Abstract:
A method for manufacturing hollow core optical fibers is disclosed comprising continuously feeding a glass rod of the desired cladding composition into a high temperature furnace with the rod in line contact with the inner surface of the glass tube. The glass transition temperature of the rod is substantially lower than the glass transition temperature of the glass tube. The glass rod composition is uniformly distributed on the glass tube inner wall as it enters the furnace hot zone. The ratio of the rod diameter to the glass tube inner diameter and the drawing temperature determine the coating thickness of the glass cladding on the inner surface of the glass tube. As the coated tube is passed through the furnace hot zone peak, the optical fiber is drawn. The rod and tube feed rate, the drawing temperature of the rod and glass tube and the drawing rate of the coated glass tube are selected to yield a hollow core optical fiber, with preselected interior and exterior diameters.
Abstract:
The invention relates to lasers and fiber optics. An amplifying optical fiber operating at a wavelength in the range of 1000-1700 nm comprises an oxide glass core to provide amplification and at least one oxide glass cladding. According to the invention the core contains oxides of elements selected from the group consisting of silicon, germanium, phosphorus, bismuth, aluminum, gallium at concentration of bismuth oxide of 10-4-5 mol %, concentration of silicon and germanium oxides, taken together or separately, of 70-99.8999 mol %, concentration of aluminum and gallium oxides, taken together or separately, of 0.1-20 mol %, concentration of phosphorus oxide from 0 to 10 mol %, and provides a maximum optical gain at least 10 times greater than the nonresonant loss factor in the optical fiber. An outside oxide glass cladding comprises fused silica. The optical fiber core has an absorption band in the 1000 nm region, pumping to which region provides an increased efficiency of power conversion of pump light into luminescence light in the 1000-1700 nm range as compared to pumping to another absorption bands in which pumping brings about luminescence in the 1000-1700 nm range. The optical fiber emits luminescence in the range of 1000-1700 nm when excited by light with wavelengths in the range of 750-12000 nm and a half-height width of the luminescence band of more than 120 nm, and luminescence band boundaries defined as points in which the luminescence intensity drops twice relative to the intensity in the luminescence band maximum lie within the 1000-1700 nm spectral range.
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:
Optical fibers with previously unattainable characteristics and the method of producing the same are disclosed and claimed herein. Specifically, the application discloses and claims a method to produce ZBLAN, Indium Fluoride, Germanate and Chalcogenide optical fibers and other similar optical fibers in a microgravity environment. The resulting optical fibers have unique molecular structures not attainable when optical fibers with the identical chemical composition are produced in a standard 1 gravity environment.The method of the invention requires a novel draw tower and modified preform, which are specifically designed to operate in microgravity environments. A lead wire is inserted into the preform that, when wound onto a spool in the draw tower, causes a fiber to form. The pull rate of the lead wire controls the diameter of the fiber.
Abstract:
An amplifying optical fiber includes a core containing oxides of elements selected from the group consisting of silicon, germanium, phosphorus, bismuth, aluminum, gallium with a concentration of bismuth oxide of 10-4-5 mol %, a total concentration of silicon and germanium oxides of 70-99.8999 mol %, a total concentration of aluminum and gallium oxides of 0.1-20 mol % wherein both aluminum and gallium oxide are present and a ratio of aluminum oxide to gallium oxide is at least two, and a concentration of phosphorus oxide from 0 to 10 mol %, and provides a maximum optical gain at least 10 times greater than the nonresonant loss factor in the optical fiber. An outside oxide glass cladding comprises fused silica. The core has an absorption band in the 1000 nm region, pumping to which region provides an increased efficiency of power conversion of pump light into luminescence light in the 1000-1700 nm range.