Patents by Inventor Venkata Bhagavatula
Venkata Bhagavatula 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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Publication number: 20030044148Abstract: Disclosed is a dispersion controlled optical waveguide fiber, and telecommunication systems using such a waveguide fiber, in which the end to end total dispersion and total dispersion slope is controlled by varying the refractive index profile along the fiber length. The waveguide fiber includes length portions each of which is characterized by total dispersion having a magnitude and sign and total dispersion slope having a magnitude and sign. The magnitudes and signs of total dispersion and total dispersion slope of respective length portions are chosen to provide for the optical waveguide fiber a desired end to end total dispersion and total dispersion slope. An advantage is achieved in the present invention by designing the refractive index profiles of the length portions to have total dispersion and total dispersion slope of opposite sign.Type: ApplicationFiled: August 19, 2002Publication date: March 6, 2003Inventors: George E. Berkey, Venkata A. Bhagavatula, Lutfur Rahman, V. Srikant
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Patent number: 6510264Abstract: The present invention provides photonic devices utilized in optical telecommunications. The photonic devices include photosensitive bulk glass bodies which contain Bragg gratings, particularly with the ultraviolet photosensitive bulk glass bodies directing optical telecommunications wavelength range bands. Preferably the ultraviolet photosensitive bulk glass bodies are batch meltable alkali boro-alumino-silicate bulk glass bodies.Type: GrantFiled: June 5, 2001Date of Patent: January 21, 2003Assignee: Corning IncorporatedInventors: Venkata A. Bhagavatula, Nicholas F. Borrelli, Monica K. Davis, Edward F. Murphy
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Patent number: 6507438Abstract: An interference filter (10, 30, 50, 70, 90, 110, 130, 150, or 190) filters selected wavelengths by dividing an input beam into two or more intermediate beams having different optical path lengths and by recombining the intermediate beams into an output beam that is modified by interference between the intermediate beams. An optical path length difference generator (20, 40, 60, 80, 100, 120, 140, 160, or 200) varies the optical path lengths of the intermediate beams by changing the physical lengths of their paths or the refractive indices of the mediums in which they are conveyed. The optical path length generator (20) of one exemplary embodiment (10) includes a spacer plate (20) that is divided into elements (22 and 24) having different refractive indices for varying the optical path lengths of the intermediate beams.Type: GrantFiled: September 25, 2001Date of Patent: January 14, 2003Assignee: Corning IncorporatedInventor: Venkata A. Bhagavatula
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Publication number: 20030002788Abstract: The present invention features an optical component based on a wavelength-dispersive element in conjunction with reflective elements to provide wavelength-sensitive control multi-wavelength light signals such as wavelength division multiplexed (WDM) light signals. Both static reflective elements and movable (dynamic) reflective elements are described. Optical devices such as gain-flattening filters and dynamically configurable wavelength selective routers with built-in gain flattening filters are described.Type: ApplicationFiled: June 28, 2001Publication date: January 2, 2003Inventor: Venkata A. Bhagavatula
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Publication number: 20020176644Abstract: The invention relates to a polarization combiner/splitter. The polarization combiner/splitter includes a first ferrule, a first optical fiber assembly coupled to the first ferrule and a second optical fiber assembly coupled to the first ferrule. The polarization combiner/splitter also includes a walk-off crystal coupled to the first ferrule. A second ferrule is coupled to the walk-off crystal; and a third optical fiber assembly coupled to the second ferrule. The first optical fiber assembly includes a first fiber GRIN lens coupled to a first polarization mode maintaining optical waveguide fiber. The second optical fiber assembly includes a second fiber GRIN lens coupled to a second polarization mode maintaining optical waveguide fiber. The third optical fiber assembly includes a third fiber GRIN lens and a first single mode optical waveguide fiber.Type: ApplicationFiled: March 14, 2002Publication date: November 28, 2002Inventors: Venkata A. Bhagavatula, John Himmelreich, Gaeyoun Kim, Kamjula P. Reddy, Gregory E. Williams, Bryan J. Wolfe
