Abstract: Provided is a special optical fiber for measuring a 3D curved shape, and a system for measuring the 3D curved shape by using a special optical fiber. The special optical fiber comprises: an optical fiber core for transmitting an optical signal; an inner cladding covering the optical fiber core; and an outer cladding covering the inner cladding. In particular, the refractive index (n1) of the optical fiber core, the refractive index (n2) of the inner cladding, and the refractive index (n3) of the outer cladding are set in a relationship of n1?n3>n2. The inner cladding covering the optical fiber core has a cut portion in the longitudinal direction. The optical fiber core is exposed through the cut portion. In addition, the cut portion is filled with a material having the same refractive index as the optical fiber core or the outer cladding.

Abstract: An all-fiber isolator as an optical isolator comprises: an optical fiber acting as an optical light guide for propagating incident light; and a Faraday rotator for rotating by 45° a plane of polarization polarized by the polarizer. The all-fiber isolator exhibits a magneto-optic effect enough to be used as an optical isolator at a visible light wavelength by including quantum dots in a core layer and/or an internal cladding layer of the optical fiber.

Abstract: Disclosed is a medical mask apparatus using optical fibers which can selectively project a laser beam to an entire treated portion or a local portion of skin. A medical mask apparatus using optical fibers for projecting a fine laser beam to the skin to activate skin cells and expedite circulation of blood in the skin is provided.

Abstract: An all-fiber isolator as an optical isolator comprises: an optical fiber acting as an optical light guide for propagating incident light; and a Faraday rotator for rotating by 45° a plane of polarization polarized by the polarizer. The all-fiber isolator exhibits a magneto-optic effect enough to be used as an optical isolator at a visible light wavelength by including quantum dots in a core layer and/or an internal cladding layer of the optical fiber.

Abstract: Disclosed is a low bend loss optical fiber including: a core; an inner layer disposed at outside of the core, which has a refractive index lower than a refractive index of the core, the refractive index of the inner layer gradually decreasing as it becomes farther from the core; and a trench layer disposed at outside of the inner layer, which has a lowest refractive index.