Abstract: In various embodiments, a pancake lens block including a shaped reflective polarizer is described. In an embodiment, the shaped reflective polarizer may include an optical element that may be configured to transmit at least a portion of light from a light source. Further, the shaped reflective polarizer may include a wire-grid polarizer that comprises (i) a bolstering substrate, (ii) a wire-grid substrate coupled to the bolstering substrate, and (iii) wire-grids disposed on the wire-grid substrate. The shaped reflective polarizer may be spaced from the optical element by a distance, which may include a cavity filled with a material (such as air or a nanovoided material).

Abstract: A single-mode optical fiber includes a central core surrounded by an outer cladding. The optical fiber includes at least first and second depressed claddings positioned between the central core and the outer cladding. The central core typically has a radius of between about 3.5 microns and 5.5 microns and a refractive-index difference with the outer cladding of between about ?1×10?3 and 3×10?3. The first depressed cladding typically has an outer radius of between about 9 microns and 15 microns and a refractive-index difference with the outer cladding of between about ?5.5×10?3 and ?2.5×10?3. The second depressed cladding typically has an outer radius of between about 38 microns and 42 microns and a refractive-index difference with the first depressed cladding of between about ?0.5×10?3 and 0.5×10?3.

Abstract: Optical devices and a method for manufacturing these devices. One optical device includes a core region having a first medium of a first refractive index n1, and includes a cladding region exterior to the core region. The cladding region includes a second medium having a second refractive index n2 higher than the first refractive index n1. The cladding region further includes a third medium having a third refractive index n3 lower than the first refractive index n1. The third medium is dispersed in the second medium to form a plurality of microstructures in the cladding region. Another optical device includes a plurality of core regions including at least one core having a doped first medium, and includes a cladding region exterior to the plurality of core regions. The core regions and the cladding region include a phosphate glass.

Abstract: In a known method for drawing a tubular quartz glass strand, SiO2-containing starting material is fed to a melting crucible, softened therein into a viscous quartz glass mass (27), and said mass is pulled vertically downward as a cylindrical quartz glass strand (5; 33) through a die (4; 34) provided in the bottom region of the melting crucible (1), said die having a gap-shaped outlet (25; 36), which is defined by a bottom opening and a die inside part, and thereafter the quartz glass cylinder is cut to length.

Abstract: To improve a known method for making a quartz glass tube as a semifinished product for the manufacture of optical fibers, the tube comprising an inner fluorine-doped quartz glass layer and an outer quartz glass layer, so as to achieve inexpensive manufacture and improved dimensional stability of the quartz glass tube, it is suggested according to the invention that the quartz glass of the inner layer should be produced in a first plasma deposition process with formation of an inner layer having a wall thickness of at least 1.5 mm, with a fluorine content of at least 1.5% by wt. being set in the quartz glass, and that the quartz glass of the outer layer should be produced in a second plasma deposition process and deposited directly or indirectly on the inner layer with formation of a composite tube, and that the composite tube should be elongated into the quartz glass tube.

Abstract: A side-hole optical cane for measuring pressure and/or temperature is disclosed. The side-hole cane has a light guiding core containing a sensor and a cladding containing symmetrical side-holes extending substantially parallel to the core. The side-holes cause an asymmetric stress across the core of the sensor creating a birefringent sensor. The sensor, preferably a Bragg grating, reflects a first and second wavelength each associated with orthogonal polarization vectors, wherein the degree of separation between the two is proportional to the pressure exerted on the core. The side-hole cane structure self-compensates and is insensitive to temperature variations when used as a pressure sensor, because temperature induces an equal shift in both the first and second wavelengths. Furthermore, the magnitude of these shifts can be monitored to deduce temperature, hence providing the side-hole cane additional temperature sensing capability that is unaffected by pressure.

Abstract: A method of manufacturing a microstructured fiber, includes: providing a preform having a plurality of elongate holes; mating at least one, but not all, of the holes with a connector to connect the hole(s) to an external pressure-controller; drawing the preform into the fiber while controlling gas pressure in the hole(s) connected to the pressure-controller.

Abstract: There is provide an optical fiber end processing method, for processing an end portion of an optical fiber having a core and a clad surrounding the core, comprising: fixing two places of the optical fiber; firstly heating a part at a tip end side of the optical fiber between fixed parts fixed at two places, thereby melting the optical fiber at the heated part at the tip end side; secondly heating a part at a base end side of the optical fiber between the fixed parts away from the heated part at the tip end side in a state that the optical fiber is fixed at two places, thereby forming an expanded core region which is formed by expanding a diameter of the core by diffusing the dopant included in the optical fiber; and removing at least the heated part at the tip end side.

