Abstract: The present invention is a flexible printed circuit board provided with an insulating substrate and a wiring circuit provided on at least one main surface side of the insulating substrate, wherein the wiring circuit has a laminate having a first metal layer that contains first metallic crystal grains and a second metal layer that is adjacent to the first metal layer and contains second metallic crystal grains, with the first metal layer and the second metal layer being laminated along a direction perpendicular to the main surface of the insulating substrate, and the average grain size of the first metallic crystal grains is smaller than the average grain size of the second metallic crystal grains.

Abstract: An electronic component mounting board, including: a substrate base made of a flat-plate-like elastic body, the substrate base having a plurality of through-holes in a manner spaced a predetermined distance apart from each other; conductive members, each of which has a main unit portion filled in the through-hole, the main unit portion having a first protrusion portion and a second protrusion portion respectively on a first end and a second end thereof, with the first protrusion portion arranged so as to protrude from a first surface of the substrate base and the second protrusion portion arranged so as to protrude from a second surface of the substrate base; a flexible substrate that is arranged on the first surface of the substrate base and that has first opening portions for penetration of the first protrusion portions; and a plurality of oval electrodes arranged on the substrate, each of which has a second opening portion for penetration of the first protrusion portion, in which the electrodes are arrange

Abstract: An electronic component mounting board, including: a substrate base made of a flat-plate-like elastic body, the substrate base having a plurality of through-holes in a manner spaced a predetermined distance apart from each other; conductive members, each of which has a main unit portion filled in the through-hole, the main unit portion having a first protrusion portion and a second protrusion portion respectively on a first end and a second end thereof, with the first protrusion portion arranged so as to protrude from a first surface of the substrate base and the second protrusion portion arranged so as to protrude from a second surface of the substrate base; a flexible substrate that is arranged on the first surface of the substrate base and that has first opening portions for penetration of the first protrusion portions; and a plurality of oval electrodes arranged on the substrate, each of which has a second opening portion for penetration of the first protrusion portion, in which the electrodes are arrange

Abstract: An optical fiber coupler is comprised of a fusion-elongated portion 15 in which an optical fiber 11 which is designed and fabricated for use at a wavelength in the vicinity of 1.55 ?m and an optical fiber 12 which is designed and fabricated for use at a wavelength in the vicinity of 0.98 ?m are fused and elongated. The propagation constant difference between optical fibers 11 and 12 is 10?4 rad/?m or smaller.

Abstract: An object of the invention is to improve polarization dependence of insertion loss (PDL) in an ultraviolet light induced optical fiber grating. In the invention, in a method of manufacturing an optical fiber grating with a plurality of grating sections arranged intermittently at a predetermined period along the longitudinal direction, by irradiating, from the side of an optical fiber having locations made of a material wherein the refractive index rises when irradiated by light of a specific wavelength, light of this specific wavelength along the length direction of the optical fiber at a predetermined period, causing the refractive index of the irradiated sections to rise, high refractive index sections are formed by irradiating light evenly onto the optical fiber around the circumferential direction thereof.

Abstract: The invention provides a method and apparatus that precisely and efficiently improves the optical properties of an optical fiber grating. Preferably hydrogen loading processing, grating formation processing that forms a grating part by irradiation with ultraviolet light at a predetermined period, and preferably dehydrogenation, adjusting the optical properties by a suitable combination of uniform ultraviolet irradiation processing that irradiates the grating part as a whole with ultraviolet light and heat trimming processing, and finally heat aging is carried out.

Abstract: The invention provides a method and apparatus that precisely and efficiently improves the optical properties of an optical fiber grating. Preferably hydrogen loading processing, grating formation processing that forms a grating part by irradiation with ultraviolet light at a predetermined period, and preferably dehydrogenation, adjusting the optical properties by a suitable combination of uniform ultraviolet irradiation processing that irradiates the grating part as a whole with ultraviolet light and heat trimming processing, and finally heat aging is carried out.

Abstract: An optical fiber coupler is comprised of a fusion-elongated portion 15 in which an optical fiber 11 which is designed and fabricated for use at a wavelength in the vicinity of 1.55 &mgr;m and an optical fiber 12 which is designed and fabricated for use at a wavelength in the vicinity of 0.98 &mgr;m are fused and elongated. The propagation constant difference between optical fibers 11 and 12 is 10−4 rad/&mgr;m or smaller.

Abstract: An object of the invention is to improve polarization dependence of insertion loss (PDL) in an ultraviolet light induced optical fiber grating. In the invention, in a method of manufacturing an optical fiber grating with a plurality of grating sections arranged intermittently at a predetermined period along the longitudinal direction, by irradiating, from the side of an optical fiber having locations made of a material wherein the refractive index rises when irradiated by light of a specific wavelength, light of this specific wavelength along the length direction of the optical fiber at a predetermined period, causing the refractive index of the irradiated sections to rise, high refractive index sections are formed by irradiating light evenly onto the optical fiber around the circumferential direction thereof.

Abstract: The invention provides a method and apparatus that precisely and efficiently improves the optical properties of an optical fiber grating. Preferably hydrogen loading processing, grating formation processing that forms a grating part by irradiation with ultraviolet light at a predetermined period, and preferably dehydrogenation, adjusting the optical properties by a suitable combination of uniform ultraviolet irradiation processing that irradiates the grating part as a whole with ultraviolet light and heat trimming processing, and finally heat aging is carried out.