Abstract:
A method for manufacturing an optical fiber, the method including the steps of: providing a substrate tube; depositing high purity silica-based cladding layers on the inside of the tube; depositing a germanium-free core comprising a glass including silica, and oxides of Al, La, Er, and Tm; collapsing the substrate tube to form a preform; and drawing the preform to yield an optical fiber.
Abstract:
It has been discovered that fused silica doped with approximately equimolar amounts of Al and P, has advantageous properties that make such co-doped glass useful in a variety of applications, including optical fiber, especially polarization-maintaining optical fiber, and planar waveguides in optical and optoelectronic devices. In particular, such co-doped fused silica can have a refractive index that is lower than, or at least not significantly greater than, that of pure fused silica, even though both Al and P individually are known up-dopants for silica. The co-doped fused silica also can have a relatively low working temperature, while otherwise maintaining many of the desirable properties of fused silica, e.g., chemical inertness and relatively low coefficient of thermal expansion.
Abstract:
A method of incorporating an additive or dopant oxide into a glass body produced by the oxidation of vaporous source material in a flame. The resultant glassy particles are deposited to form a porous preform having a uniform refractive index. During the consolidation process, the preform is subjected to an atmosphere including a drying agent which penetrates the interstices of the soot preform to simultaneously dry and dope the preform.
Abstract:
A method of making an erbium-doped optical fiber for use in optical amplifiers according to the present invention includes the step of providing a substrate tube. High purity silica-based cladding layers are deposited on the inside of the tube. A core glass that includes silica, Al, a non-fluorescent rare-earth ion, Ge, Er, and Tm is then depositedin the tube. The non-fluorescent rare-earth ion may be La and the core may further include F. The tube is then collapsed to form a preform. Finally, the preform is drawn to yield optical fiber. The core glass may be substantially homogeneous. The core may include at least two regions, wherein one region contains a substantially different Er toTm ratio than the other region. Said regions may be in an annular arrangement. The core of such a waveguide may be made with multiple MCVD passes, multiple sol-gel passes or with multiple soot deposition, solution doping, and consolidation passes.
Abstract:
An optical waveguide including a core having silica, Al, a non-fluorescent rare-earth ion, Ge, Er, and Tm. The non-fluorescent rare-earth ion may be La. Exemplary compositions concentrations are Er is from 15 ppm to 3000 ppm, Al is from 0.5 mol% to 12 mol%, La is less than or equal to 2 mol%, Tm is from 15 ppm to 10,000 ppm; and the Ge is less than or equal to 15 mol%. The core may further include F. An exemplary concentration of F is less than or equal to 6 anion mol%.
Abstract:
The present invention relates to a glass article for use as an optical waveguide fiber (1), the core (4) of which is doped with a chalcogenide element to significantly increase the refractive index of the core (4). The subject of this invention is novel doped silica core composition wherein a portion of the oxygen in the silica is replaced with either sulfur, selenium or tellurium using plasma enhanced chemical vapor deposition (PECVD). These compositions are designed to have higher refractive indices than silica, low coefficient of expansion, high optical transparency and appropriate viscosity and softening points to make them ideal candidates for use as optical waveguide fibers.
Abstract:
A method for controlling the refractive index achieved using a fluorine dopant gas, wherein CF4 is employed as the dopant gas, and the soot preform (12) is doped using the CF4 for a time and temperature sufficient to result in a decrease in fluorine dopant nearest the surface which is in contact with the CF4 gas. Preform (12) is mounted on handle (11) which is fused to handle (14) and the assembly (20) is heated in a furnace muffle (15). The CF4 flows through furnace muffle (15), as indicated by arrows (17), and preferably contains a diluent gas such as helium. An optional centerflow gas (16) may be flowed through the centerline hole (18) in several embodiments, which consists of helium. The end of the porous preform (12) may optionally include a capillary tube (19) to prevent the muffle gases (17) from entering the preform.
Abstract:
A glass powder composite includes a first glass powder, and a second glass powder having a different solubility from that of the first glass powder depending on pH, wherein both the first glass powder and the second glass powder have ion sustained-release properties.
Abstract:
An optical fiber has a core region that is doped with one or more viscosity-reducing dopants in respective amounts that are configured, such that, in a Raman spectrum with a frequency shift of approximately 600 cm−1, the fiber has a nanoscale structure having an integrated D2 line defect intensity of less than 0.025. Alternatively, the core region is doped with one or more viscosity-reducing dopants in respective amounts that are configured such that the fiber has a residual axial compressive stress with a stress magnitude of more than 20 MPa and a stress radial extent between 2 and 7 times the core radius.According to another aspect of the invention a majority of the optical propagation through the fiber is supported by an identified group of fiber regions comprising the core region and one or more adjacent cladding regions. The fiber regions are doped with one or more viscosity-reducing dopants in respective amounts and radial positions that are configured to achieve viscosity matching among the fiber regions in the identified group.