Abstract:
Methods for forming optical fiber preforms are disclosed. According to one embodiment, a method for forming an optical fiber preform includes forming a preform core portion from silica-based glass soot. The silica-based glass soot may include at least one dopant species for altering an index of refraction of the preform core portion. A selective diffusion layer of silica-based glass soot may be formed around the preform core portion to form a soot preform. The selective diffusion layer may have an as-formed density greater than the density of the preform core portion. A diffusing species may be diffused through the selective diffusion layer into the preform core portion. The soot preform may be sintered such that the selective diffusion layer has a barrier density which is greater than the as-formed density and the selective diffusion layer prevents diffusion of the at least one dopant species through the selective diffusion layer.
Abstract:
Manufacturing an optical fiber by using an outside vapor deposition technique for making a substrate, applying one or more layers to the substrate using a radial pressing technique to form a soot blank, sintering the soot blank in the presence of a gaseous refractive index-modifying dopant, and drawing the sintered soot blank, provides a more efficient and cost effective process for generating complex refractive index profiles.
Abstract:
The invention relates to a silica glass compound having improved physical and chemical properties. In one embodiment, the present invention relates to a silica glass having a desirable brittleness in combination with a desirable density while still yielding a glass composition having a desired hardness and desired strength relative to other glasses. In another embodiment, the present invention relates to a silica glass composition that contains at least about 85 mole percent silicon dioxide and up to about 15 mole percent of one or more dopants selected from F, B, N, Al, Ge, one or more alkali metals (e.g., Li, Na, K, etc.), one or more alkaline earth metals (e.g., Mg, Ca, Sr, Ba, etc.), one or more transition metals (e.g., Ti, Zn, Y, Zr, Hf, etc.), one or more lanthanides (e.g., Ce, etc.), or combinations of any two or more thereof.
Abstract:
A method is provided for forming an optical fiber amplifier. The method comprises providing a composite preform having a gain material core that includes one or more acoustic velocity varying dopants to provide a longitudinally varying acoustic velocity profile along the gain material core to suppress Stimulated Brillouin Scattering (SBS) effects by raising the SBS threshold and drawing the composite preform to form the optical fiber amplifier.
Abstract:
An optical fiber including: (i) a silica based, Yb doped core having a first index of refraction n1, said core comprising more than 1 wt % of Yb, said core having less than 5 dB/km loss at a wavelength situated between 1150 nm and 1350 nm and less than 20 dB/km loss at the wavelength of 1380 nm and slope efficiency of over 0.8; and (ii) at least one silica based cladding surrounding the core and having a second index of refraction n2, such that n1>n2.
Abstract:
What is disclosed includes OD-doped synthetic silica glass capable of being used in optical elements for use in lithography below about 300 nm. OD-doped synthetic silica glass was found to have significantly lower polarization-induced birefringence value than non-OD-doped silica glass with comparable concentration of OH. Also disclosed are processes for making OD-doped synthetic silica glasses, optical member comprising such glasses, and lithographic systems comprising such optical member. The glass is particularly suitable for immersion lithographic systems due to the exceptionally low polarization-induced birefringence values at about 193 nm.
Abstract:
This invention is directed to the production of essentially defect-free high purity fused silica glass articles, the method comprising the following steps: (a) forming a green body from silica particulates or a porous body of amorphous silica; (b) sintering said body in a chamber by raising the temperature of the chamber to above 1720.degree. C., while purging the chamber with helium or applying a vacuum to the chamber; and (c) consolidating the sintered body in a chamber by raising the temperature within the chamber to at least 1750.degree. C., introducing an inert gas into the chamber at a pressure less than about 6.9 MPa (1000 psig), and cooling the chamber while maintaining the pressurized atmosphere to a temperature at least below the annealing point of the glass. In the most preferred practice, a green body of silica particulates will be prepared via a sol-gel process.
Abstract:
According to the present invention, a preform (7) for an optical fiber is made from a tube having a substrate layer (16) of fluorine-doped silica and a support layer (18) of non-doped silica. A cladding layer (8) of fluorine-doped silica and a core layer (10) of non-doped silica are formed on the inside surface of the tube by chemical vapor phase deposition. The optical fiber is subsequently obtained by collapsing the tube and drawing it. The invention is applicable to fabricating optical fibers.
Abstract:
A method is disclosed for making a step-index optical fiber having a steep refractive index gradient between core and cladding. Core glass particles comprising a base glass and a refractive index-increasing dopant are deposited on a mandrel. The mandrel is removed and the resultant soot preform is consolidated to form a core preform having a dopant-poor surface region. The core glass preform is stretched and the hole therein is closed to form a core bait rod. Cladding glass soot is deposited on the core bait rod at a density which is at least 0.5 g/cc. This is accomplished by directing the flame from an auxiliary burner onto the core bait rod immediately prior to the deposition of cladding soot thereon. The resultant preform is consolidated and drawn into an optical fiber. In another embodiment, the etched core preform is overclad with a layer of cladding glass, and the composite preform is stretched prior to applying a second overclad layer.
Abstract:
A method for producing a glass preform for an optical fiber by means at least two burners, comprising jetting a glass raw material containing SiCl.sub.4 from the first center burner and a hydrogen-containing silicon compound with larger reaction heat than SiCl.sub.4 from at least one second burner, flame hydrolyzing the glas raw material to synthesizing fine glass particles, depositing the fine glass particles on a starting member to form a porous soot preform and heating and sintering the soot preform to obtain a transparent glass preform, by which a large preform is stably produced and a bulk density of the preform is easily controlled.