Abstract: Provided is an optical device whose resin member is less likely to reach a high temperature, as compared with that of a conventional optical device. The optical device (1) includes (i) an optical fiber (11) in which a jacket-removed section (I1) is provided and (ii) a resin member (12) in which the jacket-removed section (I1) is embedded. The jacket-removed section (I1) is a section in which a part of a jacket (112) covering an outer surface of a cladding (111b) is removed so that only a part of the outer surface of the cladding (111b) is exposed in a cross section of the optical fiber (11).

Abstract: Provided is an optical device whose resin member is less likely to reach a high temperature, as compared with that of a conventional optical device. The optical device (1) includes (i) an optical fiber (11) in which a jacket-removed section (I1) is provided and (ii) a resin member (12) in which the jacket-removed section (I1) is embedded. The jacket-removed section (I1) is a section in which a part of a jacket (112) covering an outer surface of a cladding (111b) is removed so that only a part of the outer surface of the cladding (111b) is exposed in a cross section of the optical fiber (11).

Abstract: A fiber laser device 1 includes: a pumping light source 10 that emits pumping light; an amplification optical fiber 30 that amplifies and emits signal light by the pumping light; a detector 71 that detects a power of stimulated Raman scattering light generated from the signal light propagated through the amplification optical fiber 30 or the signal light emitted from the amplification optical fiber 30 in preference to a power of the signal light; and a controller 80 that controls a power of the pumping light based on the power of the light detected by the detector 71.

Abstract: An optical branching device comprises a first lens member comprising a transmitting plane surface, a transmitting convex surface having an approximate center of curvature in the transmitting plane surface, and a first optical fiber and a second optical fiber firmly affixed on the transmitting plane surface of the first lens member. The transmitting convex surface has a wavelength-selective mirror surface that transmits light of a first wavelength and reflects light of a second wavelength. The light of the second wavelength, which is one of the wavelengths of light emitted from the first optical fiber and is reflected and converged by the wavelength-selective mirror surface, enters into the second optical fiber.

Abstract: An optical branching device comprises a first lens member comprising a transmitting plane surface, a transmitting convex surface having an approximate center of curvature in the transmitting plane surface, and a first optical fiber and a second optical fiber firmly affixed on the transmitting plane surface of the first lens member. The transmitting convex surface has a wavelength-selective mirror surface that transmits light of a first wavelength and reflects light of a second wavelength. The light of the second wavelength, which is one of the wavelengths of light emitted from the first optical fiber and is reflected and converged by the wavelength-selective mirror surface, enters into the second optical fiber.

Abstract: An optical fiber cable, comprising a cable main unit with an optical fiber covered by a sheath and terminal units mounted on end portions of the cable main unit, wherein each of the terminal units has a transparent cover member with a refractive index approximately equal to the optical fiber, the cover member of at least one of the terminal units and the optical fiber are welded under such condition that the cover member is brought closer to or into contact with the optical fiber, and the cover member and the optical fiber are integrated with each other.

Abstract: An optical fiber cable, comprising a cable main unit with an optical fiber covered by a sheath and terminal units mounted on end portions of the cable main unit, wherein each of the terminal units has a transparent cover member with a refractive index approximately equal to the optical fiber, the cover member of at least one of the terminal units and the optical fiber are welded under such condition that the cover member is brought closer to or into contact with the optical fiber, and the cover member and the optical fiber are integrated with each other.