Patents by Inventor David John DiGiovanni
David John DiGiovanni has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6826341Abstract: Optical fibers are described that exhibit reduced splice loss. Further described are techniques for fabricating optical fibers exhibiting reduced splice loss. One described fiber includes a plurality of regions, one region having a higher viscosity and the other region having a lower viscosity, such that when the fiber is drawn under tension, a strain is frozen into the higher viscosity region. A lower viscosity buffer layer is sandwiched between the higher viscosity region and the lower viscosity region. The buffer layer isolates the lower viscosity region from changes in refractive index in the higher viscosity region arising from a change in the strain frozen into the higher viscosity region.Type: GrantFiled: November 4, 2002Date of Patent: November 30, 2004Assignee: Fitel USA Corp.Inventors: David John DiGiovanni, Peter Mikal Holmblad, Torben E. Veng, Andrew D. Yablon
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Publication number: 20040228590Abstract: The specification describes a technique for drawing circular core multimode optical fiber using twist during draw to increase fiber bandwidth.Type: ApplicationFiled: February 25, 2004Publication date: November 18, 2004Inventors: David John DiGiovanni, Frank Vincent DiMarcello, XinLi Jiang, George E. Oulundsen, Sandeep Prabhakar Pandit
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Patent number: 6785472Abstract: A fiber-optic WDM ring carries communication traffic among a plurality of nodes, each node associated with respective subscriber premises. Remote gain is provided in at least one link of the ring. In specific embodiments of the invention, the remote gain is applied preferentially to those wavelength channels most in need of amplification. In specific embodiments of the invention, the remote gain is Raman gain.Type: GrantFiled: June 15, 1999Date of Patent: August 31, 2004Assignee: Lucent Technologies Inc.Inventors: Laura Ellen Adams, Jon Anderson, Robert Mario Broberg, David John DiGiovanni, Karsten Rottwitt
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Patent number: 6768849Abstract: Systems and methods are described for fabricating a varying-waveguide optical fiber. In one described method, a preform is fabricated having a core and at least one cladding region. The cladding region has a higher viscosity and the core region has a lower viscosity. The relative viscosities of the cladding region and core are chosen such that, when tension is applied to an optical fiber drawn from the preform, the applied tension is primarily borne by the cladding region thereby causing a viscoelastic strain to be frozen into the cladding region, while creating a minimal viscoelastic strain in the core. The method further includes drawing the preform into an optical fiber under an applied tension, such that a viscoelastic strain is frozen into the cladding region the frozen-in viscoelastic strain decreasing the cladding region refractive index.Type: GrantFiled: July 3, 2002Date of Patent: July 27, 2004Assignee: Fitel USA Corp.Inventors: David John DiGiovanni, Andrew D. Yablon, Man Fei Yan
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Patent number: 6768847Abstract: A dispersion compensating fiber and module are described for controlling residual dispersion in a dispersion compensated system. The dispersion compensating fiber is designed with dispersion curve having an inflection point at a wavelength near the optical transmission operating wavelength region. The dispersion curve, having an inflection point near the operating wavelength region, produces a relative dispersion slope that closely matches the relative dispersion slope of the transmission fiber over a relatively wide bandwidth surrounding the operating wavelength region.Type: GrantFiled: March 15, 2002Date of Patent: July 27, 2004Assignee: Fitel USA Corp.Inventors: David John DiGiovanni, William A. Reed, Man F. Yan, Lars Gruner-Nielsen, Susanne Dyrbol
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Patent number: 6735985Abstract: The specification describes a technique for drawing circular core multimode optical fiber using twist during draw to increase fiber bandwidth.Type: GrantFiled: December 20, 2001Date of Patent: May 18, 2004Assignee: Furukawa Electric North America IncInventors: David John DiGiovanni, Frank Vincent DiMarcello, XinLi Jiang, George E. Oulundsen, Sandeep Prabhakar Pandit
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Publication number: 20040086243Abstract: Optical fibers are described that exhibit reduced splice loss. Further described are techniques for fabricating optical fibers exhibiting reduced splice loss. One described fiber includes a plurality of regions, one region having a higher viscosity and the other region having a lower viscosity, such that when the fiber is drawn under tension, a strain is frozen into the higher viscosity region. A lower viscosity buffer layer is sandwiched between the higher viscosity region and the lower viscosity region. The buffer layer isolates the lower viscosity region from changes in refractive index in the higher viscosity region arising from a change in the strain frozen into the higher viscosity region.Type: ApplicationFiled: November 4, 2002Publication date: May 6, 2004Applicant: Fitel USA Corp.Inventors: David John DiGiovanni, Peter Mikal Holmblad, Torben E. Veng, Andrew D. Yablon
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Publication number: 20040031290Abstract: Techniques are described for fabricating a preform from a soot body. In one described technique, a soot body is loaded into a substrate tube, and the position of the soot body is stabilized within the tube. The tube is then rotated around its longitudinal axis. Heat is applied from a heat source to the substrate tube at a first end of the soot body to cause the first end of the soot body to begin to sinter and to cause the substrate tube to begin to at least partially collapse around the sintered portion of the soot body. The heat source is then advanced along the substrate tube and the soot body to cause a progressive sintering of the soot body, and to cause a progressive, at least partial, collapse of the substrate tube around the sintered portion of the soot body.Type: ApplicationFiled: August 16, 2002Publication date: February 19, 2004Applicant: Fitel USA Corp.Inventors: David John DiGiovanni, Kyunghwan Oh
