Optical fiber fixing system, optical fiber butting system and optical fiber fusion-splicing system

An optical fiber fixing system includes a clamp base and a clamp member. The clamp base has a V-groove on a top surface thereof. The depth of the V-groove is configured such that a ridgeline of an optical fiber projects beyond the top surface of the base when the optical fiber is mounted therein. The clamp member has a protrusion on a bottom surface thereof. The protrusion depresses, from the upside, the optical fiber mounted in the V-groove of the clamp base. Further, the protrusion is configured to extend substantially perpendicularly to the axial direction of the optical fiber.