Abstract: Described herein are systems, methods, and articles of manufacture for a coated fiber modified by actinic radiation to increase back-scattering, which experiences very little back-scattering decay at a temperature and time of exposure that is sufficient to noticeably degrade the coating and/or noticeably degrade the optical fiber due to outgassing of hydrogen from the coating. In one embodiment, an optical fiber comprises a fiber length, a coating having a treated coating weight, wherein the treated coating weight is at least 25% less of an original coating weight prior to an annealing treatment, and an optical back-scatter along the fiber length greater than a Rayleigh back-scattering over the fiber length, wherein the optical back-scatter does not decrease along the fiber length by more than 3 dB after exposure to annealing treatment.

Abstract: Described herein are systems, methods, and articles of manufacture for a spatially nonuniform scattering profile along its length, whose backscattering signal can be used for sensing even after fiber attenuation increases due to the conditions in the sensing environment. In one embodiment, the fiber has been pre-exposed to the conditions that produce attenuation, and the spatially nonuniform profile compensates for this. Subsequent exposure then results in very little or at least acceptable levels of additional attenuation. An exemplary fiber comprises a fiber length and an optical back scatter along the fiber length greater than a Rayleigh back scattering over the fiber length, wherein the optical back scatter does not decrease along the fiber length by more than 3 dB after exposure to a hydrogen-rich first environment having a given pressure and temperature.

Abstract: Disclosed herein is a composition for coating an optical fiber comprising a free radically curable acrylate and/or a methacrylate functionalized oligomer having a density of less than 1.0 g/cm3; where the acrylate and/or the methacrylate functionalized oligomer has a functionality of 1 or more; a photoinitiator; and optionally a free radically curable acrylate and/or methacrylate diluent monomer that has a density of less than 1.0 g/cm3; where the coating composition is disposed and cured on an optical fiber; where the density of the cured coating is less than 1.0 g/cm3; and where the average functionality of the composition is greater than one.

Abstract: Embodiments are directed to a method and device for coupling an optical fiber sensing element to an apparatus under test. A channel is affixed to the apparatus under test. The channel is partially filled with a coupling material. The fiber optic sensing element is placed on the coupling material. Coupling material is placed in the channel to uniformly surround the fiber optic sensing element and tightly couple the fiber optic sensing element to the apparatus under test.

Abstract: Embodiments are directed to a method and device for coupling an optical fiber sensing element to an apparatus under test. A channel is affixed to the apparatus under test. The channel is partially filled with a coupling material. The fiber optic sensing element is placed on the coupling material. Coupling material is placed in the channel to uniformly surround the fiber optic sensing element and tightly couple the fiber optic sensing element to the apparatus under test.

Abstract: Disclosed herein is a composition for coating an optical fiber comprising a free radically curable acrylate and/or a methacrylate functionalized oligomer having a density of less than 1.0 g/cm3; where the acrylate and/or the methacrylate functionalized oligomer has a functionality of 1 or more; a photoinitiator, and optionally a free radically curable acrylate and/or methacrylate diluent monomer that has a density of less than 1.0 g/cm3; where the coating composition is disposed and cured on an optical fiber, where the density of the cured coating is less than 1.0 g/cm3; and where the average functionality of the composition is greater than one.

Abstract: Disclosed herein is a composition comprising 65 to 95 weight percent of a fluorinated monofunctional monomer; 5 to 35 weight percent of a fluorinated multifunctional monomer; and 0.5 to 3 weight percent of a silane coupling agent; where all weight percents are based on the total weight of the composition; where the fluorinated monofunctional monomer and the fluorinated multifunctional monomer are devoid of any trifunctional fluorocarbon moieties when they have 6 or more fluorocarbon repeat units; where the fluorocarbon repeat units are CF2 or CF moieties; and where a crosslinked composition has a shore D hardness of 56 to 85 and has a refractive index (RI) that meets the limitation of the equation RI?1.368+10.8/X, where X denotes wavelength in nanometers.

Abstract: Disclosed herein is a composition comprising 65 to 95 weight percent of a fluorinated monofunctional monomer; 5 to 35 weight percent of a fluorinated multifunctional monomer; and 0.5 to 3 weight percent of a silane coupling agent; where all weight percents are based on the total weight of the composition; where the fluorinated monofunctional monomer and the fluorinated multifunctional monomer are devoid of any trifunctional fluorocarbon moieties when they have 6 or more fluorocarbon repeat units; where the fluorocarbon repeat units are CF2 or CF moieties; and where a crosslinked composition has a shore D hardness of 56 to 85 and has a refractive index (RI) that meets the limitation of the equation RI?1.368+10.8/X, where X denotes wavelength in nanometers.