Abstract: An object of the present disclosure is to enable an optical signal propagating through a core of an optical fiber to enter and exit without bending the optical fiber. The optical fiber of the present disclosure includes: a core; a cladding layer having a refractive index lower than a refractive index of the core; and a coating layer that coats an outer periphery of the cladding layer, in which the cladding layer includes: a first cladding portion of which main component is the same as that of the core; and a second cladding portion of which main component is different from the main component of the first cladding portion, and is softer than the first cladding portion, and an interface between the first cladding portion and the second cladding portion is in contact with the core.

Abstract: An object of the present disclosure is to provide an optical coupling device capable of controlling a coupling index of optical coupling between two optical fibers for coupling. An optical coupling device of the present disclosure includes two optical fibers for coupling having a core and a clad, and a refractive index variable member to change the refractive index by irradiation with light between the two optical fibers for coupling.

Abstract: An object of the present invention is to provide an optical network system with high electric power efficiency, an operation method thereof, and an optical line terminal device capable of realizing the same. An optical network system (301) according to the present invention is a bus wiring type optical network system and includes an optical line terminal device (11a) which transmits optical signals (Ls), an optical multiplexer/demultiplexer circuit (12) which inputs some of the optical signals (Ls) to an optical bus core wire (50), and a photoelectric conversion unit (13) which converts the other of the optical signals (Ls) into electric power. The optical network system (301) can effectively utilize the electric power by reusing the electric power wasted in a port (Tf) of an optical fiber coupler.

Abstract: An object of the present invention is to provide a terminal determination device and a terminal determination method, which enable identification of a reflection signal from a terminal portion of an optical fiber to be measured even in a case where a reflection signal caused by multiple reflection appears in an OTDR waveform in a mode in which an OTDR and the optical fiber to be measured are connected at a bent portion. The reflection signal caused by multiple reflection inevitably propagates through a distance equal to a distance between true reflection points more than the other reflection point, because of multiple reflection. Therefore, a distance between the reflection signal and another reflection signal is inevitably coincident with a distance between the other reflection signals.

Abstract: An object of the present disclosure is to provide a utility pole rotation apparatus and a position control method that can reduce not only the number of workers for adjusting an orientation of a scaffold bolt (an orientation of a side surface of the utility pole) but also the number of workers for stopping swinging of the utility pole, which cannot be simultaneously reduced in the related art. The utility pole rotation apparatus according to the present disclosure includes a gripping portion that grips a utility pole, and a roller having a cylindrical shape that contacts the utility pole at an inner side of the gripping portion and rotates the utility pole with a longitudinal direction serving as an axis due to rotation of the roller.

Abstract: The present disclosure has an object to provide a technique for enabling a communication state to be confirmed not in a communication building but in a work site, and to provide a technique for enabling correct splicing between optical cables to be confirmed before fusion splicing.

Abstract: An optical multiplexing and demultiplexing method of the present disclosure includes arranging, face to face, a polished surface of a coated optical fiber whose side surface is polished to a core or a vicinity of the core and a polished surface of an optical waveguide whose propagation constant varies in a longitudinal direction and whose side surface is polished to a core or a vicinity of the core, and aligning the polished surface of the coated optical fiber and the polished surface of the optical waveguide so that desired branching ratio is obtained from one end of the coated optical fiber to the end, distal to the former end, of the optical waveguide by relatively moving the polished surface of the coated optical fiber and the polished surface of the optical waveguide.

Abstract: An optical multiplexing and demultiplexing method of the present disclosure includes arranging, face to face, a polished surface of a coated optical fiber whose side surface is polished to a core or a vicinity of the core and a polished surface of a plurality of optical waveguides that are arranged in parallel in a longitudinal plane and that each have different propagation constants and whose side surfaces are polished to cores corresponding one to one therewith or vicinities of the cores; and aligning the polished surface of the coated optical fiber and the polished surface of the plurality of optical waveguides so that desired branching ratio is obtained from one end of the coated optical fiber to the end, distal to the former end, of one optical waveguide of the plurality of optical waveguides by relatively moving the polished surface of the coated optical fiber and the polished surface of the plurality of optical waveguides.

Abstract: The present disclosure intends to provide an optical signal from an ONU according to a desired service usage state without using the ONU and an OLT. A simulated signal light generation apparatus 10 according to the present disclosure is a simulated signal light generation apparatus 10 for simulating an uplink signal light generated in an optical network unit (ONU) in a passive optical network (PON), and the apparatus includes a usage state control unit 11 that sets a service usage state of the ONU, a signal generation unit 12 that generates an uplink signal frame according to the usage state set by the usage state control unit 11, and an electrical/optical conversion unit 13 that converts an electrical signal from the signal generation unit 12 into an optical signal, and the optical signal from the electrical/optical conversion unit 13 is repeatedly transmitted to an optical fiber core 22.

