Abstract: A method for manufacturing an optical fiber preform includes a deposition step and an introduction step. In the deposition step, glass fine particles are generated from a glass raw material gas in a flame obtained by burning a flammable gas supplied to a burner, and the glass fine particles are deposited to produce a hollow porous glass preform. In the introduction step, a first gas is introduced into an inside of a hollow of the porous glass preform, and a second gas is introduced to an outside of the porous glass preform. In the method, at least one of the first gas and the second gas is a gas containing halogen. In the gas introduction step, the gas containing halogen is introduced so that a first partial pressure of the first gas and a second partial pressure of the second gas are different from each other.

Abstract: An optical fiber includes a glass fiber and a coating resin covering an outer periphery of the glass fiber. The glass fiber includes a core and a cladding. An outer diameter of the glass fiber is 99 ?m or larger and 101 ?m or smaller. The coating resin includes a cured material of an ultraviolet curing resin composition. An outer diameter of the coating resin is 160 ?m or larger and 170 ?m or smaller. A mode field diameter for light having a wavelength of 1310 nm is 7.2 ?m or larger and 8.2 ?m or smaller. Bending loss at a wavelength of 1550 nm when wound in a ring shape having a radius of 10 mm is 0.1 dB/turn or less. Bending loss at the wavelength of 1550 nm when wound in the ring shape having the radius of 7.5 mm is 0.5 dB/turn or less.

Abstract: An optical fiber includes a glass fiber and a coating resin covering an outer periphery of the glass fiber. The glass fiber includes a core, an inner cladding, a trench, and an outer cladding. An outer diameter of the glass fiber is 99 ?m or larger and 101 ?m or smaller. An outer diameter of the coating resin is 160 ?m or larger and 170 ?m or smaller. A mode field diameter for light having a wavelength of 1310 nm is 7.2 ?m or larger and 8.2 ?m or smaller. Bending loss at a wavelength of 1550 nm when wound in a ring shape having a radius of 10 mm is 0.1 dB/turn or less. Bending loss at the wavelength of 1550 nm when wound in the ring shape having the radius of 7.5 mm is 0.5 dB/turn or less.

Abstract: An optical fiber includes a glass fiber and a coating resin covering an outer periphery of the glass fiber. The glass fiber includes a core and a cladding. An outer diameter of the glass fiber is 99 ?m or larger and 101 ?m or smaller. The coating resin includes a cured material of an ultraviolet curing resin composition. An outer diameter of the coating resin is 160 ?m or larger and 170 ?m or smaller. A mode field diameter for light having a wavelength of 1310 nm is 7.2 ?m or larger and 8.2 ?m or smaller. Bending loss at a wavelength of 1550 nm when wound in a ring shape having a radius of 10 mm is 0.1 dB/turn or less. Bending loss at the wavelength of 1550 nm when wound in the ring shape having the radius of 7.5 mm is 0.5 dB/turn or less.

Abstract: An optical fiber includes a glass fiber and a coating resin covering an outer periphery of the glass fiber. The glass fiber includes a core, an inner cladding, a trench, and an outer cladding. An outer diameter of the glass fiber is 99 ?m or larger and 101 ?m or smaller. An outer diameter of the coating resin is 160 ?m or larger and 170 ?m or smaller. A mode field diameter for light having a wavelength of 1310 nm is 7.2 ?m or larger and 8.2 ?M or smaller. Bending loss at a wavelength of 1550 nm when wound in a ring shape having a radius of 10 mm is 0.1 dB/turn or less. Bending loss at the wavelength of 1550 nm when wound in the ring shape having the radius of 7.5 mm is 0.5 dB/turn or less.

Abstract: An optical fiber cable includes: optical fiber units obtained by collecting a plurality of optical fiber ribbons in which a plurality of optical fibers are arranged in parallel; and a slot rod including a plurality of slot grooves formed in a spiral shape in order to store the optical fiber units. The optical fiber units are stranded in a longitudinal direction of the optical fiber cable in a state in which the optical fiber ribbons are not twisted, and the optical fiber units are stored in the longitudinal direction of the optical fiber cable in a state of being untwisted stranding in the slot grooves.

Abstract: An embodiment of the present invention relates to an MMF with a structure for reducing length dependence of optical characteristics while maintaining bend-insensitivity. The MMF has a trench portion provided between a core portion and a cladding portion and having a refractive index lower than that of the cladding portion. In a cross section of the MMF, the trench portion in at least a partial section of the MMF has a non-circularly symmetric shape with respect to an intersection between the optical axis and the cross section.

Abstract: An embodiment of the present invention relates to an MMF with a structure for reducing length dependence of optical characteristics while maintaining bend-insensitivity. The MMF has a trench portion provided between a core portion and a cladding portion and having a refractive index lower than that of the cladding portion. In a cross section of the MMF, the trench portion in at least a partial section of the MMF has a non-circularly symmetric shape with respect to an intersection between the optical axis and the cross section.

Abstract: A multi mode optical fiber includes a core having a refractive index distribution of a curved form, a central part in a radial direction of which protrudes, a cladding provided in the periphery of the core and having a constant refractive index lower than a refractive index of the core and a trench layer provided between the core and the cladding and having a constant refractive index lower than that of the cladding. A width dimension of the trench layer in the radial direction is set to 2 ?m or smaller and a ratio of an absolute value of ? trench that is a refractive index difference between the cladding and the trench layer to an absolute value of ? core that is a maximum refractive index difference between the cladding and the core is set to 0.5 or larger.