Abstract: An object of the present disclosure is to enable LPG applied over the entire length of an optical fiber without inhibiting an operation of taking out the optical fiber. The present disclosure relates to an optical fiber cable in which at least one or more optical fibers for transmission in at least two or more modes are gathered, the optical fiber cable including: a linear material abutting on at least one of the optical fibers, in which a thickness of the linear material periodically varies in a longitudinal direction of the linear material.

Abstract: The present disclosure relates to an optical transmission system that transmits signal light by using a multi-core optical fiber having two or more cores as transmission paths, the optical transmission system including two or more transmitters that transmit signal light to adjacent cores, in opposite directions, of the cores, and two or more pump light oscillators that inject pump light into the same cores as transmission cores to which the signal light is transmitted of the adjacent cores such that the pump light propagates in the same directions as or directions reverse to the directions of the signal light, and perform distributed Raman amplification of the signal light by using the pump light, in which a signal light gain of the signal light transmitted from the transmitters is set such that a signal intensity ratio to a crosstalk noise intensity leaked from the adjacent transmission cores is high.

Abstract: A resist composition that generates an acid upon exposure and whose solubility with respect to a liquid developer changes by an action of the acid.

Abstract: The present disclosure is a photonic crystal fiber in which a plurality of holes are formed in a cladding, having a uniform light refractive index, capable of propagating three modes of a fundamental mode, a first higher-order mode, and a second higher-order mode, wherein the plurality of holes are disposed in a triangular lattice pattern so as to surround a center of the photonic crystal fiber with no hole disposed at the center of the photonic crystal fiber, and the photonic crystal fiber has a ratio d/A of a diameter d of each of the holes to a pitch A between the holes such that a confinement loss of a third higher-order mode at a minimum wavelength within a used wavelength range is 1.0 dB/m or more and a confinement loss at a maximum wavelength is 0.001 dB/km or less.

Abstract: The present disclosure aims to provide a short optical fiber-type mode converter having small wavelength dependency. The present disclosure is about a mode converter including a cladding having a constant refractive index, a core having a refractive index higher than the refractive index of the cladding in the cladding, and a refractive index modulation part provided to obliquely cross the core and having a different refractive index from a refractive index of surroundings.

Abstract: An object of the present disclosure is to provide an optical side input/output circuit for allowing light for being input into or output from a side surface of an optical fiber with high efficiency. The present disclosure is an optical side input/output circuit including: a tap unit in which a tap waveguide is formed for allowing light for propagation through a core of an optical fiber for being input into or output from a side surface of the optical fiber; and a refractive index matching unit, having a refractive index higher than a refractive index of the tap waveguide, on the side surface of the optical fiber where the light is allowed for being input or output by the tap waveguide.

Abstract: An objective of the present invention is to provide a mode conversion device capable of designing any coupling efficiency and full width at half maximum, and a design method therefor. According to the present invention, a mode conversion device includes a long period grating at a core of an optical fiber through which light is able to propagate in at least two propagation modes. The long period grating satisfies a relationship of Expression C1, where a full width at half maximum FWHM is a wavelength band in which the coupling efficiency is a half of coupling efficiency of mode conversion at a center wavelength, C is coupling efficiency, Lc is a complete coupling length, Lg is a grating length, ? is a grating pitch, and ?? is a propagation constant difference between the two propagation modes at the center wavelength of a mode conversion target. [ Math .

Abstract: A resin composition for forming a phase-separated structure containing a block copolymer having a first block and a second block, in which the first block is formed of a constituent unit represented by Formula (b1), the second block is formed of a constituent unit represented by Formula (b2m) and a random copolymer having a constituent unit represented by Formula (b2g), and a ratio of a volume of the first block is 20% to 80% by volume.

Abstract: Provided is a new phosphor which can be excited by visible light in a wide band to emit a broad fluorescence spectrum, and also to emit near-infrared light with high intensity. Proposed is a phosphor, which is an oxide comprising Ca, Cu, and Si, wherein the containing molar ratios of the elements are 0.15?Ca/Si<0.25 and 0.13?Cu/Si<0.25.

Abstract: A resin composition for forming a phase-separated structure containing a block copolymer having a first block and a second block, in which the first block is formed of a constituent unit represented by Formula (b1), the second block is formed of a constituent unit represented by Formula (b2m) and a random copolymer having a constituent unit represented by Formula (b2g), and a ratio of a volume of the first block is 20% to 80% by volume.