Abstract: The present disclosure has an object to provide a technique for enabling a communication state to be confirmed not in a communication building but in a work site, and to provide a technique for enabling correct splicing between optical cables to be confirmed before fusion splicing.

Abstract: A manufacturing method of an optical splitter of the present disclosure includes: performing first processing that involves mounting a coated optical fiber on a jig configured to store the coated optical fiber, and polishing the coated optical fiber together with the jig until reaching a vicinity of a core of the coated optical fiber or the core of the coated optical fiber; performing second processing that involves applying a refractive index matching material having a refractive index lower than a refractive index of the core of the coated optical fiber onto a polished face of the coated optical fiber on the jig polished in the first processing or onto a polished face of an optical waveguide circuit having been polished in advance until reaching a vicinity of a core or reaching the core, and then bonding the polished faces to each other; and performing third processing that involves positionally aligning the polished faces bonded with each other in the second processing to move the jig or the optical wavegu

Abstract: An object is to provide a determination device that determines a state of a terminal end portion of a coated optical fiber at any location of the coated optical fiber. Reflection of test light varies in a reflection amount at each wavelength depending on a situation of the terminal end portion of the coated optical fiber. In other words, if the magnitude of the reflection amount at each wavelength can be known, the situation of the terminal end portion of the coated optical fiber can be estimated. The determination device according to the present invention is configured to make test light having a plurality of wavelengths incident from the optical fiber side and determine the test light based on a light intensity ratio of each reflected light beams reflected at the terminal end. In addition, reflection of test light varies in return loss at each wavelength depending on a situation of the terminal end portion of the coated optical fiber.

Abstract: It is intended to provide a cable pulling machine that can avoid, even when installed at a high place, a stop of pulling and a cable installation method. A cable pulling machine according to the present invention includes two roller portions c having outer peripheries between which a cable a is to be held and a guide f that introduces the cable a between the roller portions c. The guide f adjusts an angle ? formed between a straight line connecting respective centers o of the roller portions c and the cable a introduced between the roller portions c to a value of not less than 45° and not more than 90°.

Abstract: An object of the present disclosure is to provide a frequency division multiplexing coherent OTDR, a test method, a signal processing apparatus, and a program that can maintain, even in a case where a DFB laser is used, a spatial resolution equivalent to a spatial resolution achieved when a fiber laser or an external resonant laser is used.

Abstract: An optical fiber side input and output device in which light can be input and output from the side of the tube core cable without adjusting a spacing even in a case where the thickness of the protective tube differs, and a method of designing the optical fiber side input and output device is provided. An optical fiber side input and output device has a structure in which an angle of a central angle of an apex portion of a first jig having a convex portion is appropriately set, and a loss insertion is kept equal to or less than a prescribed value by using a relationship between a spacing at the angle and an insertion loss when light is input and output from the side of the tube core cable.

Abstract: The purpose of the present invention is to provide a hazard prediction method that can perform hazard prediction activities so as to prevent accidents, regardless of skills and personalities of workers.

Abstract: An object of the present invention is to provide, in a local-light coupling technique for improving efficiency of work, an optical fiber local-light coupling apparatus configured to hardly affect communication between an OLT and an ONU while causing light to leak from a coated optical fiber in such an amount that makes it possible to confirm a communication state.

Abstract: Provided are a communication monitoring method and a communication monitoring apparatus capable of an operation of identifying a coated optical fiber regardless of a propagation direction of an optical signal even before communication between an OLT and an ONU is opened.

Abstract: There are provided an optical fiber display system and an optical fiber changeover method each enabling an efficient optical fiber changeover work. The optical fiber display system according to the present invention includes a plurality of core wire identification terminals 101.

Abstract: An object of the present invention is to provide a versatile optical fiber lateral output device that can deal with various types of optical fiber core wires. An optical fiber input-output device according to the present invention includes: a first jig 11 including a recess portion 22 and an optical input-output means 51; a second jig 12 including a projection portion 23 and a guide groove 24; and a pressing unit 14 configured to apply a pressing force in a direction in which the recess portion 22 of the first jig 11 and the projection portion 23 of the second jig 12 approach each other so as to bend an optical fiber core wire 100. Letting R1 be a curvature radius of the recess portion 22 of the first jig 11, ?1 be a central angle of the recess portion 22, R2 be a curvature radius of the projection portion 23 of the second jig 12, and ?2 be a central angle of the projection portion 23, R2?R1 and ?2??1 are satisfied.