Abstract: A method and device for making high precision glass tubes. A glass rod is pushed into a heated chamber and the tube is pulled from the chamber. Preferably, both the push rate and the pull rate are controlled. Fiber optic glass ferrules and other components manufactured by the use of this invention have precision dimensions that fall well within the tight dimensional tolerances required for ferrules and others.

Abstract: A method for making a large surface area silicon filament for production of bulk polysilicon by chemical vapor deposition (CVD) includes melting silicon and growing the filament from the melted silicon by an EFG method using a shaping die. The cross sectional shape of the silicon filament is constant over its axial length to within a tolerance of 10%. In embodiments, a plurality of identical and/or dissimilar filaments are grown simultaneously using a plurality of shaping dies. The filaments can be tubular. Filament cross sections can be annular and/or can include outwardly extending fins, with wall and/or fin thicknesses constant to within 10%. Filaments can be doped with at least one element from groups 3 and 5 of the Periodic Table. The filament can have a length equal to a length of a specified slim rod filament, and a total impedance not greater than the slim rod impedance.

Abstract: A method of manufacturing a cylindrical glass optical waveguide preform having a low water content centerline region, for use in the manufacture of optical waveguide fiber, is disclosed. The centerline region of the glass optical waveguide preform has a water content sufficiently low such that an optical waveguide fiber producible from the glass optical waveguide preform of the present invention exhibits an optical attenuation of less than about 0.35 dB/km, and preferably less than about 0.31 dB/km, at a measured wavelength of 1380 nm. Method of manufacture of a porous core mandrel used in the manufacture of such a glass optical waveguide preform is also disclosed.

Abstract: A method and device for making high precision glass forms (110). A glass rod (1) is pushed into a melting tube (47) and the glass form is pulled from the chamber. Preferably, both the push rate and the pull rate are controlled. Fiber optic glass ferrules and other components manufactured by the use of this invention have precision dimensions that fall well within the tight dimensional tolerances required for ferrules and others.

Abstract: In a known method for producing tubes of quartz glass, a hollow cylinder (2) of quartz glass is continuously supplied to a heating zone (1) and is softened therein in regions, and a tube strand (21) is drawn off at a drawing speed from the softened region with formation of a drawing bulb (26), and the tubes to be produced are cut to length in the form of tube strand pieces by separating the tube strand (21) at a desired separation point (T, Vu, Vo) and an internal pressure differing from the external pressure applied to the outer cladding is maintained in the inner bore (4) of the hollow cylinder (2) in that the inner bore (4) of the tube strand is provided with a flow obstacle.

Abstract: An intermediate preform is formed in a process of manufacturing an optical fibre by forming a sol containing a glass precursor; pouring the sol in a mold containing a set of elongate elements; aging the sol to obtain a gel body; removing the set of elongate elements from the gel body to create a corresponding set of holes in the gel body; and removing the gel body from the mold. The method further provides imparting a motion of the set of elongate elements during aging of the sol to avoid adhesion of the gel to the elongate elements, the motion being preferably a rotation about the respective axes or an alternate translation along the respective axes. An apparatus with means for carrying out the method is also described.

Abstract: The present invention relates to a method for making a glass-glass connection between at least two coaxial, mutually overlapping, glass capillary tubes, wherein one of these two glass tubes is a column for chromatography, for example gas chromatography. Furthermore, the present invention also relates to a method for reversing such a glass-glass connection as well as to a device for making a glass-glass connection between at least two coaxial, mutually overlapping, glass capillary tubes.

Abstract: The production of an optical component from quartz glass, by elongation of a coaxial arrangement of a core rod and a hollow cylinder of a given length, is known. The arrangement is thus introduced into a heating zone with a vertical orientation, such that the lower end begins to partly soften and the component is drawn downwards from the softened part. The hollow cylinder has an inner passage, provided with a restriction in the region of the lower end thereof, on which the core rod is supported. Several methods are disclosed for formation of the restriction in which the inner passage (55) is mechanically machined to a final dimension and, in one version of the method, the restriction in the inner passage (55) is generated by means of softening the lower end face of the hollow cylinder, swaged against a tool and thus folded inwards with formation of a peripheral bead ring.

Abstract: A fabrication method of an optical fiber using as a core material tellurite glass. The method includes a first process of molding a tellurite glass melt into a mold, the mold having a plurality of convex portions defining an inner wall, which portions run parallel to each other in a longitudinal direction in order to make a polygon columnar glass preform, and a second process of inserting the glass preform into a cylindrical jacket tube made of tellurite glass and carrying out fiber-drawing under pressure so as to maintain or enlarge air holes which are gaps generated between the glass preform and the jacket tube.