Abstract: An optical amplifier of the present disclosure includes an optical resonator that includes an amplification fiber capable of amplifying signal light having one or more propagation modes and resonates at least one propagation mode of the signal light amplified by the amplification fiber; an excitation light source that outputs excitation light for exciting the amplification fiber; and a multiplexer that multiplexes the signal light and the excitation light, in which the optical resonator includes a gain clamp setting unit which sets gain clamp for at least one propagation mode out of a plurality of propagation modes resonating in the optical resonator.

Abstract: The optical fiber of the present invention includes a core, and a cladding that is provided on an outer periphery of the core and has a refractive index lower than a refractive index of the core region. In the optical fiber of the present invention, a V value representing a normalized frequency of an LP02 mode is greater than or equal to 4.8 and less than or equal to 6.4.

Abstract: The optical fiber according to the present disclosure is an optical fiber having a pure silica core which is a step index core through which an LPm1 mode with an effective area of 250 ?m2 or more is propagated by setting a relative refractive index difference to 0.60% or less, considering an effective cutoff condition, and only 2 or more modes or the LPm1 mode are propagated, with the optical fiber as the transmission line.

Abstract: A differential mode attenuation compensator includes a first multi-mode optical fiber and a third multi-mode optical fiber in which a plurality of propagation modes propagate in a wavelength of a propagating optical signal; and a second multi-mode optical fiber including a core and a clad and arranged with a central axis aligned between the first multi-mode optical fiber and the third multi-mode optical fiber, in which each loss in the plurality of propagation modes is different in the first multi-mode optical fiber and the third multi-mode optical fiber.

Abstract: The optical fiber of the present invention includes a core, and a cladding that is provided on an outer periphery of the core and has a refractive index lower than a refractive index of the core region. In the optical fiber of the present invention, a V value representing a normalized frequency of an LP02 mode is greater than or equal to 4.8 and less than or equal to 6.4.

Abstract: An optical transmission system according to the present disclosure is a mode multiplexed optical transmission system using a multi-mode optical fiber in which a plurality of propagation modes propagate as a transmission line, the optical transmission system including an optical fiber transmission line (83) that includes an optical fiber with two or more propagation modes; and a plurality of mode converters (91) that are configured to generate mode coupling between at least one pair of the propagation modes, in which a variation in an installation interval of the plurality of mode converters (91) is equal to or less than a threshold value determined by the transmission line length (Lt) of the optical fiber transmission line (83).

Abstract: An optical fiber having a graded index (GI)-type core refractive index profile in which a propagation mode can propagate Z (Z is an integer of 2 or more) or more is provided. In the optical fiber, an ?-parameter is a value in which a propagation constant mutual difference is 1000 rad/m or less in a propagation mode group of a mode group M (M is M=2p+l?1 and 3 or more when a propagation mode is denoted by LPlp).

Abstract: Proposed is a phosphor capable of effectively inhibiting the occurrence of adverse influence of a sulfur-based gas while improving water resistance of the phosphor and effectively inhibiting the corrosion of a metallic member. A phosphor is proposed, which includes particles or a layer provided on the surface of a sulfur-containing phosphor, which contains sulfur in a host material, and containing a crystalline metal borate containing an IIA-Group element, boron, and oxygen.

Abstract: Provided is a phosphor, which is excited by a wide band of visible light, capable of emitting near-infrared light of high intensity. The phosphor comprises a crystal phase represented by a formula (1): MCuSi2O6 (where M comprises one or more of Ba, Sr and Ca), and a crystal phase represented by a formula (2): MCuSi4O10 (where M comprises one or more of Ba, Sr and Ca), wherein a ratio ? of a diffraction peak intensity of MCuSi4O10 with respect to a diffraction peak intensity of MCuSi2O6 in an X-ray diffraction (XRD) pattern obtained by powder XRD measurement using CuK? rays is 0<??0.50.

Abstract: The optical fiber according to the present disclosure is an optical fiber having a pure silica core which is a step index core through which an LPm1 mode with an effective area of 250 ?m2 or more is propagated by setting a relative refractive index difference to 0.60% or less, considering an effective cutoff condition, and only 2 or more modes or the LPm1 mode are propagated, with the optical fiber as the transmission line.