.01dB.

[0220] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 9.8 × 10⁻⁶. -13 It is excellent.

[0221] [Example 5]

[0222] As a core composite spinning die, a 3505 core composite spinning die is used to manufacture plastic optical fibers with a diameter of 2.5 mm and 3505 cores (effective core number b=2560) through composite spinning.

[0223] The average thickness of the first sheath is 0.8 μm.

[0224] The plastic optical fiber cable is manufactured under the same conditions as described in [Example 1] above.

[0225] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured, with a result of 0.1dB.

[0226] A fiber optic communication system was constructed, consisting of a 10m plastic optical fiber cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 7.8 × 10⁻⁶. -13 It is excellent.

[0227] [Example 6]

[0228] The cross-sectional area ratio (core / first sheath) of the core to the first sheath is set to 90 / 10.

[0229] Plastic optical fibers with a diameter of 1 mm and 1303 cores (effective core number b=1024) are manufactured by composite spinning.

[0230] The average thickness of the first sheath is 0.8 μm.

[0231] The plastic optical fiber cable is manufactured under the same conditions as described in [Example 2] above.

[0232] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured, with a result of 0.01dB.

[0233] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 9.2 × 10⁻⁶. -13 It is excellent.

[0234] [Example 7]

[0235] The cross-sectional area ratio (core / first sheath) of the core to the first sheath is set to 60 / 40, and a plastic optical fiber with a diameter of 1 mm and 613 cores (effective core number b=512) is manufactured by composite spinning.

[0236] The average thickness of the first sheath is 4 μm.

[0237] The plastic optical fiber cable is manufactured under the same conditions as described in [Example 1] above.

[0238] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured, with a result of 0.03dB.

[0239] A fiber optic communication system was constructed, consisting of a 10m plastic optical fiber cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 5.0 × 10⁻⁶. -12 It is good.

[0240] [Example 8]

[0241] The resin constituting the first sheath layer is a fluorinated methacrylate polymer (refractive index 1.42), and the plastic optical fiber cable is manufactured under the same conditions as described in [Example 5].

[0242] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured, with a result of 0.1dB.

[0243] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 5.2 × 10⁻⁶. -13 It is excellent.

[0244] [Example 9]

[0245] As a core composite spinning die, a 3505 core composite spinning die is used to manufacture plastic optical fibers with a diameter of 1.8 mm and 3505 cores (effective core number b=2560) through composite spinning.

[0246] The average thickness of the first sheath is 1.0 μm.

[0247] The plastic optical fiber cable is manufactured under the same conditions as described in [Example 1] above.

[0248] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured. The result was less than 0.1dB.

[0249] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 6.8 × 10⁻⁶. -13 It is excellent.

[0250] [Example 10]

[0251] Polyamide 12 resin was used as the covering material. The plastic optical fiber cable was manufactured under the same conditions as in [Example 9].

[0252] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured. The result was less than 0.1dB.

[0253] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 6.8 × 10⁻⁶. -13 It is excellent.

[0254] [Example 11]

[0255] Flame-retardant polyethylene resin was used as the material for the covering layer. The plastic optical fiber cable was manufactured under the same conditions as in [Example 9].

[0256] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured. The result was less than 0.1dB.

[0257] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 6.8 × 10⁻⁶. -13 It is excellent.

[0258] [Example 12]

[0259] As a core composite spinning die, a 7375 core composite spinning die is used to manufacture plastic optical fibers with a diameter of 1.8 mm and 7375 cores (effective core number b=5380) through composite spinning.

[0260] The average thickness of the first sheath is 1.0 μm.

[0261] The plastic optical fiber cable is manufactured under the same conditions as described in [Example 1] above.

[0262] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured. The result was less than 0.1dB.

[0263] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 5.9 × 10⁻⁶. -13 It is excellent.

[0264] [Example 13]

[0265] As a core composite spinning die, a 13003 core composite spinning die is used to manufacture plastic optical fibers with a diameter of 1.8 mm and 13003 cores (effective core number b=9500) through composite spinning.

[0266] The average thickness of the first sheath is 1.0 μm.

[0267] The plastic optical fiber cable is manufactured under the same conditions as described in [Example 1] above.

[0268] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured. The result was less than 0.1dB.

[0269] A fiber optic communication system was constructed, consisting of a 10m plastic optical fiber cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 5.7 × 10⁻⁶. -13 It is excellent.

