JP2014013311A - Optical fiber and optical communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber capable of more effectively performing energy transmission in executing optical power supply.SOLUTION: A multi-core optical fiber 17 includes: a communication core 17a for propagating a communication light beam L1 required for communication; energy transmission cores 17b, being cores different from the communication core 17a, for performing energy transmission; and a cladding 17c for covering the communication core 17a and the energy transmission cores 17b. In the multi-core optical fiber 17, a diameter of the energy transmission cores 17b is larger than a diameter of the communication core 17a, and a wavelength λ1 of the communication light beam L1 propagated through the communication core 17a is set so as to be different from a wavelength λ2 of the energy transmission light beam L2 transmitted by the energy transmission cores 17b.

Description

  The present invention relates to an optical fiber and an optical communication system.

  In order to centrally observe predetermined information (for example, current value or voltage value) in a remote place, a measurement signal from a sensor disposed in a remote place is transmitted via an optical fiber, and the predetermined information is collected. Has been done. For example, Patent Document 1 proposes that power is supplied to a sensor used for measurement, a terminal device for optical communication, or the like via an optical fiber.

Japanese Patent No. 4641787

  Incidentally, since the optical power feeding system described in Patent Document 1 uses a single core fiber, it is necessary to perform high energy transmission using a single core that transmits communication light. In some cases, the connection portion was damaged. Further, the capacity of energy to be transmitted has to be limited in consideration of optical communication and the like.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an optical fiber and an optical communication system that can more effectively transmit energy when performing optical power feeding.

  An optical fiber according to the present invention is an optical fiber having a plurality of cores, a communication core for propagating communication light necessary for communication, and a core different from the communication core for energy transmission. A core and a cladding for covering the communication core and the energy transmission core, the diameter of the energy transmission core being larger than the diameter of the communication core, the wavelength of communication light propagating in the communication core and the energy transmission core It is characterized in that the wavelength of the light of energy transmission transmitted in the above is different.

  This optical fiber includes a communication core and an energy transmission core, and the diameter of the energy transmission core is larger than the diameter of the communication core. In this case, since a core is provided for each transmission, both communication and energy transmission can be easily achieved, and the influence of optical power feeding on optical communication can be reduced. Moreover, since the energy transmission core has a large diameter, it is possible to avoid damaging the optical fiber even when energy having a relatively high capacity is incident on the energy transmission core.

  Further, in this optical fiber, the wavelength of communication light propagated in the communication core is different from the wavelength of energy transmission light transmitted in the energy transmission core. In this case, since communication and energy transmission are performed at different wavelengths, it is possible to reduce the mixing of noise into the communication. Thus, according to this optical fiber, it is possible to transmit energy more effectively when performing optical power feeding.

  In the optical fiber according to the present invention, the cross-sectional area of the energy transmission core may be more than twice the cross-sectional area of the communication core, or the cross-sectional area of the energy transmission core is 10 times the cross-sectional area of the communication core. It may be the above. In this case, it is possible to further reduce the damage of the connection portion of the optical fiber by reducing the power density of energy transmission. In the optical fiber according to the present invention, a plurality of energy transmission cores are provided in the optical fiber, and the cross-sectional area of the energy transmission core may be the sum of the cross-sectional areas of the plurality of energy transmission cores.

  In the optical fiber according to the present invention, the energy transmission core may be disposed radially outward from the central axis of the optical fiber with respect to the communication core. In this case, the communication core is disposed on the center side of the optical fiber, and stable information communication can be performed.

  In the optical fiber according to the present invention, the numerical aperture of the energy transmission core may be larger than the numerical aperture of the communication core. In this case, by increasing the numerical aperture of the energy transmission core, light leakage from the bent portion can be reduced even when the optical fiber is bent. Thereby, it is possible to reduce energy loss in the optical power feeding.

  An optical communication system according to the present invention includes an optical fiber and a spatial separation optical system that spatially separates communication light and energy transmission light at at least one of input and output ends of the optical fiber. . As described above, the optical fiber includes a communication core for propagating communication light necessary for communication, an energy transmission core that is different from the communication core and performs energy transmission, a communication core, and energy transmission. The energy transmission core has a larger diameter than the communication core, the wavelength of the communication light transmitted through the communication core, and the energy transmission light transmitted through the energy transmission core. The wavelength is different.

