Abstract: In each of the plurality of optical fibers, a second diameter portion has a diameter larger than that of a first diameter portion. A tapered portion connects the first diameter portion and the second diameter portion by a tapered surface. In a fiber accommodating, a second accommodating portion has an inner diameter larger than that of a first accommodating portion. Each first diameter portion is located in the first accommodating portion. Each second diameter portion is located in the second accommodating portion. The second accommodating portion includes a plurality of regions divided by imaginary planes perpendicular to the first direction. The tapered portions of the optical fibers adjacent to each other among the plurality of optical fibers are located in the different regions among the plurality of regions.

Abstract: An optical connection component 1 includes an optical fiber 10 having a bent portion BA, and a fiber fixing part 20. The optical fiber 10 includes a glass fiber 11 and a resin coating 12. The fiber fixing part 20 includes an optical array member 24 and a protective resin 23. A distal end of the glass fiber 11 and an end surface of the optical array member 24 form a reference surface S. The bent portion BA is formed in a region including the exposed glass fiber 11. A predetermined section in a region C, which continues from the bent portion BA on a side opposite to an end portion of the optical fiber 10 supported by the fiber fixing part 20 with the bent portion BA interposed therebetween, is inclined to approach the reference surface S while going away from the bent portion BA.

Abstract: An optical connection component 1 includes an optical fiber 10 having a bent portion BA, and a fiber fixing part 20. The optical fiber 10 includes a glass fiber 11 and a resin coating 12. The fiber fixing part 20 includes an optical array member 24 and a protective resin 23. A distal end of the glass fiber 11 and an end surface of the optical array member 24 form a reference surface S. The bent portion BA is formed in a region including the exposed glass fiber 11. A predetermined section in a region C, which continues from the bent portion BA on a 10 side opposite to an end portion of the optical fiber 10 supported by the fiber fixing part 20 with the bent portion BA interposed therebetween, is inclined to approach the reference surface S while going away from the bent portion BA.

Abstract: A preform manufacturing method of the present invention has a hole forming step of forming a plurality of holes in a glass body to produce a glass pipe, and a heating integration step of heating the glass pipe with core rods including core portions being inserted in the respective holes, thereby to implement integration of the core rods and the glass pipe. In the hole forming step, a peripheral hole out of the holes to be formed in the glass body is formed at a position determined in consideration of positional variation of the core portion before and after the integration.

Abstract: A multi-core optical fiber ribbon easily optically connected to another optical component is provided. A multi-core optical fiber ribbon 1 includes a plurality of multi-core optical fibers 10 arranged parallel to one another and a common resin 20, with which the plurality of multi-core optical fibers 10 are collectively coated. A core arrangement direction in which plurality of cores in each of the plurality of multi-core optical fibers 10 are arranged is parallel to or perpendicular to the fiber arrangement direction in which the plurality of multi-core optical fibers 10 are arranged at least at both ends of the multi-core optical fiber ribbon 1.

Abstract: A preform manufacturing method of the present invention has a hole forming step of forming a plurality of holes in a glass body to produce a glass pipe, and a heating integration step of heating the glass pipe with core rods including core portions being inserted in the respective holes, thereby to implement integration of the core rods and the glass pipe. In the hole forming step, a peripheral hole out of the holes to be formed in the glass body is formed at a position determined in consideration of positional variation of the core portion before and after the integration.

Abstract: There is provided a multi-core fiber that can reduce both skew and crosstalk between cores. The multi-core fiber includes a plurality of cores extending along a fiber axis, and optical claddings surrounding the plurality of cores. The skew between optical signals propagating through the plurality of cores is 1 ps/m or less, and the propagation constant difference between two adjacent cores of the plurality of cores is more than 0.

Abstract: A multi-core optical fiber ribbon easily optically connected to another optical component is provided. A multi-core optical fiber ribbon 1 includes a plurality of multi-core optical fibers 10 arranged parallel to one another and a common resin 20, with which the plurality of multi-core optical fibers 10 are collectively coated. A core arrangement direction in which plurality of cores in each of the plurality of multi-core optical fibers 10 are arranged is parallel to or perpendicular to the fiber arrangement direction in which the plurality of multi-core optical fibers 10 are arranged at least at both ends of the multi-core optical fiber ribbon 1.

Abstract: A multi-core optical fiber 1A in which a plurality of cores can easily be identified even in the case where they are symmetrically arranged in its section has seven cores 10 to 16, a visual recognition marker 20, and a shared cladding 30 enclosing the seven cores 10 to 16 and the visual recognition marker 20. The cores 10 to 16, the visual recognition marker 20, and the cladding 30 are respectively made of silica glass as their main element. The cores 10 to 16 and the visual recognition marker 20 extend along the fiber-axis direction. The respective refractive index of the cores 10 to 16 is higher than the refractive index of the cladding 30. The refractive index of the visual recognition marker 20 differs from that of the cladding 30. In the cross-section perpendicular to the fiber-axis, the cores 10 to 16 are arranged such that they have 6-fold rotational symmetry and line symmetry. The visual recognition marker 20 is arranged at a position which breaks such symmetry.

Abstract: There is provided a multi-core fiber that can reduce both skew and crosstalk between cores. The multi-core fiber includes a plurality of cores extending along a fiber axis, and optical claddings surrounding the plurality of cores. The skew between optical signals propagating through the plurality of cores is 1 ps/m or less, and the propagation constant difference between two adjacent cores of the plurality of cores is more than 0.

