A method of making a microstructured optical fiber including loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T.sub.anneal; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material.

A method of making a microstructured optical fiber including loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T.sub.anneal; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material.

An illumination device includes: an optical fiber, the optical fiber allowing light emitted from a light source to be introduced at a first end portion thereof and to be guided through the optical fiber while emitting a portion of the light through a side surface of the optical fiber; a light-transmissive tube, the light-transmissive tube covering the side surface of the optical fiber such that a gap is located between the tube and the side surface of the optical fiber; and a light-shielding cap covering a second end portion of the tube at a side opposite the light source such that a space is located between a bottom portion of the cap and the second end portion of the tube. A second end portion of the optical fiber projects past the second end portion of the tube and is located at an inner side of the cap.

This disclosure relates to polarizing optical fibers and polarization maintaining optical fibers, including active and/or passive implementations. An embodiment includes a polarizing (PZ) optical fiber that includes stress applying parts (SAPs) disposed in a first cladding region, the SAPs comprising a material with a thermal expansion coefficient, ?.sub.SAP. A core region is at least partially surrounded by cladding features and the SAPs. The core includes glass with a thermal expansion coefficient, ?.sub.core. The arrangement of the SAPs satisfies: R.sub.sc=d.sub.SAP/D.sub.sc, where D.sub.sc is the SAP center to core center distance, and d.sub.SAP is the average SAP diameter, and d?=|?.sub.SAP??.sub.core|, and where Rsc and d? may be sufficiently large to induce stress birefringence into the core and to provide for polarized output. Active fibers in which a portion of the fiber is doped may be implemented for application in fiber lasers, fiber amplifiers, and/or optical pulse compressors.

Reflectometric vibration measurement system to monitor multiphase flows in production wells or pipelines using multimode fibers comprising: a sensing multimode optical fiber; an optical source with at least one fiber output port, which generates optical pulses which are to be sent to the sensing fiber; an optical receiver with at least one multimode fiber input port; an optical device with at least 3 multimode fiber ports, in which one port is connected to the optical source, one port to the optical receiver, and one port to the sensing multimode fiber; a system for processing the output signals from the optical receiver, further comprising more than one spatial mode filter. A process for reconfiguring an optical reflectometry system which has already been installed in a monitoring structure is also described.

A traceable cable includes at least one data transmission element, a jacket at least partially surrounding the at least one data transmission element, and a tracing optical fiber incorporated with and extending along at least a portion of a length of the cable. The tracing optical fiber includes a core having a first index of refraction and a cladding having a second index of refraction. The traceable cable also includes at least one launch point provided through at least a portion of the jacket for optically accessing the tracing optical fiber. The launch point includes an optical medium accessible from an exterior of the jacket and in contact with the tracing optical fiber, wherein the optical medium is substantially index-matched to the core of the tracing optical fiber. Related systems and methods are also disclosed.

A method of making a microstructured optical fiber comprising loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T.sub.anneal; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material.

An illumination device includes: an optical fiber, the optical fiber allowing light emitted from a light source to be introduced at a first end portion thereof and to be guided through the optical fiber while emitting a portion of the light through a side surface of the optical fiber; a light-transmissive tube, the light-transmissive tube covering the side surface of the optical fiber such that a gap is located between the tube and the side surface of the optical fiber; and a light-shielding cap covering a second end portion of the tube at a side opposite the light source such that a space is located between a bottom portion of the cap and the second end portion of the tube. A second end portion of the optical fiber projects past the second end portion of the tube and is located at an inner side of the cap.

According to embodiments, an optical fiber may include a core portion comprising an outer radius r.sub.C and a maximum relative refractive index .sub.Cmax. A cladding may surround the core portion and include a low-index trench and an outer cladding. The low index trench may surround the core portion and includes an outer radius r.sub.T and relative refractive index .sub.T. The outer cladding may surround and be in direct contact with the low-index trench. The outer cladding may be formed from silica-based glass comprising greater than 1.0 wt. % bromine and has a relative refractive index .sub.OC, wherein .sub.cmas>.sub.OC>.sub.T. The optical fiber may have a cable cutoff of less than or equal to 1530 nm. An attenuation of the optical fiber may be less than or equal to 0.185 dB/km at a wavelength of 1550 nm.

Alighting device includes an optical fiber having a first end portion from which a light emitted by a light source is introduced, and a second end portion, the optical fiber allowing the light to pass therethrough while radiating from a side surface of the optical fiber to an outside; a tube having light-transmissivity and covering the side surface of the optical fiber, such that a gap is located between the side surface of the optical fiber and the tube; a light-shielding cylindrical body covering the second end portion of the optical fiber, such that a space is located between the second end portion of the optical fiber and the cylindrical body, at least a portion of the light-shielding cylindrical body being disposed in the tube; and a light conductive part on a side surface of the cylindrical body, the light conductive part allowing light radiated from the second end portion of the optical fiber to be conducted to a portion of the tube at an outside of the cylindrical body in a diametrical direction of the cylindrical body.