Abstract: A magnetic toner comprising a toner particle, the toner particle comprising a magnetic body, a crystalline resin A, and an amorphous resin B. The crystalline resin A has a monomer unit (a). The amorphous resin B has a monomer unit (b). A content of the crystalline resin A in the toner is 6.2 to 77.0 mass %. The sum of contents of the crystalline resin A and the amorphous resin B in the toner is 30.0 mass % or more. A content of the monomer unit (a) in the crystalline resin A is 50.0 to 100.0 mass %. Using SPA [(J/cm3)0.5] for a SP value of the crystalline resin A and using SPB [(J/cm3)0.5] for a SP value of the amorphous resin B, SPA and SPB satisfy 0.15?SPB?SPA?2.00.

Abstract: An object of the present disclosure is to alleviate deterioration of transmission characteristics of a fiber due to transmission of ultraviolet light, and to eliminate complication of operation due to frequent replacement of an optical fiber in which deterioration has occurred. The present disclosure is an ultraviolet light irradiation system including: an optical transmission unit that propagates ultraviolet light using a plurality of optical transmission lines; an ultraviolet light source unit that inputs ultraviolet light to each of the optical transmission lines with arbitrary power; and an irradiation unit that irradiates a target location with the ultraviolet light propagated through the plurality of optical transmission lines.

Abstract: An object is to provide an optical side input/output circuit that has wavelength selectivity and is easily disposed at multiple points in a transmission path, and an optical connector. An optical side input/output circuit 301 according to the present invention includes: a grating portion 20 in which a fiber Bragg grating 21 that reflects light of a desired wavelength is formed in the core 51 of an optical fiber 50, the light of the desired wavelength being of light propagating in the core 51; and a tap portion 10 that is disposed at a stage before the grating portion 20 in the propagation direction of the light, and is provided with a tap waveguide 53 that outputs the light reflected by the grating portion 20 from a side surface of the optical fiber 50.

Abstract: An object of the present invention is to provide an ultraviolet light irradiation system and an ultraviolet light irradiation method which are not limited in an ultraviolet light irradiation region and can be introduced economically. The present ultraviolet light irradiation system is a system configured to connect a single ultraviolet light source part and an irradiation part installed in the vicinity of an object place to be sterilized or the like by the optical cable formed by bundling a plurality of optical fibers (the single-core or the multi-core) or the multi-core optical fiber. Since the optical fiber is very thin and does not require power supply for transmitting the ultraviolet rays, even in a fine place where a person or a robot cannot enter, the ultraviolet light can be irradiated by laying the optical fiber or the optical cable.

Abstract: An objective is to provide an acoustic mode propagation speed measurement method and an acoustic mode propagation speed measurement device capable of measuring a propagation speed of an acoustic mode without cutting or processing an optical fiber wire. According to the present invention, an acoustic mode propagation speed measurement method includes: acquiring a frequency shift spectrum of Brillouin scattered light generated in an optical fiber; fitting the frequency shift spectrum using a Gauss function; acquiring a spectral full-width at half maximum w from a fitted curve using the Gauss function; and calculating a propagation speed VA of an acoustic mode of the optical fiber by substituting the acquired spectral full-width at half maximum w into a linear function of the spectral full-width at half maximum w and the propagation speed VA of the acoustic mode.

Abstract: The present invention aims to provide an optical side input/output circuit that has wavelength selectivity and is easily disposed at multiple points in a transmission path, and an optical connector. The optical side input/output circuit 301 includes: a tap portion 10 in which a tap waveguide 53 that outputs light of a higher-order mode from a side surface of an optical fiber 50 is formed, the light of the higher-order mode being of light propagating in the core 51 of the optical fiber 50; and a grating portion 20 that is located in a stage before the tap portion 10 in the propagation direction of the light, and has a grating 21 that converts light of a desired wavelength from a basic mode to the higher-order mode, the grating 21 being formed in the core 51 of the optical fiber 50.

