Abstract:
A photonic band gap fiber and method of making thereof is provided. The fiber is made of a non-silica-based glass and has a longitudinal central opening, a microstructured region having a plurality of longitudinal surrounding openings, and a jacket. The air fill fraction of the microstructured region is at least about 40%. The fiber may be made by drawing a preform into a fiber, while applying gas pressure to the microstructured region. The air fill fraction of the microstructured region is changed during the drawing.
Abstract:
An infrared optical fiber containing 30 to 70 % by weight of silver chloride and silver bromide and having a diameter of not more than 0.35 mm has a high mechanical strength. Accordingly, even when this fiber is bent ten thousand times repeatedly at a curvature of 20 mm in radius, which constitutes the condition required of the infrared optical fiber when it is used in a human body, a decrease of the laser beam transmitting capacity thereof, which causes the infrared optical fiber to be burnt, does not occur. This fiber has excellent optical characteristics with respect to an outgoing beam. When a proper load is imposed on this fiber, a non-curved, i.e. linear infrared optical fiber having excellent optical characteristics with respect to an outgoing beam can be obtained. This enables an infrared optical fiber to be manufactured stably in a shorter period of time.
Abstract:
A photonic band gap fiber and method of making thereof is provided. The fiber is made of a non-silica-based glass and has a longitudinal central opening, a microstructured region having a plurality of longitudinal surrounding openings, and a jacket. The air fill fraction of the microstructured region is at least about 40%. The fiber may be made by drawing a preform into a fiber, while applying gas pressure to the microstructured region. The air fill fraction of the microstructured region is changed during the drawing.
Abstract:
To overcome problems of fabricating conventional core-clad optical fibre from non-silica based (compound) glass, it is proposed to fabricate non-silica based (compound) glass optical fibre as holey fibre i.e. one contining Longitudinal holes in the cladding. This removes the conventional problems associated with mismatch of the physical properties of the core and clad compound glasses, since a holey fibre can be made of a single glass composition. With a holey fibre, it is not necessary to have different glasses for the core and cladding, since the necessary refractive index modulation between core and cladding is provided by the microstructure of the clad, i.e. its holes, rather than by a difference in materials properties between the clad and core glasses. Specifically, the conventional thermal mismatch problems between core and clad are circumvented. A variety of fibre types can be fabricated from non-silica based (compounds) glasses, for example: single-mode fibre; photonic band gap fibre; highly non-linear fibre; fibre with photosensitivity written gratings and other refractive index profile structures; and rare-earth doped fibres (e.g. Er, Nd, Pr) to provide gain media for fibre amplifiers and lasers.
Abstract:
The present invention is generally directed to a photonic bad gap fiber and/or fiber preform with a central structured region comprising a first non-silica based glass and a jacket comprising a second non-silica based glass surrounding the central structured region, where the Littleton softening temperature of the second glass is at least one but no more than ten degrees Celsius lower than the Littleton softening temperature of the first glass, or where the base ten logarithm of the glass viscosity in poise of the second glass is at least 0.01 but no more than 2 lower than the base ten logarithm of the glass viscosity in poise of the first glass at a fiber draw temperature. Also disclosed is a method of making a photonic bad gap fiber and/or fiber preform.
Abstract:
A known method for producing synthetic quartz glass comprises: (a) reacting a carbonic silicon compound-containing raw material with oxygen in a reaction zone into SiO2 particles, (b) precipitating the SiO2 particles on a sedimentation area by forming a porous SiO2 soot body containing hydrogen and hydroxyl groups, (c) drying the porous SiO2 soot body, and (d) glazing to the synthetic quartz glass by heating the soot body up to a glazing temperature. In order to facilitate cost-efficient production of quartz glass by means of pyrolyzing or hydrolyzing a carbon-containing silicon compound using a carbon-containing raw material, the invention describes the production of a soot body with a carbon content within the range of 1 ppm by weight to 50 ppm by weight.
Abstract:
The present invention is generally directed to a photonic bad gap fiber and/or fiber preform with a central structured region comprising a first non-silica based glass and a jacket comprising a second non-silica based glass surrounding the central structured region, where the Littleton softening temperature of the second glass is at least one but no more than ten degrees Celsius lower than the Littleton softening temperature of the first glass, or where the base ten logarithm of the glass viscosity in poise of the second glass is at least 0.01 but no more than 2 lower than the base ten logarithm of the glass viscosity in poise of the first glass at a fiber draw temperature. Also disclosed is a method of making a photonic bad gap fiber and/or fiber preform
Abstract:
An infrared optical fiber is provided which includes silver halide polycrystals having a composition ratio of silver chloride and silver bromide in the range of 30 to 70 percent by weight of silver chloride, and having an average grain size of 5 .mu.m or less. There also is provided a method of manufacturing such an infrared optical fiber, in which a silver halide single crystal having a composition ratio of silver chloride and silver bromide in the range of 30 to 70 percent by weight of silver chloride is extruded into an infrared optical fiber, while applying an extruding pressure of 70 kg/mm.sup.2 or more and a tensile load which is greater than the yield strength and smaller than the tensile strength.
Abstract:
Optical fibers formed by rolling crystals of infrared transmissive material, such as potassium chloride, have been made into a smooth optical fiber by rolling between smooth grooved rolls (16) and (20) in a heated, atmosphere controlled environment.The Government of the United States of America has rights in this invention pursuant to Contract Number N00014-79-0-0691 awarded by the Department of Defense.
Abstract:
An optical fiber which is able to transmit high power infrared energy, and is flexible and long in life is described. The fiber consists essentially of a mixed crystal of 40 to 45 wt % of thallium bromide and the balance of thallium iodide, each having a purity not less than 99.9%. The fiber is free of any particles having a size not smaller than 1 .mu.m.