[0270] [Example 14]

[0271] A 3505-core multilayer composite spinning die was used as the core composite spinning die to manufacture 1.8 mm diameter 3505-core (effective core number b=2560) plastic optical fibers with a second sheath. A fluorinated methacrylate polymer (refractive index 1.42) was used as the resin constituting the first sheath, and a tetrafluoroethylene-vinylidene fluoride copolymer (refractive index 1.40) was used as the resin constituting the second sheath.

[0272] The average thickness of the first sheath is 1.0 μm, and the average thickness of the second sheath is 20 μm.

[0273] The plastic optical fiber cable is manufactured under the same conditions as described in [Example 1] above.

[0274] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured. The result was less than 0.1dB.

[0275] A fiber optic communication system was constructed, consisting of a 10m plastic optical fiber cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 5.7 × 10⁻⁶. -13 It is excellent.

[0276] [Example 15]

[0277] A 7375 core composite spinning die was used as the core composite spinning die to manufacture a 1.8 mm diameter plastic optical fiber with a second sheath, consisting of 7375 cores (effective core number b=5380). A fluorinated methacrylate polymer (refractive index 1.42) was used as the resin constituting the first sheath, and a tetrafluoroethylene-vinylidene fluoride copolymer (refractive index 1.40) was used as the resin constituting the second sheath.

[0278] The average thickness of the first sheath is 1.0 μm, and the average thickness of the second sheath is 22 μm.

[0279] The plastic optical fiber cable is manufactured under the same conditions as described in [Example 1] above.

[0280] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured. The result was less than 0.1dB.

[0281] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 5.9 × 10⁻⁶. -12 It is excellent.

[0282] [Example 16]

[0283] A 13003 core composite spinning die was used as the core composite spinning die to manufacture a plastic optical fiber with a diameter of 1.8 mm and an effective core number b=9500, having a second sheath layer, by composite spinning. A fluorinated methacrylate polymer (refractive index 1.42) was used as the resin constituting the first sheath layer, and a tetrafluoroethylene-vinylidene fluoride copolymer (refractive index 1.40) was used as the resin constituting the second sheath layer.

[0284] The average thickness of the first sheath is 1.0 μm, and the average thickness of the second sheath is 21 μm.

[0285] The plastic optical fiber cable is manufactured under the same conditions as described in [Example 1] above.

[0286] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured. The result was less than 0.1dB.

[0287] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 5.8 × 10⁻⁶. -13 It is excellent.

[0288] [Example 17]

[0289] A 3505-core multilayer composite spinning die was used as the core composite spinning die to manufacture 1.8 mm diameter 3505-core (effective core number b=2560) plastic optical fibers with a second and third sheath layer through composite spinning. A fluorinated methacrylate polymer (refractive index 1.42) was used as the resin constituting the first sheath layer, and a tetrafluoroethylene-vinylidene fluoride copolymer (refractive index 1.40) was used as the resin constituting the second and third sheath layers.

[0290] The average thickness of the first sheath is 1.0 μm, the average thickness of the second sheath is 20 μm, and the average thickness of the third sheath is 1.0 μm.

[0291] The plastic optical fiber cable is manufactured under the same conditions as described in [Example 1] above.

[0292] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured. The result was less than 0.1dB.

[0293] A fiber optic communication system was constructed, consisting of a 10m plastic optical fiber cable, a communication wavelength of 463nm, a micro LEDs (a=256) as light-emitting elements, and a photodiode array with 256 photodiodes (x=256) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 6.3 × 10⁻⁶. -13 It is excellent.

[0294] [Comparative Example 1]

[0295] As a plastic optical fiber cable, the HMCKU-1000P (19 cores, refractive index of the first sheath layer 1.40) manufactured by Asahi Kasei Corporation is used.

[0296] The plastic optical fiber cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured to be 1.7dB.

[0297] A fiber optic communication system was constructed, consisting of a 10m plastic fiber optic cable, a communication wavelength of 463nm, a miniature LEDs (a=8) as light-emitting elements, and a photodiode array with eight photodiodes (x=8) as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 0.7 × 10⁻⁶. -8 It is good.

[0298] [Comparative Example 2]

[0299] As an optical fiber cable, it uses a bundle of 8 quartz glass fibers.

[0300] The fiber optic cable was bent 90° with a bending radius of r=3mm, and the static bending loss was measured. The result showed that the cable broke.

