Provided are an optical fiber and a manufacturing method of the optical fiber that can reduce transmission loss even when drawing is performed at a high tension and a high rate. An optical fiber has a core to which chlorine is added and a clad to which fluorine is added, chlorine of 9000 to 13000 ppm is added to the core, a relative refractive index difference 1 of the core to a pure silica glass is 0.09 to 0.13%, a relative refractive index difference 2 of the clad to a pure silica glass is 0.36 to 0.17%, a difference (12) between the relative refractive index difference 1 of the core and the relative refractive index difference 2 of the clad is larger than or equal to 0.30%, a mode field diameter at wavelength 1.31 m is 8.8 to 9.6 m, and a stress difference occurring at an interface between the core and the clad is lower than or equal to 60 MPa.

A system and method for nitridizing a glass article includes supplying a source of a nitridizing gas including gaseous NH.sub.3 to a glass article supported within a furnace assembly and heating the glass article. In some embodiments, the system includes a handle assembly configured to support the glass article within the furnace assembly and a gas supply conduit carried by the handle and configured to supply the nitridizing gas to the glass article. In some embodiments, a method of nitridizing a glass article includes supplying the nitridizing gas such that a residence time of the nitridizing gas at temperatures greater than 500 C. corresponds to a predetermined time period. In some embodiments, a method of nitridizing a glass article includes supplying the nitridizing gas such that the glass articles is exposed to the nitridizing gas within a contact time t.sub.c.

A system and method for nitridizing a glass article includes supplying a source of a nitridizing gas including gaseous NH.sub.3 to a glass article supported within a furnace assembly and heating the glass article. In some embodiments, the system includes a handle assembly configured to support the glass article within the furnace assembly and a gas supply conduit carried by the handle and configured to supply the nitridizing gas to the glass article. In some embodiments, a method of nitridizing a glass article includes supplying the nitridizing gas such that a residence time of the nitridizing gas at temperatures greater than 500 C. corresponds to a predetermined time period. In some embodiments, a method of nitridizing a glass article includes supplying the nitridizing gas such that the glass articles is exposed to the nitridizing gas within a contact time t.sub.c.

A Photonic Crystal Fiber (PCF) a method of its production and a supercontinuum light source comprising such PCF. The PCF has a longitudinal axis and includes a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region includes a plurality of microstructures in the form of inclusions extending along the longitudinal axis of the PCF in at least a microstructured length section. In at least a degradation resistant length section of the microstructured length section the PCF includes hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further includes a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below T.sub.h, wherein T.sub.h is at least about 50? C., preferably 50? C.<T.sub.h<250? C.

A Photonic Crystal Fiber (PCF) a method of its production and a supercontinuum light source comprising such PCF. The PCF has a longitudinal axis and includes a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region includes a plurality of microstructures in the form of inclusions extending along the longitudinal axis of the PCF in at least a microstructured length section. In at least a degradation resistant length section of the microstructured length section the PCF includes hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further includes a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below T.sub.h, wherein T.sub.h is at least about 50? C., preferably 50? C.<T.sub.h<250? C.

A Photonic Crystal Fiber (PCF) a method of its production and a supercontinuum light source comprising such PCF. The PCF has a longitudinal axis and includes a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region includes a plurality of microstructures in the form of inclusions extending along the longitudinal axis of the PCF in at least a microstructured length section. In at least a degradation resistant length section of the microstructured length section the PCF includes hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further includes a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below T.sub.h, wherein T.sub.h is at least about 50? C., preferably 50? C.<T.sub.h<250? C.

A Photonic Crystal Fiber (PCF) a method of its production and a supercontinuum light source comprising such PCF. The PCF has a longitudinal axis and includes a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region includes a plurality of microstructures in the form of inclusions extending along the longitudinal axis of the PCF in at least a microstructured length section. In at least a degradation resistant length section of the microstructured length section the PCF includes hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further includes a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below T.sub.h, wherein T.sub.h is at least about 50? C., preferably 50? C.<T.sub.h<250? C.

Fibers for fiber-reinforced resin of the present invention are fibers for fiber-reinforced resin to which a sizing agent is adhered. The fibers are at least one selected from carbon fibers and glass fibers, and an ester bond (COO) generated by denaturation of the sizing agent is present on surfaces of the fibers. A method for producing the same according to the present invention includes: subjecting fibers to which a sizing agent is adhered to at least one treatment selected from the group consisting of ozone oxidation, ultraviolet irradiation at a wavelength of 400 nm or less, and a plasma treatment. The fibers are at least one selected from carbon fibers and glass fibers. Thus, it is possible to provide carbon fibers having enhanced wettability to a matrix resin and thereby allowing the matrix resin to be impregnated between the fibers easily.

Fibers for fiber-reinforced resin of the present invention are fibers for fiber-reinforced resin to which a sizing agent is adhered. The fibers are at least one selected from carbon fibers and glass fibers, and an ester bond (COO) generated by denaturation of the sizing agent is present on surfaces of the fibers. A method for producing the same according to the present invention includes: subjecting fibers to which a sizing agent is adhered to at least one treatment selected from the group consisting of ozone oxidation, ultraviolet irradiation at a wavelength of 400 nm or less, and a plasma treatment. The fibers are at least one selected from carbon fibers and glass fibers. Thus, it is possible to provide carbon fibers having enhanced wettability to a matrix resin and thereby allowing the matrix resin to be impregnated between the fibers easily.

A method for manufacturing an optical fiber, the method includes: exposing a bare fiber formed of glass and having a temperature of 500? C. to 1,500? C. to a gas in which a moisture content is controlled to 2 to 20 g/m.sup.3; applying an uncured resin to an outer periphery of the bare fiber; and curing the resin to form a coating layer.