  The optical communication system according to the present invention includes an optical fiber and a wavelength separation optical system that separates communication light and energy transmission light by wavelength at at least one of the input and output ends of the optical fiber. . The optical fiber includes a communication core that propagates communication light necessary for communication, an energy transmission core that is different from the communication core and that transmits energy, and a cladding that covers the communication core and the energy transmission core. The diameter of the energy transmission core is larger than the diameter of the communication core, and the wavelength of the communication light transmitted through the communication core is different from the wavelength of the energy transmission light transmitted through the energy transmission core. It is like that.

  Also in the optical communication system described above, as described above, the optical fiber includes a communication core and an energy transmission core, and the diameter of the energy transmission core is larger than the diameter of the communication core. In this case, since a core is provided for each transmission, both communication and energy transmission can be easily achieved, and the influence of optical power feeding on optical communication can be reduced. Moreover, since the energy transmission core has a large diameter, it is possible to avoid damaging the optical fiber even when energy having a relatively high capacity is incident on the energy transmission core.

  Further, in an optical fiber used in an optical communication system, the wavelength of communication light propagated through the communication core and the wavelength of energy transmission light transmitted through the energy transmission core are different. In this case, since communication and energy transmission are performed at different wavelengths, it is possible to reduce the mixing of noise into the communication. Thus, according to the above optical communication system, it is possible to more effectively transmit energy when performing optical power feeding.

  ADVANTAGE OF THE INVENTION According to this invention, the optical fiber and optical communication system which can transmit energy more effectively when performing optical power feeding can be provided.

It is a figure which shows an example of the optical communication system which concerns on this embodiment. It is a figure which shows the cross section of the multi-core fiber used for the optical communication system shown in FIG. It is a figure which shows an example of the multiplexing apparatus used for the optical communication system shown in FIG. It is a figure which shows an example of the branching apparatus used for the optical communication system shown in FIG. It is a figure which shows another example of the branching apparatus used for the optical communication system shown in FIG. It is a figure which shows the center opening type | mold mirror used for the branching apparatus shown in FIG. It is a figure which shows another example of the branching apparatus used for the optical communication system shown in FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  First, the optical communication system 1 according to the present embodiment will be described with reference to FIGS.

  As shown in FIG. 1, the optical communication system 1 includes a communication light source 11, a feeding light source 12, a multiplexing device 13, a demultiplexing device 14, a sensor device 20, single core fibers 15 a and 15 b (hereinafter “SCF 15 a and 15 b”). ), A multi-core fiber 17 (hereinafter referred to as “MCF17”), and single-core fibers 19a and 19b (hereinafter referred to as “SCF 19a and 19b”). The sensor device 20 includes photoelectric conversion units 21 and 22, a control unit 23, and a power supply 24.

  The communication light source 11 is light for optical communication performed by the optical communication system 1, and is a light source for generating light L1 having a wavelength λ1 (for example, wavelength 1.55 μm). The communication light source 11 includes, for example, a light emitting diode (LED) or a laser diode (LD). The communication light source 11 is connected to one end of the SCF 15a, and the light L1 generated by the communication light source 11 is incident on the multiplexer 13 through the SCF 15a. The SCF 15a is, for example, a single core fiber having a clad diameter of about 125 μm and a core diameter of 10 μm.

  The power supply light source 12 is light for optical power supply executed by the optical communication system 1, and is a light source for generating light L2 having a wavelength λ2 (for example, wavelength 1.45 μm) different from the wavelength λ1. The power supply light source 12 includes, for example, a light emitting diode (LED) or a laser diode (LD). The power supply light source 12 is connected to one end of the two SCFs 15b and 15b, and the light generated by the power supply light source 12 is incident on the multiplexer 13 through the two SCFs 15b and 15b. Each SCF 15b is, for example, a single-core fiber having a clad diameter of about 125 μm and a core diameter of 25 μm. The light L2 generated by the power supply light source 12 corresponds to, for example, power of about 1 mW to 1000 mW.

  As shown in FIG. 3, the multiplexer 13 is a micro optical system (space) for optically coupling the SCF 15 a connected to the communication light source 11 and the SCFs 15 b and 15 b connected to the power supply light source 12 to the MCF 17. (Separation optical system) device, which includes a first optical system S1 and a second optical system S2.

