Corning Incorporated

James C Fajardo

James Andrew West

Michael Thomas Gallagher

Douglas Clippinger Allan

Karl William Koch, Iii

Phong Diep

Nicholas Francis Borrelli

Daniel Aloysius Nolan

Daniel Warren Hawtof

Dale Robert Powers

Adam J G Ellison

Stuart Gray

Keith Leonard House

John T Brown

Gang Qi

Lisa C Chacon

Ming-Jun Li

George Edward Berkey

Natesan Venkataraman

Qi Wu

Anping Liu

Richard Michael Fiacco

Luis Alberto Zenteno

Peter Gerard Wigley

Carlton Maurice Truesdale

V Srikant

Glenn E Kohnke

Monica K Davis

Thomas Roger Cook

Michael J Hackert

Selina G Farwell

(Ying) Lisa Peng

Gary Paul Granger

The present invention provides devices and methods for Raman amplification and dispersion compensation. According to one embodiment of the present invention, a dispersion compensating device includes a dispersion compensating fiber having a dispersion more negative than about &#x2212;50 ps/nm/km over a wavelength range of about 1555 nm to about 1615 nm; a Raman gain fiber having a dispersion more positive than about &#x2212;40 ps/nm/km over a wavelength range of about 1555 nm to about 1615 nm; and a pump source operatively coupled to the dispersion compensating fiber and the Raman gain fiber, the pump source operating at a pump wavelength, wherein the dispersion compensating fiber has a Raman Figure of Merit at the pump wavelength, and wherein the Raman gain fiber has a Raman Figure of Merit at least about equivalent to the Raman Figure of Merit of the dispersion compensating fiber, and wherein the dispersion compensating fiber and the Raman gain fiber are arranged in series between the input and the output of the device. The device provides higher Raman gain than a conventional Raman-pumped dispersion compensating device.

Devices and method for Raman amplification and dispersion compensation

Devices and methods for raman amplification and dispersion compensation

The present invention relates to a microstructured optical fiber including a photonic band gap-guided core; and at least one index-guided core. Another embodiment of the present invention relates to a microstructured optical fiber including a set of main cores; a microstructured region surrounding the set of main cores; and at least alignment core, the alignment cores having substantially different optical propagation properties than the main cores. The present invention also includes methods for coupling, monitoring, and locating discontinuities in the fibers of the present invention.

Multiple core microstructured optical fibers and methods using said fibers

Disclosed is a single mode optical waveguide fiber having a low cut off wavelength, and mode field diameter and bend resistance similar to step index single mode optical waveguide fiber designed for use at 1310 nm. By including a clad region of raised refractive index spaced apart from the core region of the single mode optical waveguide fiber, the cut off wavelength can be reduced to 850 nm. The single mode optical waveguide fiber in accord with the invention may also have a core region having a reduced refractive index on centerline surrounded by a region of higher refractive index and a clad region which is substantially uniform. The single mode optical waveguide fiber is thus ideally suited for use with the low cost, reliable VCSEL operating at 850 nm, a Fabry-Perot laser operating at 1310 nm, or a distributed feedback laser operating at 1550 nm thereby enabling low cost, easily installed, home access portions of the broadband telecommunications system.

Optical waveguide fiber for local access

An optically-active air-clad fiber () includes a core () that facilitates doping with an ion optically excitable and having a three-level optical transition when pumped at a first end () of an optical cavity () by a multimode pump source () at a pump wavelength () for lasing at a signal wavelength () different than the pump wavelength () at a second end () of the optical cavity (), the core () having a refractive index, wherein the core () is transformed from the first end to proximate the second end () thereof such that the optically-active fiber () is multimode at the pump wavelength proximate to the first end (), and is single-mode at the signal wavelength proximate to the second end (). An air-clad () surrounds at least one portion of the core () and has a lower effective refractive index than the refractive index of the core ().

Three-level air-clad rare-earth doped fiber laser/amplifier

An isotopically-altered, silica based optical fiber is provided having lower losses, broader bandwidth, and broader Raman gain spectrum characteristics than conventional silica-based fiber. A heavier, less naturally abundant isotope of silicon or oxygen is substituted for a lighter, more naturally abundant isotope to shift the infrared absorption to a slightly longer wavelength. In one embodiment, oxygen-18 is substituted for the much more naturally abundant oxygen-16 at least in the core region of the fiber. The resulting isotopically-altered fiber has a minimum loss of 0.044 dB/km less than conventional fiber, and a bandwidth that is 17 percent broader for a loss range between 0.044-0.034 dB/km. The fiber may be easily manufactured with conventional fiber manufacturing equipment by way of a plasma chemical vapor deposition technique. When a 50 percent substitution of oxygen -18 for oxygen-16 is made in the core region of the fiber, the Raman gain spectrum is substantially broadened.

