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Author

Komo Kunihiro

Bio: Komo Kunihiro is an academic researcher. The author has contributed to research in topics: Optical fiber & Optical fiber cable. The author has an hindex of 5, co-authored 23 publications receiving 54 citations.

Papers
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Patent
28 Jun 2006
TL;DR: In this paper, the authors proposed a multiple optical fiber cable (MOF) consisting of single coated optical fibers, each of which is composed of a photonic crystal fiber with a coating applied on the outer circumference.
Abstract: PROBLEM TO BE SOLVED: To provide a multiple optical fiber cable in which optical fibers are highly densely collected by storing them closely to each other, in which density of coated optical fibers is increased as much as possible inside the optical fiber cable, and in which the cable has a small diameter, light weight and low optical loss. SOLUTION: This is a multiple optical fiber cable comprising single coated optical fibers 11 each of which is composed of a photonic crystal fiber with a coating applied on the outer circumference. A plurality of single coated optical fibers 11 are collected straight or twistedly, with an identification string or tape 12 wound on the outer circumference. Further, as a characteristic of the multiple optical fiber cable, the optical fibers wound with the identification string or tape 12 are gathered straight or twistedly in numbers and covered with a jacket 13 on the outer circumference. COPYRIGHT: (C)2007,JPO&INPIT

8 citations

Patent
16 Jul 2013
TL;DR: In this article, the Brillouin gain spectrum at a point on an optical fiber line can be obtained in a single measurement by counter propagation of a probe light pulse train including X probe light pulses different by frequencies and a pump light pulses, which pair with the probe light beams.
Abstract: PROBLEM TO BE SOLVED: To achieve the reduction of measurement time about an optical fiber strain variation of an optical fiber line in a lengthwise direction of the optical fiber line.SOLUTION: Measurement in a short time can be achieved by allowing a Brillouin gain spectrum at a point on an optical fiber line to be obtained in a single measurement. Concretely, the Brillouin gain spectrum is obtained by counter propagation of a probe light pulse train including X probe light beams different by frequencies and a pump light pulse train including X pump light beams different by frequencies, which pair with the probe light beams. A frequency difference of an i-th probe-pump pair (pair of a probe light beam and a pump light beam) is changed from that of an (i-1)th probe-pump pair by Δf, and the Brillouin gain spectrum is obtained from Brillouin gains of respective probe light beams obtained by this change of frequency differences.

7 citations

Patent
14 Apr 2016
TL;DR: In this article, the authors proposed a method for measuring the temperature and distortion distribution of an optical fiber regardless of a measurement distance, by comparing a plurality of rear Rayleigh scattering light waveforms after phase noise compensation.
Abstract: PROBLEM TO BE SOLVED: To provide a method for highly accurately measuring the temperature and distortion distribution of an optical fiber regardless of a measurement distance.SOLUTION: Rear Rayleigh scattering light measurement with OFDR (Optical Frequency Domain Reflectometry) is executed a plurality of time. Influence of phase noise of a frequency sweep continuous light source 1, occurring in each rear Rayleigh scattering light waveform obtained by each measurement, is compensated by a connected reference method. Then, by comparing a plurality of rear Rayleigh scattering light waveforms after phase noise compensation, temperature and distortion distribution can be measured with high accuracy even in a measurement distance exceeding about 1/2 of a coherence length of the frequency sweep light source.SELECTED DRAWING: Figure 2

7 citations

Patent
05 Jan 2017
TL;DR: In this paper, the authors proposed a mode coupling ratio distribution measuring apparatus that has measuring means aggregated on one side of a mode multiplex optical fiber transmission line multiplexing a plurality of modes, and can perform measurement superior in dynamic range than a conventional method.
Abstract: PROBLEM TO BE SOLVED: To provide a mode coupling ratio distribution measuring apparatus that has measuring means aggregated on one side of a mode multiplex optical fiber transmission line multiplexing a plurality of modes, and can perform measurement superior in dynamic range than a conventional method, and also accurately grasp even a mode coupling ratio at a mode conversion point where different kinds of optical fiber are connected.SOLUTION: A mode coupling ratio distribution measuring apparatus 301 has a frequency difference corresponding to a Brillouin frequency shift of an optical fiber 250 to be measured as a number-mode optical fiber multiplexing a plurality of modes at one end of the optical fiber 250 to be measured, and is configured to make probe light pulses given a predetermined time delay and pump light pulse incident at a predetermined mode excitation ratio, and to receive rear Rayleigh scattered light of probe light pulses output from one end of the optical fiber 250 to be measured and Brillouin-amplified with pump light through mode selection.SELECTED DRAWING: Figure 1

5 citations

Patent
15 Feb 2007
TL;DR: In this article, the authors proposed a shape memory material which is composed of a shape-memory shape with an elastic property in the cable axial direction, and characterized the optical fiber cable in which a single or a plurality of numbers of optical fibers are covered with a jacket sheath integrally with a tension member.
Abstract: PROBLEM TO BE SOLVED: To provide an optical fiber cable whose optical wiring work can be quickly performed to improve installation efficiency and whose wiring for any length can be effectively performed. SOLUTION: The optical fiber cable in which a single or a plurality of numbers of optical fibers 32 is covered with a jacket sheath 31 integrally with a tension member 33 is characterized in that at least either the tension member 33 or the jacket sheath 31 is composed of a shape memory material which has shape-memory shape with an elastic property in the cable axial direction. COPYRIGHT: (C)2007,JPO&INPIT

