Abstract:
A double crucible fiberizing apparatus and process for producing a continuous glass filament having a core fluoride-containing glass concentrically surrounded by a clad fluoride-containing glass at increased throughput speeds while simultaneously achieving increased length and uniform filament diameter are disclosed.
Abstract:
A method and apparatus is disclosed which ensures highly accurate control of the core-cladding diameter, enabling the fabrication of a preform for the single mode fiber. Moreover, glass refining steps for dehydration, the removal of compound ions, the reduction of the absorption loss by transition metals, etc. and preform manufacturing steps are combined into a series of steps, and the entire manufacturing process can be mechanized and automatically controlled; therefore, the yield rate of product is high and the industrial-scale productivity is also excellent.
Abstract:
The present invention relates to a method of producing a fluoride glass preform and/or fiber having a modified refractive index by heating the fluoride glass preform to a temperature that is above its glass transition temperature, but below its devitrification temperature; inserting a first electrode into the inner core of the preform and surrounding the outer perimeter of the preform with a second electrode of opposite polarity; means for generating an electromotive force; and applying an electromotive force through the first electrode and the second electrode which causes a movement of positive ions toward the electrode of opposite charge while simultaneously causing a movement of negative ions toward its electrode of opposite charge such that the movement of these ions results in a modification of the refractive index of the preform.
Abstract:
Heavy metal fluoride glasses are made by a process that requires high purity fluoride constituent compounds, some of which are further refined by sublimation. Handling occurs in a protective atmosphere such as argon. The charge is placed in a sealed modified optical growth furnace having the ability of atmosphere control, heat control and position control of the charge. The charge is firstly raised to its fusion temperature, then to an admixture temperature, and finally to a higher temperature. The charge is immediately removed from the heating source and quickly cooled through the critical crystallization region. The total heating and cooling time being about one to two hours. The resulting glass ingot is partially annealed. The HMFG of (Zr or Hf)F.sub.4 -BaF.sub.2 -LaF.sub.3 -AlF.sub.2 consistently exhibits low levels of both light scattering and bulk OH contact, along with very reproducible hardness, thermal parameters, and UV and IR edge absorption behavior.
Abstract:
A chalcogenide glass rod and/or a fluoride glass rod are covered with a thermally shrinkable synthetic resin tube, the resulting assembly being heated under vacuum to produce a preform, and a thermally shrinkable synthetic resin tube with a plurality of said preforms formed in a bundle and inserted thereinto is drawn again under heating.
Abstract:
Fluoride glass cladded optical fibers are produced by rotationally casting a fluoride glass cladding tube, introducing core glass melt therein to form a preform, and drawing the preform into a fiber. Disclosed are methods whereby the process may be adopted to the production of multimode, stepped index profile waveguides, single mode waveguides, and waveguides having parabolic index profiles.
Abstract:
An optical fiber with a graded index crystalline core (2,3) is made by filling a tube (1) with a mixture of two salts for which the one with the higher melting point has the lower refractive index. A graded composition results from partition effects when the fused salts are slowly cooled so that solidification proceeds uniformly inwardly from the tube wall. Fiber is pulled conventionally from the reesulting preform, and later is passed through a short hot zone to convert the core into single crystal form.
Abstract:
An apparatus used for the fabrication of fiberoptic waveguides utilizing a novel melting and resolidifying apparatus and method while under microgravity conditions is disclosed. In one embodiment, the optical fiber core has a lower melting point than the cladding and the core is melted and resolidified under microgravity conditions. The molten lower melting point core is thus contained by the higher melting point cladding while under microgravity conditions.
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:
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.