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Publication number: 20020094181Abstract: A single mode optical waveguide fiber designed for high data rate, or WDM systems or systems incorporating optical amplifiers. The optical waveguide has a compound core having a central region and at least one annular region surrounding the central region. A distinguishing feature of the waveguide core is that the minimum refractive index of the central core region is less than the minimum index of the adjacent annular region.Type: ApplicationFiled: January 16, 2002Publication date: July 18, 2002Inventor: Venkata A. Bhagavatula
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Patent number: 6404964Abstract: A unitary dispersion managed waveguide fiber with distributed amplification and a system incorporating the waveguide fiber are disclosed. Total dispersion along the waveguide fiber changes from positive to negative along the length of the waveguide over a transmission wavelength range. Distributed amplification is provided by stimulated emission of a dilute concentration of a rare earth dopant in the waveguide, by Raman effects or by both.Type: GrantFiled: October 30, 2000Date of Patent: June 11, 2002Assignee: Corning IncorporatedInventors: Venkata A. Bhagavatula, Alan F. Evans
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Publication number: 20020015546Abstract: The present invention provides photonic devices utilized in optical telecommunications. The photonic devices include photosensitive bulk glass bodies which contain Bragg gratings, particularly with the ultraviolet photosensitive bulk glass bodies directing optical telecommunications wavelength range bands. Preferably the ultraviolet photosensitive bulk glass bodies are batch meltable alkali boro-alumino-silicate bulk glass bodies.Type: ApplicationFiled: June 5, 2001Publication date: February 7, 2002Inventors: Venkata A. Bhagavatula, Nicholas F. Borrelli, Monica K. Davis, Edward F. Murphy
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Publication number: 20020009261Abstract: A spherical lens formed by fusing a generally homogenous glass lens blank to the distal end of an optical fiber, heating and tensioning the lens blank to separate it in two segments with the segment attached to the optical fiber defining a tapered end, and heating the lens blank above its softening point so that the spherical lens forms. The lens blank is fabricated from a 4 mole percent borosilicate glass having a softening point less than that of the core of the optical fiber. The lens member defines a throat region adjacent the optical fiber whose cross-sectional dimension is substantially greater than the diameter of the optical fiber, but substantially less than the diameter of the spherical lens.Type: ApplicationFiled: March 19, 2001Publication date: January 24, 2002Inventors: Venkata A. Bhagavatula, John Himmelreich, Gregory E. Williams, Ljerka Ukrainczyk, Roberts S. Wagner
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Publication number: 20020005989Abstract: An interference filter (10, 30, 50, 70, 90, 110, 130, 150, or 190) filters selected wavelengths by dividing an input beam into two or more intermediate beams having different optical path lengths and by recombining the intermediate beams into an output beam that is modified by interference between the intermediate beams. An optical path length difference generator (20, 40, 60, 80, 100, 120, 140, 160, or 200) varies the optical path lengths of the intermediate beams by changing the physical lengths of their paths or the refractive indices of the mediums in which they are conveyed. The optical path length generator (20) of one exemplary embodiment (10) includes a spacer plate (20) that is divided into elements (22 and 24) having different refractive indices for varying the optical path lengths of the intermediate beams.Type: ApplicationFiled: September 25, 2001Publication date: January 17, 2002Applicant: Corning IncorporatedInventor: Venkata A. Bhagavatula
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Patent number: 6317265Abstract: An interference filter (10, 30, 50, 70, 90, 110, 130, 150, or 190) filters selected wavelengths by dividing an input beam into two or more intermediate beams having different optical path lengths and by recombining the intermediate beams into an output beam that is modified by interference between the intermediate beams. An optical path length difference generator (20, 40, 60, 80, 100, 120, 140, 160, or 200) varies the optical path lengths of the intermediate beams by changing the physical lengths of their paths or the refractive indices of the mediums in which they are conveyed. The optical path length generator (20) of one exemplary embodiment (10) includes a spacer plate (20) that is divided into elements (22 and 24) having different refractive indices for varying the optical path lengths of the intermediate beams.Type: GrantFiled: February 16, 2000Date of Patent: November 13, 2001Assignee: Corning IncorporatedInventor: Venkata A. Bhagavatula