Isotopically altered optical fiber

A microstructured optical fiber is described. The microstructured optical fiber comprises an inner region and an outer region. The inner region includes an inner material and a plurality of holes formed in the inner material. The outer region surrounds the inner region, and includes an outer material. The softening point temperature of the inner material is greater than the softening point temperature of the outer material by at least about 50&#xb0; C. Microstructured optical fiber preforms and methods for making the microstructured optical fibers are also described. The microstructured optical fiber may be made to have substantially undistorted holes in the inner region.

Microstructured optical fibers and preforms and methods for fabricating microstructured optical fibers

A method for manufacturing optical fiber with enhanced photosensitivity comprising the step of: forming a molten layer of glass and drawing a fiber from the molten layer of glass at a temperature of between about 1900&deg; C. and 1995&deg; C. Draw tension can be adjusted to attain the desired draw speed.

Making a glass optical fiber with a grating thereon

Disclosed is a photonic band-gap crystal waveguide having the physical dimension of the photonic crystal lattice and the size of the defect selected to provide for optimum mode power confinement to the defect. The defect has a boundary which has a characteristic numerical value associated with it. The ratio of this numerical value to the pitch of the photonic crystal is selected to avoid surface modes found to exist in certain configurations of the photonic band-gap crystal waveguide. Embodiments in accord with the invention having circular and hexagonal defect cross sections are disclosed and described. A method of making the photonic band-gap crystal waveguide is also disclosed and described.

Optimized defects in band-gap waveguides

An isotopically-altered, silica based optical fiber is provided having lower losses, broader bandwidth, and broader Raman gain spectrum characteristics than conventional silica-based fiber. A heavier, less naturally abundant isotope of silicon or oxygen is substituted for a lighter, more naturally abundant isotope to shift the infrared absorption to a slightly longer wavelength. In one embodiment, oxygen-18 is substituted for the much more naturally abundant oxygen-16 at least in the core region of the fiber. The resulting isotopically-altered fiber has a minimum loss of 0.044 dB/km less than conventional fiber, and a bandwidth that is 17 percent broader for a loss range between 0.044-0.034 dB/km. The fiber may be easily manufactured with conventional fiber manufacturing equipment by way of a plasma chemical vapor deposition technique. When a 50 percent substitution of oxygen-18 for oxygen-16 is made in the core region of the fiber, the Raman gain spectrum is substantially broadened.

Disclosed is an optical waveguide fiber preform and an optical waveguide fiber drawn therefrom, in which the density and thus the effective refractive index of the clad layer is caused to change in a pre-selected way axially along the waveguide preform and the associated waveguide fiber. The axial change in density of the clad layer is due to the fraction of the clad volume that is air or a glass of a composition different from that of the base clad glass. The axially variation in clad index changes the signal mode power distribution, thereby changing key waveguide fiber parameters such as magnitude and sign of dispersion, cut off wavelength and zero dispersion wavelength. The invention includes methods of making the structures having an axially varying clad layer. The invention relates to preforms and associated waveguide fibers which guide light due to difference in refractive index between core and clad. The invention also contemplates preforms, in which the waveguide fibers drawn therefrom, guide light due to the photonic crystal structure of all of the clad layer length or segments of the clad layer length.

Waveguides having axially varying structure

An optical splice joint and splicing process are provided for joining an end portion of a microstructured optical fiber having a microstructure formed from an array of holes, and a conventional optical fiber. The optical splice joint is formed from a fused portion of opposing end portions of the microstructured optical fiber and optical fiber, wherein the microstructured optical fiber is surrounded by a jacket that is at least 1.6 times thicker along its radius than the microstructure, and has a tensile strength of at least 30 Kpsi with an optical loss of less than 0.30 dB, and relatively little shrinkage (i.e., about 30%) of the holes forming the microstructure. The splice joint is formed by aligning end portions of the microstructured optical fiber and the optical fiber, in a fusion splicer, and applying fusion heat to the fiber ends in a two step process with a low current arc that is offset with respect to the end of the microstructured optical fiber.

Splice joint and process for joining a microstructured optical fiber and a conventional optical fiber

Optical fiber structures having at least two cores, whether unitary or separable, may be fabricated by controlling the placement of the cores prior to final processing to make the multi-core fiber structure. When the fiber is to be separable, at least two performs are attached, and the attachment height between adjacent canes is controlled to allow separation to be realized (or attachment to be maintained there between) anywhere along the separable multi-core fiber. These canes are then drawn together to form a desired composite fiber, either or both ends of which may be separated to allow for individual manipulation of fiber ends. The separable multi-core fiber may be utilized to fabricate a dual-port or multi-port optical component in which an input and an output (or multiple input/output) fibers are attached to the component, and the exposed distal ends of the separable multi-core fiber are thereafter separated from one another (even after the entire device is assembled and packaged) to provide separated waveguides for pigtailing or splicing to input or output fibers (or other planar or micro-optic components).

Growing community of inventors

Painted Post, NY, United States of America

James C Fajardo