Abstract: An optical fiber having a longitudinal direction and a cross-section perpendicular thereto, said fiber in a cross-section comprising: (a) a core region (11) having a refractive index profile with a highest refractive index nc, and (b) a cladding region comprising cladding features (10) having a center-to-center spacing, ?, and a diameter, d, of around 0.4? or larger, wherein nc, ? and d are adapted such that the fiber exhibits zero dispersion wavelength of a fundamental mode in the wavelength range from 1530 nm to 1640 nm; a method of producing such a fiber; and use of such an optical fiber in e.g. an optical communication system, in an optical fiber laser, in an optical fiber amplifier, in an optical fiber Raman amplifier, in a dispersion compensator, in a dispersion and/or dispersion slope compensator.

Abstract: A preform for a microstructured fibre or a part for a preform for a microstructured fibre. The preform or part has a length in the longitudinal direction and a cross section perpendicular thereto, and includes a rod arranged at the centre of the preform or part, with one or more tubes being concentric to the rod. The rod is sleeved inside a first of the concentric tubes, and the rod and/or at least one of the concentric tubes has grooves and/or slits extending in the longitudinal direction, with the number of innermost longitudinally extending grooves and/or slits with respect to a centre of the preform or part being at least six.

Abstract: A simple, economic wet chemical procedure is described for making sol-gel fibers. The sol-gel fibers made from this process are transparent to ultraviolet, visible and near infrared light. Light can be guided in these fibers by using an organic polymer as a fiber cladding. Alternatively, air can be used as a low refractive index medium. The sol-gel fibers have a micro pore structure which allows molecules to diffuse into the fiber core from the surrounding environment. Chemical and biochemical reagents can be doped into the fiber core. The sol-gel fiber can be used as a transducer for constructing an optical fiber sensor. The optical fiber sensor having an active sol-gel fiber core is more sensitive than conventional evanescent wave absorption based optical fiber sensors.

Abstract: Stress exerted on an inner or outer circumferential side of a glass tube 6 is controlled when a glass material 3 is heated and softened by a heating element 41 provided around the glass material 3 and a piercing plug 31 is relatively pressed into a softened region of the glass material 3 to thereby form the glass material 3 into the glass tube 6 gradually. For example, the control of the stress can be carried out by controlling an internal or external pressure of the glass tube 6. As a result, the deformation of the glass tube 6 just after piercing is prevented so that the glass tube 6 can be obtained with high quality. It is also possible to solve the problem that cracks may occur easily at the time of reheating because of residual stress distribution after cooling.

Abstract: Disclosed is a method of making a photonic crystal optical fiber preform by stacking and bonding individual glass disks. In one embodiment, each glass disk has a pattern of voids formed therethrough, and the pattern for each disk is the same. In another embodiment, glass blanks are formed without voids and stacked with disks having voids wherein an optical fiber preform is formed having channels closed at both ends by glass having no channels. Also disclosed is an optical fiber having channels closed at both ends by glass without channels.

Abstract: A fluorescent lamp capable of fully securing a portion for containing a mercury amalgam pellet and reliably preventing the mercury amalgam pellet from moving toward the inside a discharge tube, and a method for manufacturing the fluorescent lamp. The fluorescent lamp includes a glass tube having a fluorescent substance layer on the inner surface, a sealed portion formed at an end of the glass tube, a slender glass tube having an inner space that is in communication with the inside of the glass tube and is not in communication with the outside of the glass tube, and a mercury amalgam pellet contained in the slender glass tube. The slender glass tube has a small-diameter part with an inner diameter smaller than the diameter of the mercury amalgam pellet and a large-diameter part with an inner diameter larger than the diameter of the mercury amalgam pellet.

Abstract: A microporous structure can be formed from ductile material such as glass into an axially extended outer wall surrounding a plurality of singular micro-passages surrounded by the outer wall to provide an open area that extends continuously over the length of the outer wall. The diameter of the micro-passages will usually not exceed 25 &mgr;m and are more in range of from 0.5 to 5 &mgr;m. The structure is particularly useful as frits for the containment of packing in capillaries for chromatograph applications and more generally as flow restrictors. Continuous open diameters of the micro-passages have a relatively straight flow path that reduces pressure drop relative to the random arrangement of other frits while still providing the desired containment.

Abstract: A method produces homogenous quartz glass plates without streaks. The method is applied to starting quartz glass body which has an X—X geometrical axis and good refractive index homogeneity in its central area, and a refractive index homogeneity decreasing as the axis lies further from a central area. The body is divided into at least two concave parts by longitudinal cuts parallel to the axis once the central area has been processed out of the body. The parts are placed separately in corresponding molds and heated therein such that they are molded to form quartz glass plates having a desired thickness.

Abstract: A method of manufacturing glass parts for connection of glass fibers is provided, which can improve the accuracy of the cross-sectional size of a through hole in the glass part. A mother glass having a similar cross section to a desired cross section of a glass part having a through hole is prepared, and the prepared mother glass is drawn while it is heated.