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Patent number: 6259830Abstract: A resultant device and a method for making a frame structure for use as a poled optical device (10) includes providing a glass preform (30) having a poling area (12) and a waveguiding core area (16). At least one feedstock (24) is assembled into the waveguiding core area (16). The at least one feedstock (24) is separated from the poling area (12). The glass preform (30) and the at least one feedstock (24) are heated (36) and drawn into a smaller diameter (13) to form an optical waveguide.Type: GrantFiled: November 30, 1999Date of Patent: July 10, 2001Assignee: Corning, IncorporatedInventor: Venkata A. Bhagavatula
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Patent number: 6173588Abstract: An optical fiber having optical characteristics that vary along its length is made by assembling a plurality of cylindrical glass or soot tablets into or along a glass tablet alignment device, then fused into monolithic assembly. If desired, additional glass may be applied to the assembly before or after the fusing step. A vacuum is preferably applied during the fusing step. Each tablet preferably contains a core region, and it optionally contains a layer of cladding glass. Adjacent tablets are capable of forming optical fiber sections having different optical properties. Prior to consolidating the glass particles, chlorine preferably flows through or around the tablets and alignment device. The resultant draw blank can be drawn into a low loss optical fiber having short transition regions between adjacent areas of fiber. This method is particularly useful for making dispersion managed single-mode optical fibers.Type: GrantFiled: April 28, 1999Date of Patent: January 16, 2001Assignee: Corning IncorporatedInventors: George E. Berkey, Venkata A. Bhagavatula
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Patent number: 6137456Abstract: A flat screen autostereoscopic display for bright wide angle stereoscopic images employs a flat screen on which are displayed a light pattern such as a plurality of regularly spaced, thin, vertical light emitting lines. The light lines are formed through use of electrically switchable materials such as liquid crystal or electrochromic materials. A transmissive electronic display, e.g., a liquid crystal display, is located in front of the light lines. The display and light lines are arranged in such a way that an observer sees the light emitting lines through one set of pixels with the left eye and the same lines through a different set of pixels through the right eye. Methods and apparatus for the simultaneous formation of a two-dimensional image and a three-dimensional image on such a transmissive electronic display, and for moving or dragging the display area of the three-dimensional image from one location to another on said display, are also disclosed.Type: GrantFiled: February 3, 1999Date of Patent: October 24, 2000Assignee: Corning IncorporatedInventors: Venkata A. Bhagavatula, Robert L. Carlson, Robert G. Lindquist
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Patent number: 6046854Abstract: An interference filter (10, 30, 50, 70, 90, 110, 130, 150, or 190) filters selected wavelengths by dividing an input beam into two or more intermediate beams having different optical path lengths and by recombining the intermediate beams into an output beam that is modified by interference between the intermediate beams. An optical path length difference generator (20, 40, 60, 80, 100, 120, 140, 160, or 200) varies the optical path lengths of the intermediate beams by changing the physical lengths of their paths or the refractive indices of the mediums in which they are conveyed. The optical path length generator (20) of one exemplary embodiment (10) includes a spacer plate (20) that is divided into elements (22 and 24) having different refractive indices for varying the optical path lengths of the intermediate beams.Type: GrantFiled: July 6, 1998Date of Patent: April 4, 2000Assignee: Corning IncorporatedInventor: Venkata A. Bhagavatula
