Polycrystalline silicon fragments obtained by fracturing polycrystalline silicon blocks wherein a content ratio of polycrystalline silicon powder having a particle size of 500 to 1000 m is 0.1 to 40 ppmw.

The invention concerns 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 comprises a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region comprises 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 comprises hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further comprises a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below Th, wherein Th is at least about 50? C., preferably 50? C.<Th<250? C.

Various embodiments of the present disclosure can include a system for filtering of contaminated fluid. The system can include a fiber manufacturing plant. The system can include a filter system which utilizes a fiber filter produced in the fiber manufacturing plant to clean and recycle a contaminated fluid.

Embodiments include an optical fiber cable comprising a length extending between a first end and a second end, a central cooling tube, a plurality of optical fibers disposed radially around the cooling tube, each optical fiber comprising a fiber core and a cladding disposed around the fiber core, an outer protective cover, and an inner thermal filler disposed between the outer protective cover and the central cooling tube and surrounding each of the optical fibers, wherein each of the central cooling tube, the outer protective cover, the inner thermal filler, and the plurality of optical fibers extend the length of the cable. Various systems and methods for removing imperfections from individual optical fibers and for distributing power across long distances using the optical fiber cable are also provided.

An optical fiber production method includes: drawing an optical fiber from an optical fiber preform; and cooling the optical fiber. When in the cooling process, the optical fiber is passed through a plurality of annealing furnaces and Equation (1) is held. A time constant of relaxation of a structure of glass forming a core in the optical fiber is (T.sub.n). A temperature of the optical fiber at a point in time when the optical fiber is delivered into an nth annealing furnace from an upstream side is T.sub.n. A fictive temperature of glass forming the core at the point in time when the optical fiber is delivered is T.sub.fn. A fictive temperature of glass forming the core after a lapse of time t from the point in time when the optical fiber is delivered is T.sub.f.

20 C.<T.sub.fT.sub.n=(T.sub.fnT.sub.n)exp(t/T(T.sub.n))<100 C.(1)

An optical fiber production method includes: drawing an optical fiber from an optical fiber preform; and cooling the optical fiber. When in the cooling process, the optical fiber is passed through a plurality of annealing furnaces and Equation (1) is held. A time constant of relaxation of a structure of glass forming a core in the optical fiber is (T.sub.n). A temperature of the optical fiber at a point in time when the optical fiber is delivered into an nth annealing furnace from an upstream side is T.sub.n. A fictive temperature of glass forming the core at the point in time when the optical fiber is delivered is T.sub.fn. A fictive temperature of glass forming the core after a lapse of time t from the point in time when the optical fiber is delivered is T.sub.f.

20 C.<T.sub.fT.sub.n=(T.sub.fnT.sub.n)exp(t/T(T.sub.n))<100 C.(1)

Provided is a cooling water spray apparatus including a plurality of spinners disposed to be adjacent to one another along a travel path of a target to be cooled, and a plurality of cooling water spray holes provided on each spinner and configured to spray cooling water. The plurality of spinners may be non-overlappingly disposed with respect to one another.

A fibrous insulation product with improved thermal resistance and method of making it are provided. A plurality of base fibers (e.g. glass) are formed into an insulation product, which may be bindered or unbonded. At least one infrared opacifying agent, such as soot, carbon black or graphite, is applied to the fibrous insulation product such that the base fibers are substantially uniformly coated with opacifying agent. The opacifying agent may be applied, for example, from a fluid suspension or by pulling the fiber through a sooty flame. When opacifying agent applied via a suspension and a binder is desired, it is preferable to avoid binder dispersions that can dislocate the opacifying agent. Alternative binder applications may include co-mingling of base fibers with binder fibers, or other physical or mechanical distributions.

A fibrous insulation product with improved thermal resistance and method of making it are provided. A plurality of base fibers (e.g. glass) are formed into an insulation product, which may be bindered or unbonded. At least one infrared opacifying agent, such as soot, carbon black or graphite, is applied to the fibrous insulation product such that the base fibers are substantially uniformly coated with opacifying agent. The opacifying agent may be applied, for example, from a fluid suspension or by pulling the fiber through a sooty flame. When opacifying agent applied via a suspension and a binder is desired, it is preferable to avoid binder dispersions that can dislocate the opacifying agent. Alternative binder applications may include co-mingling of base fibers with binder fibers, or other physical or mechanical distributions.

First, small-diameter portions of a plurality of optical fibers are inserted into a small-diameter capillary. Then, in a state in which the optical fibers are inserted into the small-diameter capillary until end faces of the optical fibers protrude slightly from an end face of the small-diameter capillary, the optical fibers and the small-diameter capillary are fixed together by using an adhesive. Next, a large-diameter capillary is fixed on an outer periphery of the small-diameter capillary. Then, end faces of the large-diameter capillary, the small-diameter capillary, and the optical fibers (the small-diameter portions) are polished collectively to mirror-finish the end faces of the optical fibers. Next, the large-diameter capillary is removed from the small-diameter capillary. In this way, an optical fiber bundle structure can be obtained.