Abstract: An oil-in-water emulsified sunblock cosmetic has excellent feeling when used and maintains a high ultraviolet-ray protective effect even upon contact with water or sweat. The oil-in-water emulsified sunblock cosmetic contains an (A) ultraviolet-ray protective agent and a (B) fatty acid forming a solid at room temperature, the cosmetic is characterized in that 51% or less of the fatty acid is neutralized, and the formulation ratio ((A)/(B) of the (A) ultraviolet-ray protective agent to the (B) fatty acid is in the range of at least 0.1 and less than 10.0. The cosmetic exhibits the unprecedented and surprising property of contact with water causing an improvement to the ultraviolet-ray protective ability. It is preferable for the cosmetic to contain an (C) oily component having IOB of 0.5 or higher.

Abstract: The object is providing a water-in-oil emulsion sunscreen cosmetic having a property not present in the prior art, in which UV protection ability improve upon contact with water, sweat and the like in comparison with that directly after application, and also having pleasant texture and easy to wash off. The present invention provides a water-in-oil emulsion sunscreen cosmetic comprising (A) 6 to 40 mass % of a UV protective agent; (B) an organic-modified clay mineral; (C) an oil-phase-thickening agent, other than (B) and (D) a silicone-based surfactant having an HLB of less than 8, wherein the ratio, [total quantity of component (B) and component (C)]/[total quantity of (E) non-volatile liquid oils except silicone oils], is 0.04 or more and less than 0.68.

Abstract: The present invention is to provide a multi-core optical fiber that can expand its transmission wavelength band, and extend its transmission distance by reducing crosstalk, and also provide a method for designing the multi-core optical fiber. A multi-core optical fiber according to the present invention includes: four cores that are arranged in a square lattice pattern in a longitudinal direction; and a cladding region that is formed around the outer peripheral portions of the cores and has a lower refractive index than the cores, the absolute value of the relative refractive index difference between the cores and the cladding region being represented by ?. In the multi-core optical fiber, the diameter of the cladding region is 125 ± 1 µm, the cutoff wavelength is 1.45 µm or shorter, the mode field diameter MFD at a wavelength of 1.55 µm is 9.5 to 10.0 µm, the bending loss at a wavelength of 1.625 µm and with a bending radius of 30 mm is 0.

Abstract: It is an object of the present disclosure to reduce the risk of information exploitation by a malicious third party while allowing communication data to be demodulated in real time.

Abstract: Provided are an LPFG and an optical transmission system in which a mode conversion amount does not depend on a polarization state and an electric field distribution. The LPFG according to the present invention includes cavity rows (25-1 and 25-2) of cavities 15 periodically arranged in a core region 11 of the few-mode fiber 10 at a position away from a central axis z of the core region 11 in parallel with the central axis z. Each of the cavity rows (25-1 and 25-2) is located at a different position in a longitudinal direction of the few-mode fiber 10 (where the position in a z direction is different), and the cavity rows (25-1 and 25-2) are located at positions shifted by 90° on a cross section of the core region 11 with the center of the cross section of the core region 11 (the intersection of an x-axis and a y-axis) as an origin.

Abstract: An object of the present invention is to provide a light irradiation system capable of securing economic efficiency, flexibility, reliability, and safety, and further capable of reducing a transmission loss between a center side and a remote side. The present light irradiation system can secure economic efficiency by sharing a single light source installed on the center side with a plurality of irradiation places. The present light irradiation system can irradiate a place to be sterilized with ultraviolet light output by moving the optical fiber tip end on the remote side in a pinpoint manner, and can also secure flexibility. In addition, the present light irradiation system can secure reliability and safety by performing output control of the light source on the center side.

Abstract: An object of the present invention is to provide a simple method capable of reducing MDL after construction of a transmission path. An optical connector 301 is an optical connector including a multimode optical fiber 11, in which a core 20 of the multimode optical fiber 11 includes a plurality of cavities 25 along a central axis. The optical connector 301 further includes a ferrule 12 surrounding the multimode optical fiber 11 and a connector plug 13 serving as a connection with another optical connector. The shape of the optical connector 13 is a shape of a generally used SC connector, FC connector, MT connector, or the like.

