An optical fiber comprises a glass fiber comprising a core and a cladding, and a coating resin layer covering the outer periphery of the glass fiber, wherein the average linear expansion coefficient of the coating resin layer at −50° C. or more and 0° C. or less is 3.3×10.sup.−5/° C. or more and less than 9.0×10.sup.−5/° C.

The present disclosure relates to an optical fiber comprising a glass fiber including a core and a clad; a primary resin layer that coats the glass fiber by being in contact with the glass fiber; and a secondary resin layer that coats the primary resin layer, in which the secondary resin layer is formed from a cured product of a resin composition that includes a base resin containing a urethane (meth)acrylate oligomer, a monomer, and a photopolymerization initiator; and inorganic oxide particles, a volume average particle size of the inorganic oxide particles as measured by a small angle X-ray scattering method is 800 nm or less, and a standardized dispersion of the volume average particle size is 60% or less.

An optical fiber according to an embodiment includes a core, a cladding, and a coating layer. At the boundary between the core and the cladding, the local sound velocity decreases in the direction from the core side toward the cladding side. At least in the cladding, the local sound velocity changes continuously in a radial direction. Further, the line width of the Brillouin gain of the light beam guided by the fundamental mode is 60 MHz or more.

A coated optical fiber coupled to a light source for inactivating pathogens on surfaces or in water. The coated optical fiber includes a substantially UV-transparent core, particles optically coupled to the core, and a substantially UV-transparent polymer coating in contact with the particles. Coating the optical fiber includes optically coupling particles to a surface of an optical fiber core to yield a functionalized core, coating the functionalized core with a polymerizable material, and polymerizing the polymerizerable material to yield a substantially UV-transparent polymer coating on the functionalized core.

An optical fiber according to an embodiment includes a core and a cladding. The average value n1_ave of the refractive index of the core, the minimum value nc_min of the refractive index of the cladding, and the refractive index n0 of pure silica glass satisfy relationships of n1_ave>nc_min and nc_min<n0. The cladding contains fluorine. The fluorine concentration in the cladding is adjusted to be minimum in the outermost portion of the cladding including the outer peripheral surface of the cladding.

The present disclosure relates to an optical fiber article and a method for the production of the optical fiber article. The present disclosure in particular relates to the use of the optical fiber article in a fiber bundle as light guide and/or image guide, for example in an endoscope.

A fiber includes a core and cladding, both of which may have temperature dependent indices of refraction. The materials and size of the core and cladding may be selected such that as the temperature of the core and/or cladding is heated above room temperature, the fiber transitions from supporting multimode optical waveguiding to supporting single mode waveguiding.

A method of manufacturing a glass core preform for optical fibres including providing a porous soot core preform having a central longitudinal hole extending axially therethrough and an a/b ratio of from 0.20 to 0.40; simultaneously dehydrating and doping with fluorine the soot core preform at a temperature of from 1000 C. to 1350 C. by exposing it to an atmosphere containing a chlorine-containing gas and a fluorine-containing gas, the content of the fluorine-containing gas in the atmosphere being of from 0.01% to 0.50% by volume, and simultaneously consolidating the soot core preform and closing the central longitudinal hole by exposing the soot core preform to an atmosphere substantially devoid of fluorine and of chlorine at a consolidation temperature of from 1500 C. to 1650 C., while reducing the pressure down the central hole, thereby forming a glass core preform.

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.

Preparation of halogen-doped silica is described. The preparation includes doping silica with high halogen concentration and sintering halogen-doped silica to a closed-pore state. The sintering includes a high pressure sintering treatment and a low pressure sintering treatment. The high pressure sintering treatment is conducted in the presence of a high partial pressure of a gas-phase halogen doping precursor and densifies a silica soot body to a partially consolidated state. The low pressure sintering treatment is conducted in the presence of a low partial pressure of gas-phase halogen doping precursor and transforms a partially consolidated silica body to a closed-pore state. The product halogen-doped silica glass exhibits little foaming when heated to form fibers in a draw process or core canes in a redraw process.