  The first optical system S1 is located on the SCF 15a, 15b side, and is composed of one condenser lens. The condensing lens of the first optical system S1 is disposed so as to face each of the SCFs 15a and 15b on the axis of the exit end of the SCFs 15a and 15b. The condensing lens of the first optical system S1 is disposed at a position away from the emission ends of the SCFs 15a and 15b by a predetermined distance. The plurality of beams transmitted through the condenser lens are reduced in the beam interval toward the second optical system S2 and intersect once at the focal point. Thereafter, the beam interval is expanded again, and the second interval is increased. The light enters the optical system S2.

  The second optical system S2 is located on the MCF 17 side, and is composed of one condenser lens. The condenser lens of the second optical system S2 is disposed so as to face the MCF 17 on the axis of the incident end of the MCF 17. The condenser lens of the second optical system S2 is disposed at a position away from the incident end of the MCF 17 by the focal length of the condenser lens. Then, the second optical system S2 deflects the plurality of beams L1 and L2 transmitted through the condenser lens so as to be parallel to the optical axis of each core of the MCF 17, and the parallel beams L1 and L2 are deflected. The light enters the cores 17a and 17b (see FIG. 2) of the MCF 17.

  The MCF 17 is a multi-core fiber that connects the multiplexing device 13 and the demultiplexing device 14 that are arranged apart from each other. As shown in FIG. 2, the MCF 17 includes a communication core 17a that propagates communication light necessary for optical communication, and energy transmission cores 17b and 17b that are different from the communication core 17a and perform energy transmission. And a clad 17c covering both the cores 17a and 17b. The communication core 17 a is disposed at the center along the central axis of the MCF 17. The energy transmission cores 17 b and 17 b are arranged on the outer side in the radial direction so as to be located on a concentric circle with the central axis of the MCF 17 as the center, and the energy transmission cores 17 b and 17 b are centered on the central axis of the MCF 17. As shown in FIG.

  For example, the diameter of the cladding of the MCF 17 is about 125 μm, the diameter of the communication core 17 a is about 10 μm, and the diameter of the energy transmission core 17 b is about 25 μm. That is, the diameter of the energy transmission core 17b is formed larger than the diameter of the communication core 17a, and the cross-sectional area of the energy transmission core 17b is more than twice the cross-sectional area of the communication core 17a.

  As described above, the light L1 incident on the communication core 17a and the light L2 incident on the energy transmission core 17b have different wavelengths such as wavelengths λ1 and λ2, respectively. The influence of the light transmitted through the core 17b on the communication light is reduced. In addition, the communication core 17a and the energy transmission core 17b are arranged apart from each other so that the shortest separation distance (distance between the closest positions in each core) is at least about 20 μm. Negative effects are further reduced.

  For example, the numerical aperture (NA) of the communication core 17a of the MCF 17 is about 0.12, and the numerical aperture (NA) of the energy transmission core 17b of the MCF 17 is 0.2. That is, the numerical aperture of the energy transmission core 17b is larger than the numerical aperture of the communication core 17a. Thus, by increasing the numerical aperture of the energy transmission core 17b, it is possible to avoid light leakage that occurs when the MCF 17 is bent. For example, the numerical aperture can be appropriately changed by changing the material of the core.

  As shown in FIG. 4, the demultiplexing device 14 optically couples the MCF 17 to the SCF 19 a connected to the control photoelectric conversion unit 21 and the SCFs 19 b and 19 b connected to the power supply photoelectric conversion unit 22. It is an apparatus of a micro optical system (space separation optical system), and includes a second optical system S2 and a first optical system S1. Although the transmission directions of the first and second optical systems S1 and S2 included in the demultiplexing device 14 are different, their functions are basically the same as those of the first and second optical systems S1 and S2 of the multiplexing device 13. is there.

  The second optical system S2 is located on the MCF 17 side, and is composed of one condenser lens. The condenser lens of the second optical system S <b> 2 is disposed so as to face the MCF 17 on the axis of the emission end of the MCF 17. The condenser lens of the second optical system S2 is arranged at a position away from the exit end of the MCF 17 by the focal length of the condenser lens. Then, the second optical system S2 has its beam interval reduced toward the first optical system S1 and intersects once at the focal point, and then the beam interval is expanded again to the first optical system S1. Incident.