Abstract: In order to solve the above problems, an object of the present invention is to provide an ultraviolet light irradiation system and an ultraviolet light irradiation method with a few transmission losses in an optical fiber. The ultraviolet light irradiation system 301 includes: a light source unit 11 for injecting transmission infrared light into an optical fiber 50, a wavelength conversion unit 12 for converting the transmission infrared light propagated through the optical fiber 50 into ultraviolet light, and an irradiation unit 13 for irradiating the ultraviolet light on a desired place. The light source unit 11 has a polarization scrambler 11b, and infrared light output from one infrared light source 11a is made to be transmission infrared light by the polarization scrambler 11b.

Abstract: An object of the present invention is to provide an ultraviolet light irradiation system and a decontamination method that are economical and easy to operate, and that can perform decontamination without any input from a user. In the present invention, an optical fiber or an optical waveguide that radiates ultraviolet light in a lateral direction, the optical fiber or the optical waveguide is built in a sheet shape, and irradiates a surface with the ultraviolet light. Specifically, a material in which a material having a high scattering coefficient is added to the optical fiber is used, a grating is formed in the optical fiber, the optical fiber is given a minute bending with a minute ruggedness, and an arbitrary bending is given on the optical fiber, or the like, thereby achieving side radiation. By such a feature, it has the effect that ultraviolet light decontamination can be performed at all times or at necessary timing for an object touched by an unspecified number of people.

Abstract: A multi-core optical fiber includes: four cores arranged in a lattice shape along a longitudinal direction, each of the four cores having a step-index type refractive index distribution with a radius a; and a cladding region having a lower refractive index than that of each core and a diameter of 125±1 ?m and provided on an outer peripheral portion of each core, where an absolute value of a relative refractive index difference between each core and the cladding region is ?. The four cores are arranged so that a relationship between a minimum distance from the center of each core to an outer periphery of the cladding region, a minimum value ? of spacing between the cores, and the MFD satisfies a formula, and the radius a of each core and the relative refractive index difference ? between the core and the cladding region are set.

Abstract: The present disclosure relates to a multi-core optical fiber including: M (where M is a positive integer of 1 or larger) group(s) each consisting of N (where N is a positive integer of 2 or larger) core regions linearly arranged in a cross section; a cladding region that surrounds the plurality of core regions and has a refractive index lower than any of the plurality of core regions; and a coating region that surrounds the cladding region, wherein the plurality of core regions are arranged in line symmetry with respect to both imaginary lines orthogonal to each other at a center of the cladding region, a diameter of the cladding region is 180 ?m or less, and a diameter of the coating region is 235 ?m or more and 265 ?m or less.

Abstract: A communication apparatus includes a first communication unit that communicates with a terminal apparatus using a first communication method, a second communication unit that communicates with a server apparatus using a second communication method different from the first communication method, a reception unit that controls receiving update information from the server apparatus in a case where the communication apparatus can communicate with the server apparatus via the second communication unit, an update unit that performs an update process for updating the communication apparatus using the update information, and a progress management unit that controls transmitting a progress status of a process regarding the update information to the terminal apparatus.

Abstract: An object of the present invention is to provide an ultraviolet light irradiation system and a decontamination method that can perform decontamination economically without any input from a user. The ultraviolet light irradiation system forms a linear or planar ultraviolet light irradiation space by spatially bundling a plurality of ultraviolet light beams with high energy density or moving the ultraviolet light with high energy density at high speed. The ultraviolet light irradiation system can decontaminate a human body and clothing simply by passing through the space. Further, since the ultraviolet light irradiation system performs decontamination in the space, bacteria and viruses emitted from a carrier are not passed through the space.

Abstract: An objective of the present invention is to provide an optical communication system and an optical communication method that can reduce even a delay generated in processing of obtaining a transfer function for correcting distortion in digital coherent transmission. In the optical communication system according to the present invention, pilot data for estimating a transfer function for a transmission channel is transmitted through a transmission channel with a short transmission delay time, a transfer function of the transmission channel is estimated before receiving transmission data, and the transfer function is applied to other transmission channels.