Abstract:
Various embodiments of optical fiber designs and fabrication processes for ultra small core fibers (USCF) are disclosed. In some embodiments, the USCF includes a core that is at least partially surrounded by a region comprising first features. The USCF further includes a second region at least partially surrounding the first region. The second region includes second features. In an embodiment, the first features are smaller than the second features, and the second features have a filling fraction greater than about 90 percent. The first features and/or the second features may include air holes. Embodiments of the USCF may provide dispersion tailoring. Embodiments of the USCF may be used with nonlinear optical devices configured to provide, for example, a frequency comb or a supercontinuum.
Abstract:
The present invention is generally directed to a method of making a hollow-core photonic band gap preform from a specialty glass by pressing a specialty glass through a die to form a tube wherein the outer transverse shape of the tube is a hexagon, triangle, quadrilateral, or other polygon; stretching the tube to form a micro-tube with approximately the same outer transverse shape as the tube; stacking a plurality of micro-tubes into a bundle minimizing voids between adjacent micro-tubes and forming a central longitudinal void wherein the plurality of micro-tubes within the bundle comprise an inner structured region of the preform and the central void of the bundle comprises a hollow core in the preform; and inserting the bundle into a jacket tube. Also disclosed are the hollow-core photonic band gap preform and fiber formed by this method.
Abstract:
A thermally stable chalcogenide glass, a process for making the same, and an optical fiber drawn therefrom are provided. A chalcogenide glass having the composition Ge(5−y)As(32−x)Se(59+x)Te(4+y) (0≦y≦1 and 0≦x≦2) is substantially free from crystallization when it is heated past the glass transition temperature Tg or drawn into optical fibers. A process for making the thermally stable chalcogenide glass includes purifying the components to remove oxides and scattering centers, batching the components in a preprocessed distillation ampoule, gettering oxygen impurities from the mixture, and heating the components to form a glass melt. An optical fiber formed from the chalcogenide glass is substantially free from crystallization and exhibits low signal loss in the near-infrared region, particularly at wavelengths of about 1.55 μm.
Abstract:
A method is provided for eliminating crystals in non-oxide optical fiber preforms as well as optical fibers drawn therefrom. The optical-fiber-drawing axis of the preform is aligned with the force of gravity. A magnetic field is applied to the preform as it is heated to at least a melting temperature thereof. The magnetic field is applied in a direction that is parallel to the preform's optical-fiber-drawing axis. The preform is then cooled to a temperature that is less than a glass transition temperature of the preform while the preform is maintained in the magnetic field. When the processed preform is to have an optical fiber drawn therefrom, the preform's optical-fiber-drawing axis is again aligned with the force of gravity and a magnetic field is again applied along the axis as the optical fiber is drawn from the preform.
Abstract:
There is provided a feedback-controlled self-heat-monitoring fiber, including an insulator having a fiber length with at least one metal-semiconductor-metal thermal sensing element along the fiber length and disposed at a position in a cross section of the fiber for sensing changes in fiber temperature. An electronic circuit is connected to the thermal sensing element for indicating changes in fiber temperature. A controller is connected for controlling optical transmission through an optical transmission element, that is disposed along the fiber length, in response to indications of changes in fiber temperature.
Abstract:
A thermally stable chalcogenide glass, a process for making the same, and an optical fiber drawn therefrom are provided. A chalcogenide glass having the composition Ge(5−y)As(32−x)Se(59+x)Te(4+y) (0≦y≦1 and 0≦x≦2) is substantially free from crystallization when it is heated past the glass transition temperature Tg or drawn into optical fibers. A process for making the thermally stable chalcogenide glass includes purifying the components to remove oxides and scattering centers, batching the components in a preprocessed distillation ampoule, gettering oxygen impurities from the mixture, and heating the components to form a glass melt. An optical fiber formed from the chalcogenide glass is substantially free from crystallization and exhibits low signal loss in the near-infrared region, particularly at wavelengths of about 1.55 μm.
Abstract:
An optical fiber, which has a zero-material dispersion wavelength equal to or greater than 2 μm, and a high nonlinear susceptibility χ3 equal to or greater than 1×10−12 esu, and uses tellurite glass having sufficient thermal stability for processing into a low loss fiber, employs a PCF structure or HF structure having strong confinement into a core region. This enables light to propagate at a low loss. The size and geometry of air holes formed in the core region, and the spacing between adjacent air holes make it possible to control the zero dispersion wavelength within an optical telecommunication window (1.2-1.7 μm), and to achieve large nonlinearity with a nonlinear coefficient γ equal to or greater than 500 W−1 km−1.
Abstract:
In general, in one aspect, the invention features a method that includes exposing a surface to a first gas composition under conditions sufficient to deposit a layer of a first chalcogenide glass on the surface, and exposing the layer of the first chalcogenide glass to a second gas composition under conditions sufficient to deposit a layer of a second glass on the layer of the first chalcogenide glass, wherein the second glass is different from the first chalcogenide glass.
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:
A system and method for preparing chalcogenide glass are provided that allow for larger quantities of glass to be produced with lower production costs and less risks of environmental hazards. The system includes a reaction container operable to hold chalcogenide glass constituents during a glass formation reaction, a stirring rod operable to mix the contents of the reaction container, a thermocouple operable to measure the temperature inside the reaction container, and a reaction chamber operable to hold the reaction container. The method includes placing chalcogenide glass constituents in a reaction container, heating the chalcogenide glass constituents above the melting point of at least one of the constituents, promoting dissolving or reaction of the other constituents, stirring the reaction melt, maintaining an overpressure of at least one atmosphere over the reaction melt, and cooling the reaction melt to below the chalcogenide glass transition temperature.