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Publication number: 20040013374Abstract: Systems and techniques are described for fabricating a low-loss, high-strength optical transmission line. In one described technique, a first fiber is spliced to a second fiber at a splice point. The spliced fibers are loaded into a heat treatment station, where a gas torch flame is used to thermally treat a splice region including the splice point, with the thermal treatment reducing splice loss between the first and second fibers. While heating the splice region, a dry gas is purged around the torch flame during the heat treatment process to avoid water at the surface of the spliced fibers. According to further described techniques, a purging gas is fed to the torch flame to purge dust particles from the flame, and after the heat treatment has been completed, the torch flame is used to restore the glass surface of the spliced fibers. Additionally described are torch assemblies for fabricating low-loss, high-strength optical fiber transmission lines.Type: ApplicationFiled: July 17, 2002Publication date: January 22, 2004Applicant: Fitel USA Corp.Inventors: David John DiGiovanni, Torben E. Veng
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Publication number: 20040005128Abstract: Systems and methods are described for fabricating a varying-waveguide optical fiber. In one described method, a preform is fabricated having a core and at least one cladding region. The cladding region has a higher viscosity and the core region has a lower viscosity. The relative viscosities of the cladding region and core are chosen such that, when tension is applied to an optical fiber drawn from the preform, the applied tension is primarily borne by the cladding region thereby causing a viscoelastic strain to be frozen into the cladding region, while creating a minimal viscoelastic strain in the core. The method further includes drawing the preform into an optical fiber under an applied tension, such that a viscoelastic strain is frozen into the cladding region the frozen-in viscoelastic strain decreasing the cladding region refractive index.Type: ApplicationFiled: July 3, 2002Publication date: January 8, 2004Applicant: Fitel USA Corp.Inventors: David John DiGiovanni, Andrew D. Yablon, Man Fei Yan
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Patent number: 6658183Abstract: The invention involves providing a microstructured fiber having a core region, a cladding region, and one or more axially oriented elements (e.g., capillary air holes) in the cladding region. A portion of the microstructured fiber is then treated, e.g., by heating and stretching the fiber, such that at least one feature of the fiber microstructure is modified along the propagation direction, e.g., the outer diameter of the fiber gets smaller, the axially oriented elements get smaller, or the axially oriented elements collapse. The treatment is selected to provide a resultant fiber length that exhibits particular properties, e.g., mode contraction leading to soliton generation, or mode expansion. Advantageously, the overall fiber length is designed to readily couple to a standard transmission fiber, i.e., the core sizes at the ends of the length are similar to a standard fiber, which allows efficient coupling of light into the microstructured fiber length.Type: GrantFiled: October 20, 2000Date of Patent: December 2, 2003Assignee: Lucent Technologies Inc.Inventors: Juhi Chandalia, David John DiGiovanni, Benjamin John Eggleton, Sandra Greenberg Kosinski, Xiang Liu, Robert Scott Windeler, Chunhui Xu
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Patent number: 6654522Abstract: The invention involves providing a microstructured fiber having a core region, a cladding region, and one or more axially oriented elements (e.g., capillary air holes) in the cladding region. A portion of the microstructured fiber is then treated, e.g., by heating and stretching the fiber, such that at least one feature of the fiber microstructure is modified along the propagation direction, e.g., the outer diameter of the fiber gets smaller, the axially oriented elements get smaller, or the axially oriented elements collapse. The treatment is selected to provide a resultant fiber length that exhibits particular properties, e.g., mode contraction leading to soliton generation, or mode expansion. Advantageously, the overall fiber length is designed to readily couple to a standard transmission fiber, i.e., the core sizes at the ends of the length are similar to a standard fiber, which allows efficient coupling of light into the microstructured fiber length.Type: GrantFiled: April 23, 2002Date of Patent: November 25, 2003Assignee: Lucent Technologies Inc.Inventors: Juhi Chandalia, David John DiGiovanni, Benjamin John Eggleton, Sandra Greenberg Kosinski, Robert Scott Windeler
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Publication number: 20030206697Abstract: Embodiments of the invention include a singlemode optical fiber having an antimony (Sb) doped core region, a suitable cladding region formed on the core region, and one or more gratings written in the optical fiber. Optical fibers manufactured according to embodiments of the invention provide faster growth of grating strength, higher thermal stability, and longer photosensitive wavelength compared to conventional Ge doped silica optical fibers. The optical fiber is fabricated for applications such as fiber grating applications where the index of the core is modulated by UV radiation. Also, the addition of Sb in the core region of the singlemode optical fiber provides higher temperature (e.g., greater than 100° C.) applications of fiber gratings and a reduced degradation of the band rejection efficiency. Also, the optical fibers are more conducive to direct and non-destructive grating writing over polymer jackets with a longer photosensitive wavelength in the UV range.Type: ApplicationFiled: July 4, 2001Publication date: November 6, 2003Inventors: Robert Michael Atkins, David John DiGiovanni, Kyunghwan Oh, William Alfred Reed, Paul Stephen Westbrook, Robert Scott Windeler