[0301] A fiber optic communication system was constructed, consisting of a 10m fiber optic cable, a communication wavelength of 463nm, a miniature LEDs (a=8) as light-emitting elements, and a photodiode array with 8 photodiodes as light-receiving elements. Communication tests were conducted, and the bit error rate (BER) was found to be 1.1 × 10⁻⁶. -13 It is good.

[0302] This application is based on Japanese Patent Application No. 2023-180468 filed with the Japan Patent Office on October 19, 2023, the contents of which are incorporated herein by reference.

[0303] Industrial availability

[0304] The plastic optical fiber of the present invention has industrial applicability as a medical endoscope and an industrial endoscope.

[0305] Explanation of reference numerals in the attached figures

[0306] 1,2 Transceiver Components

[0307] 3,3' Light-emitting element

[0308] 4,4' Light-receiving element

[0309] 5,6 IC chips

[0310] 7,8 Light refracting device

[0311] 10 Plastic fiber optic cables

[0312] 11 cores

[0313] 12 First sheath

[0314] 13 Plastic optical fiber

[0315] 14 Covering layer

[0316] 15 Second sheath

[0317] 16 Third sheath

[0318] A, B Receiving and Dispatch Departments

Claims

1. An optical fiber communication system, comprising: Plastic fiber optic cables A light-emitting element formed by a micro-LED array having a (a≥2) micro-LEDs, and A light-receiving element formed by an array of photodiodes having a or more photodiodes. The plastic optical fiber cable also has a cover layer on the outside of the plastic optical fiber, which is formed by two or more cores and a first sheath surrounding the cores. Of the two or more cores, b (a≤b) or more are effective cores for receiving light from the light-emitting element. The core is formed of acrylic resin. The static bending loss of the plastic optical fiber cable with a bending radius r=3mm is less than 0.2dB.

2. The optical fiber communication system according to claim 1, wherein, The conditions a and b satisfy 2a≤b≤40a.

3. The optical fiber communication system according to claim 1, wherein, The condition 'a' and 'b' satisfy 3a ≤ b ≤ 10a.

4. The optical fiber communication system according to claim 1, wherein, The conditions a and b satisfy 3a≤b≤5a.

5. The optical fiber communication system according to claim 1, wherein, The average thickness of the first sheath layer is 0.5 μm to 5 μm.

6. The optical fiber communication system according to claim 1, wherein, The cross-sectional area ratio (core / first sheath) of the core to the first sheath is 99 / 1 to 70 / 30.

7. The optical fiber communication system according to claim 1, wherein, The first sheath is formed of one or more resins selected from the group consisting of (1) tetrafluoroethylene-vinylidene fluoride copolymer, (2) fluorinated methacrylate polymer, and (3) ethylene-tetrafluoroethylene copolymer.

8. The optical fiber communication system according to claim 1, further comprising a second sheath surrounding the first sheath. The second sheath is formed of a fluoropolymer resin that is different from the resin constituting the first sheath.

9. The optical fiber communication system according to claim 1, further comprising a second sheath surrounding the first sheath. The second sheath is formed of a non-fluorinated resin that is different from the resin constituting the first sheath.

10. The optical fiber communication system according to claim 8, wherein, The refractive index of the second sheath is lower than that of the first sheath.

11. The optical fiber communication system according to claim 9, wherein, The refractive index of the second sheath is lower than that of the first sheath.

12. The optical fiber communication system according to claim 1, wherein, Each core has its own independent third sheath.

13. The optical fiber communication system according to claim 1, wherein, The refractive index (n) of the first sheath is 1.38≤n≤1.

48.

14. The optical fiber communication system according to claim 1, wherein, The covering layer is formed from a resin selected from the group consisting of polyethylene resins, flame-retardant polyethylene resins, polyamide resins, and vinyl chloride resins.

15. A plastic optical fiber cable, which is a plastic optical fiber cable for use in optical fiber communication systems. The optical fiber communication system comprises: a plastic optical fiber cable, a light-emitting element formed by a micro-LED array having a (a≥2) micro-LEDs, and a light-receiving element formed by a photodiode array having a or more photodiodes. The plastic optical fiber cable has a plastic optical fiber formed by two or more cores and a first sheath surrounding the cores, and has a cover layer on the outside of the plastic optical fiber. Of the two or more cores, b (a≤b) or more are effective cores for receiving light from the light-emitting element. The core is formed of acrylic resin. The static bending loss of the plastic optical fiber cable with a bending radius r=3mm is less than 0.2dB.

16. An active optical cable carrying the optical fiber communication system according to any one of claims 1 to 14.

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