A plastic scintillating fiber according to an aspect of the present invention includes: an outermost peripheral layer containing a fluorescent substance that emits scintillation light when it is irradiated with at least one of neutron radiation and heavy-particle radiation; a core disposed inside the outermost peripheral layer and containing at least one type of fluorescent substance that absorbs the scintillation light and wavelength-converts the absorbed light into light having a wavelength longer than that of the absorbed light; and a cladding layer covering an outer peripheral surface of the core and having a refractive index lower than that of the core. A wavelength shifting fiber including the core and the cladding layer, and the outermost peripheral layer covering an outer peripheral surface of the wavelength shifting fiber are integrally formed.

An object of the present disclosure is to allow gain compensation with a simple configuration without adding a new device to the outside. The present disclosure discloses a rare earth doped fiber including a core doped with a rare earth and a cladding region around the core, wherein one or more cavities are provided inside the core, and at least one of the cavities are provided along a longitudinal direction of the rare earth doped fiber.

An optical fiber connector includes: amplifying fibers in which an active element activated by excitation light is added to a core of each of the amplifying fibers. The amplifying fibers are connected together such that an absorption amount of excitation light per unit length increases with an increase of a distance from an incident end of the excitation light. A mode field diameter of laser light propagating through the core is same among the amplifying fibers.

An implantable light delivery device comprises: a core portion cladded in a cladding, the core portion comprising upconversion nano-particles (UCNPs) encapsulated in an encapsulation material. The implantable light delivery device may be used in treatments such as photodynamic therapy to provide an emission of light at a wavelength configured by the selection of UCNPs. The encapsulation material may comprise hydrogel and the cladding may comprise fluorinated ethylene propylene.

An anti-resonant hollow core optical fiber preform that includes an outer cladding, a plurality of structural tubes, and a central support tube. The outer cladding has a length, a central longitudinal axis, and a hollow interior. The plurality of structural tubes are disposed within the hollow interior of the outer cladding, the plurality of structural tubes each having a length that extends the length of the outer cladding. And the central support tube is disposed within the hollow interior of the outer cladding such that the plurality of structural tubes are disposed radially outward of the central support tube, the central support tube having a length that extends along the central longitudinal axis of the outer cladding. Furthermore, the length of the central support tube is less than the length of the outer cladding.

An optical fiber includes a glass fiber, and a resin coating layer covering an outer circumference of the glass fiber. In a spectrum acquired by measuring an amount of eccentricity of the glass fiber from a central axis based on an outer circumference of the resin coating layer at a plurality of measurement points set at a predetermined interval in an axial direction of the glass fiber and applying Fourier transform of a waveform representing the amount of eccentricity at each of the plurality of measurement points, a largest value of amplitude of the amount of eccentricity is 6 μm or less.

A detection system for an alignment sensor, and an alignment sensor and lithographic projection apparatus comprising such a detection system is disclosed. The detection system comprises at least one detection circuit; and a plurality of optical fiber cores for transporting a measurement signal to the at least one detection circuit. At least as subset of the plurality of optical fiber cores are selectively switchable between a detection state and a non-detection state, thereby defining a configurable detection spot.

The present disclosure provides coating compositions and cured products formed from the coating compositions. The cured products can be formed at high cure speeds from the coating compositions and feature low Young's modulus, high tear strength, and/or high tensile toughness. The cured products can be used as primary coatings for optical fibers. The primary coatings provide good microbending performance and are resistant to defect formation during fiber coating processing and handling operations. The coating compositions include an oligomer, an alkoxylated monofunctional acrylate monomer, and preferably, an N-vinyl amide compound.

A polymer optical fiber is provided which shows improved hydrolytic stability. This fiber comprises a polymeric optical core and cladding layer, surrounded by a polymeric overcladding layer which comprises a miscible blend of one or more hydrolytically stable amorphous polymers. By varying the ratios of the component polymers in the overcladding blend, the glass transition temperature and the coefficient of thermal expansion of the overcladding layer may be tuned to optimize the attenuation and bandwidth of the plastic optical fiber.

A method for making an optical fiber device may include using a three-dimensional (3D) printer to generate a preform body including an optical material. The preform body may have a 3D pattern of voids therein defining a 3D lattice. The method may further include drawing the preform body to form the optical fiber device.