  The first optical system S1 is located on the SCF 19a, 19b side and is composed of one condenser lens. The condensing lens of the first optical system S1 is disposed so as to face each of the SCFs 19a and 19b on the axis of the incident end of the SCFs 19a and 19b. The condensing lens of the first optical system S1 is disposed at a position away from the incident ends of the SCFs 19a and 19b by a predetermined focal length. Then, the first optical system S1 deflects the plurality of beams transmitted through the condenser lens so as to be parallel to the optical axes of the cores of the SCFs 19a and 19b, and the parallel beams are output from the SCFs 19a and 19b. Incident on each core.

  The sensor device 20 includes a control photoelectric conversion unit 21, a power supply photoelectric conversion unit 22, a control unit 23, and a power supply 24. The photoelectric conversion unit 21 is connected to one end of the SCF 19a, receives communication light transmitted through the communication core 17a, and converts the received light into an electrical signal. The photoelectric conversion unit 21 outputs the converted electric signal to the control unit 23. The control unit 23 is a controller for controlling a sensor for measuring a predetermined value (for example, a current value or a voltage value), and the measurement result indicated by the instruction signal by the communication light from the communication core 17a. The signal is transmitted to the multiplexer 13 side through the same path. The photoelectric conversion unit 21 is composed of, for example, a photodiode (PD).

  The photoelectric conversion unit 22 is connected to one end of the SCFs 19b and 19b, receives light for energy transmission transmitted through the energy transmission core 17b, and converts the received power supply light into electric power. The photoelectric conversion unit 22 supplies the converted power to the power source 24. The power source 24 is a power source for driving the control unit 23 and various sensors driven by the control unit 23. In addition, the photoelectric conversion part 22 is comprised from a photodiode (PD), for example like the photoelectric conversion part 21. FIG.

  As described above, in the optical communication system 1 according to the present embodiment, since the MCF 17 includes the respective cores 17a and 17b for optical communication and optical power transmission, both communication and energy transmission can be easily achieved. It is possible to reduce the influence of optical power feeding on optical communication. Further, since the energy transmission core 17b has a large diameter, it is possible to avoid damaging the MCF 17 even when energy having a relatively high capacity is incident on the energy transmission core 17b. Moreover, even if it is damaged, since it is different from the communication core, the influence on communication can be reduced.

  In the MCF 17, the wavelength λ1 of the communication light L1 propagated through the communication core 17a is different from the wavelength λ2 of the energy transmission light L2 transmitted through the energy transmission core 17b. For this reason, mixing of noise into communication can be reduced.

  As described above, according to the MCF 17 and the optical communication system 1 including the MCF 17, it is possible to transmit energy more effectively when performing optical power feeding.

  In the MCF 17, the cross-sectional area of each energy transmission core 17b and the total cross-sectional area of both the cores 17b are more than twice the cross-sectional area of the communication core 17a. For this reason, it is possible to further reduce damage to the connection portion of the MCF 17 by reducing the power density of energy transmission. The cross-sectional area of the energy transmission core 17b may be 10 times or more the cross-sectional area of the communication core 17a.

  In the MCF 17, the energy transmission core 17b is disposed radially outward from the central axis of the optical fiber with respect to the communication core 17a. Thereby, the communication core 17a is arranged on the center side of the optical fiber, and stable information communication can be performed.

  In the MCF 17, the numerical aperture of the energy transmission core 17b is larger than the numerical aperture of the communication core 17a. As described above, by increasing the numerical aperture of the energy transmission core 17b, it is possible to reduce light leakage from the bent portion even when the MCF 17 is bent. Thereby, it is possible to reduce energy loss in the optical power feeding.