Abstract: All solid photonic bandgap optical fiber comprising a core region and a cladding region is disclosed. The cladding region surrounding the core region includes a background optical material having a first refractive index and elements arranged in a two-dimensional periodic structure. In one embodiment, each of the elements comprises a center part and peripheral part having a higher refractive than the central part. In other embodiments, each element comprises a plurality of rods having a higher refractive index higher than the fist, the rods of each element arranged in a circle or polygon. Light transmission apparatus and methods of using the fiber are also disclosed.

Abstract: A multi-core optical fiber 1A in which a plurality of cores can easily be identified even in the case where they are symmetrically arranged in its section has seven cores 10 to 16, a visual recognition marker 20, and a shared cladding 30 enclosing the seven cores 10 to 16 and the visual recognition marker 20. The cores 10 to 16 and the visual recognition marker 20 extend along the fiber-axis direction. The respective refractive index of the cores 10 to 16 is higher than the refractive index of the cladding 30. The refractive index of the visual recognition marker 20 differs from that of the cladding 30. In the cross-section perpendicular to the fiber-axis, the cores 10 to 16 are arranged such that they have 6-fold rotational symmetry and line symmetry. The visual recognition marker 20 is arranged at a position which breaks such symmetry.

Abstract: An optical fiber has a plurality of holes in a cladding around a core, and has a high failure strength and small transmission loss. The core is made of glass. The cladding surrounds the core, and the holes are formed in the cladding so as to extend along a central axis of the fiber. The holes are formed with constant intervals therebetween along a circle centered on the core, and each hole has a substantially circular cross section. The cladding is sectioned into two claddings. A residual stress in an inner region that is inside a circumcircle of the holes is a compressive stress.

Abstract: Highly accurate measurement of chromatic dispersions of a device under test that is an optical component is enabled with a simple structure comprising: propagating pump light having a wavelength ?pump and probe light having a wavelength ?probe through the device; calculating the generation efficiency of the idler light with respect to the wavelength ?pump by measuring the power of idler light having a wavelength ?idler output from the device according to four-wave mixing generated in the device; seeking the frequency difference or wavelength difference between the pump light and the probe light that makes an extremum of generation efficiency of the idler light; calculating phase mismatch among the pump light wavelength having such frequency difference or wavelength difference, the probe light wavelength, and the idler light wavelength; and on the basis of such calculation results, calculating the chromatic dispersion of the device at the wavelength ?pump.

Abstract: The chromatic dispersion of an optical component is measured with high accuracy using a simple set-up, which includes a pump light source, a probe light source, and a measuring means. Pump light having a wavelength ?pump and probe light having a wavelength ?probe is propagated through an optical component, with the wavelength ?probe being apart from the wavelength ?pump by a given frequency. The generation efficiency of the idler light with respect to the wavelength ?pump is calculated by measuring the power of idler light having a wavelength ?idler output from the optical component, and by seeking the pump light wavelength for making the generation efficiency a local extreme value, the chromatic dispersion of the optical component is calculated from the result of calculation of phase mismatch among the pump light wavelength having such wavelength as sought, the corresponding probe light wavelength, and the corresponding the idler light wavelength.

Abstract: A method of measuring the bending performance of an optical fiber in a simple manner is provided. Power P1 of light emitted from one end of the optical fiber when light is incident onto the other end of the optical fiber is measured under conditions where the optical fiber 1 is wound at a constant pitch by one layer on the circumferential side of a mandrel 2 and the overall circumference of the optical fiber 1 thus wound is covered with an index matching sheet 5. The refractive index of the index matching sheet 5 substantially matches with the refractive index of resin of the outermost layer of the optical fiber 1.

Abstract: An easily manufacturable optical fiber that has desired properties includes a core region made of a glass, a cladding region made of a glass surrounding the core region and having a first viscosity at a drawing temperature, and a jacket region made of a glass surrounding the cladding region and having a second viscosity that is lower than the first viscosity at the drawing temperature. A plurality of holes that are surrounded by the glass of the cladding region and the glass of the jacket region are circumferentially arranged in a cross section that is perpendicular to a fiber axis and extend along the fiber axis, and 50% or more of the glass surrounding each of the plurality of holes is the glass of the cladding region.

Abstract: A multi-core optical fibre 1A in which a plurality of cores can easily be identified even in the case where they are symmetrically arranged in its section has seven cores 10 to 16, a visual recognition marker 20, and a shared cladding 30 enclosing the seven cores 10 to 16 and the visual recognition marker 20. The cores 10 to 16 and the visual recognition marker 20 extend along the fibre-axis direction. The respective refractive index of the cores 10 to 16 is higher than the refractive index of the cladding 30. The refractive index of the visual recognition marker 20 differs from that of the cladding 30. In the cross-section perpendicular to the fibre-axis, the cores 10 to 16 are arranged such that they have 6-fold rotational symmetry and line symmetry. The visual recognition marker 20 is arranged at a position which breaks such symmetry.

Abstract: A photonic bandgap optical fiber and a method of manufacturing said fiber is disclosed. The photonic bandgap fiber comprises a core region surrounded by cladding region. The cladding region includes a background optical material having a first refractive index, and elements of optical material having a second refractive index higher than said first refractive index. The elements are arranges periodically in the background optical material. At the drawing temperature of the fibered, the background optical material has a viscosity lower than the viscosity of the optical material of the elements.