Abstract: In an optical device manufacturing method according to the present invention, a metal film is formed on a side surface of a bare fiber, a film is formed on an end face of the bare fiber, and, thereafter, the bare fiber is inserted into a ferrule until the end face of the bare fiber on which the film was formed is protruded from an end face of the ferrule, and then, the bare fiber is secured to the ferrule. In an optical device according to the present invention, a bare fiber having a side surface on which a metal film was formed is inserted into and secured to a ferrule, and an end face of the bare fiber is protruded from an end face of the ferrule, and a distance L between the end faces satisfies a relationship L<4×d (outer diameter of the bare fiber), and a film is formed on the end face of the bare fiber.

Abstract: An apparatus for the production of a porous optical fiber preform preventing cracks in the preform and stabilizing quality over the longitudinal direction. The apparatus includes a reaction portion, a feed port for introducing a stream of gas, and a main exhaust port. A rotating mechanism is provided for mounting, rotating, and pulling up a seed rod for forming the porous optical fiber preform. A first burner emits a flame carrying fine particles of glass forming the core portion, and a second burner emits a flame carrying fine particles of glass forming the cladding portion. A portion adjusts the flow of the stream from the feed port to the main exhaust port so that the flames carrying the glass particles are not disturbed by the stream and so that the stream does not directly contact a fine glass particle deposit formed at a bottom end of the seed rod.

Abstract: A sheathed optical fiber cutting method and apparatus for cutting the sheathed optical fiber. In one embodiment, the sheathed optical fiber is rotated around its center axis against a cutting blade. An incision is made in an area of the sheathed optical fiber that is under tension from being bent. The incision makes a cut that is flat and perpendicular to the axis of the optical fiber. In one embodiment, the blade for making the incision is mounted in a vibration generator.

Abstract: An optical fiber preform suspending and supporting apparatus able to prevent deformation of a pin placed in a high temperature environment and able to support a porous optical fiber preform without adversely influencing supports of the pin and without causing inclination relative to the vertical line of a main shaft, wherein a movable connector is fitted into an enlarged-diameter portion of the lower end of a main shaft, this enlarged-diameter portion is connected with the movable connector by a pin so that the movable connector is able to swing around the pin, a holding portion including a supporting portion is formed integrally at the bottom of the movable connector to hold an enlarged-diameter portion of the upper end of a starting preform, and the diameter of the pin is in the range of 20% to 50% of the outside diameter of the enlarged-diameter portion of the lower end of the main shaft, and an optical fiber processing apparatus including the same.

Abstract: A sheathed optical fiber cutting method and cutting apparatus for cutting the sheathed optical fiber, under such a condition that the sheathed optical fiber (12) is relatively rotated around its center axis (Ax) against a cutting blade (18) and bent, by making an incision in an area having a bent curvature larger than that of the center of the bent optical fiber along the center axis (Ax), from the tension-applied surface (12A) to which a tension is applied due to fiber bending toward the fiber center.

Abstract: An optical fiber preform suspending and supporting apparatus able to prevent deformation of a pin placed in a high temperature environment and able to support a porous optical fiber preform without adversely influencing supports of the pin and without causing inclination relative to the vertical line of a main shaft, wherein a movable connector is fitted into an enlarged-diameter portion of the lower end of a main shaft, this enlarged-diameter portion is connected with the movable connector by a pin so that the movable connector is able to swing around the pin, a holding portion including a supporting portion is formed integrally at the bottom of the movable connector to hold an enlarged-diameter portion of the upper end of a starting preform, and the diameter of the pin is in the range of 20% to 50% of the outside diameter of the enlarged-diameter portion of the lower end of the main shaft, and an optical fiber processing apparatus including the same.

Abstract: A hooded glass particulate synthesizing torch, provided with at least a glass particulate synthesizing torch body having a feedstock gas injection passage formed at the center of its front end, a combustible gas injection passage formed concentrically at the outer circumference of the feedstock gas injection passage, and a plurality of small diameter combustion aid gas injection passages formed in the combustible gas injection passage along the outer circumference of the feedstock gas injection passage and a hood projecting out at the outer circumference of the front end of the torch body, the torch hood satisfying 0.5≦D/L≦2.0, where, L is the focal distance, that is, a distance from a point P, to which the small diameter combustion aid gas injection passages are directed and on an extension of the center line of the torch body in front of the torch body, to the front end of the torch body, and D is the hood length, that is, the distance from the front end of the hood to the front end of the torch body.

Abstract: In an optical device manufacturing method according to the present invention, a metal film is formed on a side surface of a bare fiber, a film is formed on an end face of the bare fiber, and, thereafter, the bare fiber is inserted into a ferrule until the end face of the bare fiber on which the film was formed is protruded from an end face of the ferrule, and then, the bare fiber is secured to the ferrule. In an optical device according to the present invention, a bare fiber having a side surface on which a metal film was formed is inserted into and secured to a ferrule, and an end face of the bare fiber is protruded from an end face of the ferrule, and a distance L between the end faces satisfies a relationship L<4×d (outer diameter of the bare fiber), and a film is formed on the end face of the bare fiber.

Abstract: Disclosed is a process of producing an optical fiber preform having a step of charging a feedstock gas in an oxygen-hydrogen burner via an electrode and hydrolyzing the same in an oxygen-hydrogen flame to produce particulates containing charged glass particulates and a step of blowing the charged particulates onto a target comprised of a seed rod or a soot body formed on the seed rod so as to cause them to deposit on the target and build up as a soot body. Preferably, the process includes the further step of reducing the magnitude of the charge of the particulates in the burner along with an increase of the diameter of the target which is formed. More preferably, the process also includes the further step of making the position facing the burner across the target an opposite polarity from the charging polarity of the particulates ejected from the burner so as to electrically attract the particulates ejected from the burner.

Abstract: An optical fiber soot synthesis apparatus which synthesizes around a fiber starting member forming a core of an optical fiber an optical fiber soot forming a cladding and which accurately calculates in real time the mass of the optical fiber soot when deposited so as to control the synthesis of the optical fiber soot. The optical fiber soot synthesis apparatus measures the weight of the rotating fiber starting member and optical fiber soot by a pair of soot weight detection sensors arranged at a fiber starting member support and rotational drive mechanisms divided so as to prevent the weight of the rotational drive mechanisms from having much of an effect. The computation and control apparatus performs operational processing from the measured weights and calculates the mass of only the optical fiber soot synthesized on the fiber starting member in real time. The computation and calculation apparatus refers to the calculated mass to control the synthesis of the optical fiber soot.