5 citations


Cited by
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Patent
18 May 2009
TL;DR: In this article, an optical fiber ribbon that includes two-dimensionally disposed resin portions for bonding the adjacent 2-fiber mono-coated optical fibers in plural places, the resin portions being disposed apart from each other in the longitudinal direction of the optical fibre ribbon, is presented.
Abstract: Amono-coated optical fiber that has a bending loss characteristic in which an optical loss increase at a bending radius 13 mm is 0.2 dB/10 turn or less, an optical fiber ribbon that includes two-dimensionally disposed resin portions for bonding the adjacent 2-fiber mono-coated optical fibers in plural places, the resin portions being disposed apart from each other in the longitudinal direction of the optical fiber ribbon and an optical fiber cable that includes a cable core portion that stores twisting of plural units where the mono-coated optical fibers constituting the optical fiber ribbon are collected.

203 citations

Patent
30 May 2008
TL;DR: In this article, an optical fiber cable is configured by having a sheath that houses a core assembly of optical fibers, wherein a prescribed water stop characteristic can be achieved while satisfying a sufficient mechanical characteristic.
Abstract: Provided is an optical fiber cable which is configured by having a sheath that houses a core assembly of optical fibers, wherein a prescribed water stop characteristic can be achieved while satisfying a sufficient mechanical characteristic. The optical fiber cable is provided with: a core assembly (1) comprising a plurality of optical fibers (11) and water stop threads (12); a tape body (2) that covers the core assembly (1); and a cylindrical sheath (5) that covers the core assembly (1) and the tape body (2). The tape body (2) is permeable, so that when water enters inside the tape body (2) the water stop threads (12) dissolve and the dissolved water stop material flows inside the sheath (5).

28 citations

Patent
29 Jun 2007
TL;DR: In this paper, an optical cable is constituted of an optical fiber 30 inserted into a hollow part of a sheath 20 while leaving a space 20a, and a packing member 40 fixing part of the optical fiber to the inner face of the sheath.
Abstract: PROBLEM TO BE SOLVED: To avoid influences on an inner optical fiber even when external stress is added. SOLUTION: An optical cable is constituted of an optical fiber 30 inserted into a hollow part of a sheath 20 while leaving a space 20a, and a packing member 40 fixing part of the optical fiber to the inner face of the sheath. The other part of the optical fiber is open. Even when stress such as bending or expansion and contraction is added to the sheath, the stress does not reach the inner optical fiber. Even if the sheath is slightly expanded by expansion or contraction, the other end of the optical fiber is open and does not expand or contract with the expansion or contract of the sheath. Therefore, influence of stress on the optical fiber can be avoided, and the length of the optical fiber is always kept to a given length. COPYRIGHT: (C)2009,JPO&INPIT

24 citations

Patent
17 Apr 2018
TL;DR: In this article, a distributed optical fiber sensing system for measuring temperature, strain and vibration simultaneously is presented, based on an optical time domain reflectometry (ODTR) multiplexing technology.
Abstract: The invention discloses a distributed optical fiber sensing system for measuring temperature, strain and vibration simultaneously. Based on an Optical Time Domain Reflectometry (ODTR) multiplexing technology, optical time-division multiplexing unequal-width dipulse serves as detection light, coherent detection technologies of Brillouin scattering signals and Rayleigh scattering signals are merged,and a set of distributed optical fiber sensing system which can conduct single-ended measuring on the temperature, strain and vibration is achieved; meanwhile, the measuring range of the vibration frequency can reach the MHz level, and the problems are solved that a traditional ODTR system can only measure the temperature strain or the static strain while cannot timely respond to the dynamic change, or it is hard to measure the temperature strain and the static strain simultaneously, or the measurable range of the vibration frequency is limited by the length of sensing optical fiber. The distributed optical fiber sensing system can conduct single-ended measuring, and is simple in structure, easy to implement, and good in application prospect.

11 citations

Patent
23 Jul 2009
TL;DR: In this paper, the problem of providing an optical fiber cable in which a coated optical fiber is suitably curled to improve work efficiency when a sheath is torn at the terminal of the cable and the optical fiber ribbon is taken out, and to provide a method of manufacturing the same.
Abstract: PROBLEM TO BE SOLVED: To provide an optical fiber cable in which a coated optical fiber is suitably curled to improve work efficiency when a sheath is torn at the terminal of the cable and the coated optical fiber is taken out, and to provide a method of manufacturing the same. SOLUTION: The optical fiber cable 1 uses, as the coated optical fiber, an optical fiber ribbon 21 integrated while either of single coated optical fiber 211 and a wire body 212 is tensed up in the longitudinal direction of the cable, and hence when the sheath 23 is torn to release the tensed state and the optical fiber ribbon 21 is taken out of the cable 1, the optical fiber ribbon 21 is curled and, as a result, a slack of the cable 1 can be easily stored into a miniaturized termination box to improve the work efficiency. Further, the optical fiber ribbon 21 is thus curled, and therefore even when the cable 1 is terminated, the conventional base material or the like for fusion or mechanical splice can be used to provide the optical fiber cable 1 excellent also in cost reduction countermeasure. COPYRIGHT: (C)2009,JPO&INPIT

10 citations