Patent ID: 7580606

Claim:
A method of forming an end part of an optical fiber, comprising: a first step of rotating the end part of the optical fiber about an axis, the optical fiber being stored in a fiber guide of a marker groove forming device, that comprises the fiber guide and N first optical fiber pressing springs formed on a substrate, wherein N is greater than or equal to two, and cutting an outer periphery of a cladding of the optical fiber by first edges of the first optical fiber pressing springs, and forming N parallel marker grooves at predetermined intervals on the optical fiber, wherein: the fiber guide is a groove having two side wall surfaces perpendicular to a plane of the substrate and supporting a side of a stored optical fiber by an inner wall surface, the first optical fiber pressing springs are formed on one of the side wall surfaces of the fiber guide, each first optical fiber pressing spring includes a first plate spring formed on said one of the side wall surfaces and a respective first edge formed on the first plate spring on a side of a central direction of the fiber guide, each first plate spring presses its first edge to the side of the optical fiber stored in the fiber guide with a fulcrum on said one of the side wall surfaces, and the first edges are spaced at predetermined distances from each other in an axial direction of the fiber guide; and a second step of forming an end face of the optical fiber by cleaving one of the N parallel marker grooves formed on the optical fiber.