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Publication number: 20030174981Abstract: A dispersion compensating fiber and module are described for controlling residual dispersion in a dispersion compensated system. The dispersion compensating fiber is designed with dispersion curve having an inflection point at a wavelength near the optical transmission operating wavelength region. The dispersion curve, having an inflection point near the operating wavelength region, produces a relative dispersion slope that closely matches the relative dispersion slope of the transmission fiber over a relatively wide bandwidth surrounding the operating wavelength region.Type: ApplicationFiled: March 15, 2002Publication date: September 18, 2003Applicant: Fitel USA Corp.Inventors: David John DiGiovanni, William A. Reed, Man F. Yan, Lars Gruner-Nielsen, Susanne Dyrbol
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Publication number: 20030128942Abstract: The specification describes a technique for drawing circular core multimode optical fiber using twist during draw to increase fiber bandwidth.Type: ApplicationFiled: December 20, 2001Publication date: July 10, 2003Inventors: David John DiGiovanni, Frank Vincent DiMarcello, XinLi Jiang, George E. Oulundsen, Sandeep Prabhakar Pandit
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Patent number: 6587625Abstract: Applicants have discovered an apparatus and method effective for use in rendering an optical fiber resistant to losses caused by high-radiation environments such as in outerspace. The apparatus comprises an optical fiber, a housing surrounding the optical fiber defining an enclosed space between the exterior surface of the fiber and the housing, and a concentration of deuterium or hydrogen gases disposed within the enclosed space.Type: GrantFiled: February 15, 2000Date of Patent: July 1, 2003Assignee: Lucent Technologies Inc.Inventors: Joseph A. Abate, Robert George Ahrens, David John DiGiovanni, Michael James LuValle, Herman Melvin Presby, Robert Scott Windeler
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Patent number: 6542679Abstract: Our method of making high bandwidth silica-based multimode optical fiber comprises provision of a non-circular preform, and drawing fiber of chiral structure from the preform. The non-circular preform can be made by maintaining the inside of the tubular preform under reduced pressure during at least part of the collapse, resulting in a non-circular core and cladding. It can also be made by removal (e.g., by grinding or plasma etching) of appropriate portions of the preform, resulting in a circular core and non-circular cladding. In the latter case, fiber is drawn at a relatively high temperature such that, due to surface tension, the cladding assumes substantially circular shape and the core assumes a non-circular shape. The chiral structure is imposed on the fiber in any appropriate way, e.g., by twisting during fiber drawing the fiber alternately in clockwise and couterclockwise sense relative to the preform.Type: GrantFiled: May 1, 2001Date of Patent: April 1, 2003Assignee: Lucent Technologies Inc.Inventors: David John DiGiovanni, Steven Eugene Golowich, Sean L. Jones, William Alfred Reed
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Patent number: 6513994Abstract: The specification describes a technique for evaluating optical fiber splices. The essence of the technique involves detecting thermal power emanating from the fiber splice as the result of absorption of the light carried by the fiber. The technique is particularly suited for cladding pumped lasers wherein the splicing operation may introduce excessive absorption of pump laser radiation and excessive heating at the splice locale.Type: GrantFiled: April 28, 2000Date of Patent: February 4, 2003Assignee: Fitel USA Corp.Inventors: David John DiGiovanni, John Edwin Graebner, Sun-Young John Kwak
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Publication number: 20020154874Abstract: An optical waveguide comprising a silica structure and a number of radiation shielding dopant atoms. At least some of the radiation shielding dopant atoms are chemically bonded with at least some of the constituents of silica structure. As such, the radiation shielding dopants are fixed within the silica structure to shield the optical waveguide from at least one of alpha-, beta-, gamma-, x-, and neutron-radiation.Type: ApplicationFiled: April 20, 2001Publication date: October 24, 2002Inventors: Robert G. Ahrens, David John DiGiovanni, Robert Scott Windeler
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Publication number: 20020114574Abstract: The invention involves providing a microstructured fiber having a core region, a cladding region, and one or more axially oriented elements (e.g., capillary air holes) in the cladding region. A portion of the microstructured fiber is then treated, e.g., by heating and stretching the fiber, such that at least one feature of the fiber microstructure is modified along the propagation direction, e.g., the outer diameter of the fiber gets smaller, the axially oriented elements get smaller, or the axially oriented elements collapse. The treatment is selected to provide a resultant fiber length that exhibits particular properties, e.g., mode contraction leading to soliton generation, or mode expansion. Advantageously, the overall fiber length is designed to readily couple to a standard transmission fiber, i.e., the core sizes at the ends of the length are similar to a standard fiber, which allows efficient coupling of light into the microstructured fiber length.Type: ApplicationFiled: April 23, 2002Publication date: August 22, 2002Inventors: Juhi Chandalia, David John DiGiovanni, Benjamin John Eggleton, Sandra Greenberg Kosinski, Robert Scott Windeler