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Patent number: 6044191Abstract: A single-mode optical waveguide fiber designed to limit power penalty due to four wave mixing and a method of making the waveguide is disclosed. Variations in properties, e.g., radius or refractive index, of the waveguide fiber core provide a total dispersion which varies along the length of the waveguide. The algebraic sum of products of length times total dispersion is controlled to a pre-selected value for each waveguide fiber which makes up a system link Proper choice of total dispersion variation magnitude and sub-length results in a system link wherein a signal travels only short distances in waveguide portions having total dispersion near zero. However, the variation of the total dispersion provides a system link which has a pre-selected dispersive effect on the signal over a selected wavelength range. The dispersive effect on the signal can be chosen to be essentially zero. A number of techniques for fabricating DM fiber are also disclosed.Type: GrantFiled: November 3, 1998Date of Patent: March 28, 2000Assignee: Corning IncorporatedInventors: George E. Berkey, Venkata A. Bhagavatula, Peter C. Jones, Donald B. Keck, Yanming Liu, Robert A. Modavis, Alan J. Morrow, Mark A. Newhouse, Daniel A. Nolan
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Patent number: 5984747Abstract: Rib structures for containing plasma in electronic displays are formed by redrawing glass preform into fiber-like rib components. The rib components are then assembled to form rib/channel structures suitable for use in flat panel displays, such as plasma emissive displays, field emissive displays and plasma addressed liquid crystal displays.Type: GrantFiled: February 27, 1997Date of Patent: November 16, 1999Assignee: Corning IncorporatedInventors: Venkata A. Bhagavatula, Benjamin J. Garbowski, Chad B. Moore, Donald M. Trotter, Jr.
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Patent number: 5894537Abstract: A single-mode optical waveguide fiber designed to limit power penalty due to four wave mixing and a method of making the waveguide is disclosed. Variations in properties, e.g., radius or refractive index, of the waveguide fiber core provide a total dispersion which varies along the length of the waveguide. The algebraic sum of products of length times total dispersion is controlled to a pre-selected value for each waveguide fiber which makes up a system link. Proper choice of total dispersion variation magnitude and sub-length results in a system link wherein a signal travels only short distances in waveguide portions having total dispersion near zero. However, the variation of the total dispersion provides a system link which has a pre-selected dispersive effect on the signal over a selected wavelength range. The dispersive effect on the signal can be chosen to be essentially zero. A number of techniques for fabricating DM fiber are also disclosed.Type: GrantFiled: January 11, 1996Date of Patent: April 13, 1999Assignee: Corning IncorporatedInventors: George E. Berkey, Venkata A. Bhagavatula, Peter C. Jones, Donald B. Keck, Yanming Liu, Robert A. Modavis, Alan J. Morrow, Mark A. Newhouse, Daniel A. Nolan
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Patent number: 5887105Abstract: Disclosed is a dispersion managed optical waveguide fiber. The power loss due to four wave mixing is kept low by making the waveguide from sub-lengths of fiber which have non-zero dispersion. The sign of the total dispersion of the sub-lengths is made to alternate along the length of the waveguide, thereby allowing the total dispersion of the waveguide to be managed to a pre-selected target value. It has been discovered that the best performance is obtained when the zero dispersion wavelengths of the sub-lengths are widely and asymmetrically separated. Advantages are realized when the core refractive index profile is changed for sub-lengths having total dispersion of different sign.Type: GrantFiled: April 2, 1998Date of Patent: March 23, 1999Assignee: Corning IncorporatedInventors: Venkata A. Bhagavatula, Dipakbin Q. Chowdhury
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Patent number: RE37680Abstract: A single mode optical waveguide fiber designed for high data rate, or WDM systems or systems incorporating optical amplifiers. The optical waveguide has a compound core having a central region and at least one annular region surrounding the central region. A distinguishing feature of the waveguide core is that the minimum refractive index of the central core region is less than the minimum index of the adjacent annular region. A relatively simple profile design has the characteristics of ease in manufacturing together with, flexibility in tailoring Dw to yield a preselected zero dispersion wavelength, dispersion magnitude over a target wavelength range, and dispersion slope. The simplicity of profile gives reduced polarization mode dispersion.Type: GrantFiled: March 17, 1999Date of Patent: April 30, 2002Assignee: Corning IncorporatedInventor: Venkata A. Bhagavatula