  The present invention is not limited to the above embodiment, and various modifications can be applied. For example, in the above embodiment, a spatial separation optical system of a micro optical system is used as the multiplexing device 13 or the demultiplexing device 14, but as shown in FIG. You may use the apparatus (space separation optical system) provided with the mirror 32. FIG. As shown in FIG. 6, the center opening type mirror 32 has an opening 32a at the center thereof, and the other part is a mirror that reflects light at a predetermined angle. In the demultiplexing device 14, the communication light L <b> 1 emitted from the MCF 17 and the light L <b> 2 for power feeding are condensed by the lens 31 on the central aperture mirror 32, and the communication light L <b> 1 passes through the aperture 32 a of the central aperture mirror 32. On the other hand, the power supply light L2 is reflected at the predetermined locations 32b and 32b, so that the communication light L1 and the energy transmission light L2 are spatially separated. Of course, the same configuration as the demultiplexing device 14 of this spatial separation optical system may be applied to the multiplexing device 13.

  As shown in FIG. 7, an apparatus (a wavelength separation optical system) including a lens 41 and a demultiplexing filter 42 may be used as the demultiplexing apparatus 44. In the demultiplexing device 44, the communication light L <b> 1 emitted from the MCF 17 and the light L <b> 2 for power feeding are deflected into parallel light by the lens 41, and the parallel light is incident on the demultiplexing filter 42. Since the communication light L1 and the energy transmission light L2 are different in wavelength from λ1 and λ2, respectively, the communication light L1 and the energy transmission light L2 are wavelength-separated by being incident on the demultiplexing filter 42. Of course, the same configuration as the demultiplexing device 44 of this wavelength separation optical system may be applied to the multiplexing device 13.

  In the above embodiment, the MCF 17 has one communication core 17a and two energy transmission cores 17b. However, the number of each core can be changed as appropriate, for example, one communication core 17b. Four energy transmission cores 17b may be disposed around the core 17a for use.

  DESCRIPTION OF SYMBOLS 1 ... Optical communication system, 13 ... Multiplexing device (spatial separation optical system), 14 ... Demultiplexing device (spatial separation optical system), 17 ... MCF, 17a ... Core for communication, 17b ... Core for energy transmission, 17c ... Cladding , 44 ... demultiplexer (wavelength separation optical system), λ1, λ2 ... wavelength.

Claims (8)

An optical fiber having a plurality of cores,
A communication core for propagating communication light necessary for communication; an energy transmission core that is different from the communication core and performs energy transmission; and a cladding that covers the communication core and the energy transmission core; With
The diameter of the energy transmission core is larger than the diameter of the communication core, and the wavelength of the communication light transmitted through the communication core and the wavelength of the energy transmission light transmitted through the energy transmission core are: An optical fiber characterized by being different.   2. The optical fiber according to claim 1, wherein a cross-sectional area of the energy transmission core is at least twice a cross-sectional area of the communication core.   The optical fiber according to claim 2, wherein a cross-sectional area of the energy transmission core is 10 times or more a cross-sectional area of the communication core. A plurality of the energy transmission cores are provided in the optical fiber,
4. The optical fiber according to claim 2, wherein a cross-sectional area of the energy transmission core is a sum of cross-sectional areas of the plurality of energy transmission cores. 5.   The optical fiber according to any one of claims 1 to 4, wherein the energy transmission core is disposed radially outward from the central axis of the optical fiber with respect to the communication core.   The optical fiber according to any one of claims 1 to 5, wherein the numerical aperture of the energy transmission core is larger than the numerical aperture of the communication core. A communication core for propagating communication light necessary for communication; an energy transmission core that is different from the communication core and performs energy transmission; and a cladding that covers the communication core and the energy transmission core. And the diameter of the energy transmission core is larger than the diameter of the communication core, the wavelength of the communication light propagated in the communication core and the energy transmission light transmitted in the energy transmission core. Optical fibers with different wavelengths,
A spatial separation optical system that spatially separates the communication light and the energy transmission light at at least one of the input and output ends of the optical fiber;
An optical communication system comprising: A communication core for propagating communication light necessary for communication; an energy transmission core that is different from the communication core and performs energy transmission; and a cladding that covers the communication core and the energy transmission core. And the diameter of the energy transmission core is larger than the diameter of the communication core, the wavelength of the communication light propagated in the communication core and the energy transmission light transmitted in the energy transmission core. Optical fibers with different wavelengths,
A wavelength separation optical system that separates the communication light and the energy transmission light by wavelength at at least one of the input and output ends of the optical fiber;
An optical communication system comprising:

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