Abstract: A method of making a glass article such as an optical waveguide preform is disclosed. The method comprises drawing a rod in at least two steps. In the first step an elongated, consolidated preform having an aperture therethrough is drawn to a reduced diameter preform. The second step involves drawing the reduced diameter preform into a rod, preferably at a lower temperature than the first step. The method substantially reduces the formation of inclusions in the glass article during drawing.

Abstract: The invention comprises devices composed of at least one microscopic hollow tube having a wall of single or multiple layers with a thickness of at st one nanometer and a diameter of at least 5 nanometers. The walls of the tubes can be formed from a wide variety of materials, some of the preferred materials include metals, polymers, carbon, ceramics, glasses. If the space between the tubes is filled, the tubes become channels in a monolithic or composite body. The channels can have a random or ordered orientation. The interior of the tube walls can be coated with a desired material such as a catalyst and also may have depressions or elevations therein that were imparted to the fibers upon which the tubes are formed. The wall layers may be porous for the purpose of removing the fiber therethrough. Microtubes and microtube devices may be interfaced with the macroscopic world in a number of ways.

Abstract: A hollow high temperature ceramic superconducting fiber (10, 100), a process for making the hollow fibers and an apparatus for carrying out the process are provided. The apparatus functions to simultaneously draw a molten superconducting material (16) and a molten glass material (18) into a hollow preform (25) which is heat treated to form a hollow superconducting fiber (10, 100) which is flexible and has a high electrical current carrying capacity. The glass cladding layer (14, 14') surrounds the hollow superconducting core (12).

Abstract: A loose-fill insulation product having irregularly shaped glass fibers is provided. The loose-fill insulation product shows improved recovery, lower thermal conductivity and requires lower product densities than prior art loose-fill insulation at equivalent fiber diameters.

Abstract: A method for fabricating a large-sized primary treated quartz glass tube by perforating a cylindrical quartz glass mother material by a hot carbon drill press-in-process followed by etching and washing. The large-sized primary treated quartz glass tube is converted to a large-sized quartz glass preform by combining it with a core glass rod for an optical fiber. Another embodiment is a method for fabricating a large-sized quartz glass tube by heating, hot drawing or hot drawing under pressure using a tool-free drawing method under control of an inside pressure of the large-sized primary treated quartz glass tube at a temperature ranging from 1600.degree. C. to 3000.degree. C. to satisfy a specific equation.

Abstract: In a method of making a shaped fiber, a stream of fiberizable material is provided with an original shape and a void fraction from 20% to 80%. The void fraction can be provided by forming a hollow stream, a porous stream or a significantly shaped stream. The stream of fiberizable material has a soft portion at which the shape of the stream can be changed. Preferably the stream is provided by discharging molten fiberizable material through a first tube located in an orifice in a wall of a container, and introducing gas through a second tube into the interior of the molten material. The fiber stream is contacted to change the shape of the stream at the soft portion, preferably by applying torsion downstream from the soft portion. Torsion can be applied by contacting the fiber stream with a first surface moving in a direction generally transverse to the longitudinal axis of the stream.

Abstract: A method of making an insulation product of hollow fibers whereby molten insulation material is centrifuged through a plurality of orifices and gas is directed into the molten insulation material through a plurality of gas conduits, wherein each gas conduit directs gas into one of the portions of the molten insulation material being centrifuged through one of the orifices to form a hollow fiber having a hollow bore formed therethrough. The hollow fibers are combined to form the insulation product.

Abstract: In a method for producing hollow mineral fibers such as glass fibers, molten glass is supplied to a rotating glass spinner having a peripheral wall. The spinner rotates so that molten glass is centrifuged through a first tube positioned at least mostly inside the peripheral wall of the spinner in an orifice to form fibers. Gas is introduced into the interior of the molten glass to form hollow glass fibers. A second tube positioned inside the first tube includes an inlet in the wall of the first tube, wherein the orifice and first tube are adapted to allow gas to be introduced through the inlet from outside the peripheral wall. The hollow glass fibers are then collected to form a product such as a mat.

Abstract: The mineral fiber forming apparatus having electrodes for heating heat softenable mineral material to form a molten mineral mass is disclosed. Organically-coated glass fiber scrap and cullet are supplied to the vessel providing the heat softenable mineral material. An impeller turbulently mixes the molten mineral mass dispersing batch into the molten mineral mass and converting water in the molten mineral bath to steam. Molten mineral material formed by the apparatus includes small seeds and gaseous occlusions. The molten mineral material is fed from an outlet port in the vessel to a rotary spinner which forms hollow mineral fibers having gaseous occlusions of between 1% and 10% by volume by centrifuging the molten mineral material through a rotary bushing.