Corning Incorporated

Other

V Srikant

George Edward Berkey

Michael B Cain

Sergey Yurevich Ten

Jeffery Scott Stone

Lei Jiang

Scott Robertson Bickham

Snigdharaj Kumar Mishra

Gang Qi

Daniel Aloysius Nolan

Daniel Warren Hawtof

Dale Robert Powers

Pamela A Hajcak

Upendra H Manyam

Dana Craig Bookbinder

Ming-Jun Li

Pushkar Tandon

Steven Bruce Dawes

Alan Frank Evans

James Andrew West

Richard Michael Fiacco

Eric John Mozdy

Keith Leonard House

James C Fajardo

Cynthia Baker Giroux

Shiva Kumar

Gerald E Burke

Jan Conradi

Rachel S Mozdy

Julie E Caplen

Jean-Philippe J deSandro

Martin R Williams

David P Machewirth

Methods, apparatus and precursors for producing substantially water-free silica soot, preforms and glass. The methods and apparatus make substantially water-free fused silica preforms or glass by removing water as a reaction product, removing water from the atmosphere, removing water from the transport process, or combinations thereof. In a first embodiment, substantially water-free soot, preforms or glass are achieved by using a hydrogen-free fuel, such as carbon monoxide, in the deposition process. In another embodiment, a soot producing burner has parameters that enable operation on a substantially hydrogen-free fuel. End burners, which minimize water production, are also described. Such water-free methods are useful in depositing fluorine-doped soot because of the low water present and the efficiency in which fluorine is incorporated. In another embodiment, glassy barrier layer methods and apparatus are described for minimizing dopant migration, especially fluorine. Laser and induction methods and apparatus for forming the barrier layer are depicted. A chlorine, fluorine and silica precursor, such as chlorofluorosilane, may be utilized to form fluorinated soot. Other methods and apparatus are directed to combinations of conventional and substantially water-free processes. One embodiment is directed to combustion enhancing additives for addition to the substantially hydrogen-free fuels. The methods and apparatus in accordance with the invention are particularly useful for producing photomask substrates and optical fiber preforms.

Method of forming optical fiber preforms

An optical signal transmission line includes a first fiber adapted to guide an optical signal therethrough and having a first &#x3ba;, a second fiber adapted to guide the optical signal therethrough and having a second &#x3ba; of less than or equal to about 100 nm at a wavelength of 1550 nm, and a &#x3ba; compensating fiber adapted to guide the optical signal therethrough and having a third &#x3ba; of greater than or equal to about 60 nm at a wavelength of 1550 nm. The first fiber, the second fiber and the &#x3ba; compensating fiber are in optical communication, thereby defining an optical transmission line having a total dispersion and a total dispersion slope. The first &#x3ba;, the second &#x3ba; and the third &#x3ba; cooperate such that the total dispersion is within the range of about 1.0 ps/nm-km&#x2267;total dispersion&#x2267;about &#x2212;1.0 ps/nm-km at a wavelength of 1550 nm, and the total dispersion slope is within the range of about 0.02 ps/nm-km&#x2267;total dispersion slope&#x2267;about &#x2212;0.02 ps/nm-km at a wavelength of 1550 nm.

Optical transmission line and optical transmission system utilizing same

Disclosed is a fiber optic module containing one or more optical fibers having an attenuator formed in the output end of the fibers to filter out unwanted higher order modes. The optical fibers are typically gain fibers or dispersion compensating fibers, and the attenuator consists of a coil, or a series of bends, of sufficient number and bend radius that higher order modes are reduced below a desired level.

Optical fiber module having reduced multi-path interference

Disclosed is a dispersion compensating and dispersion slope compensating single mode optical waveguide fiber. The refractive index profiles of waveguide fibers in accord with the invention are disclosed and described. These index profiles provide a waveguide fiber having negative total dispersion and negative total dispersion slope so that a standard waveguide fiber is compensated over an extended wavelength range. A telecommunications link using the fiber in accord with the invention is also disclosed and described. A standard fiber to compensating fiber length ratio in the range of 1:1 to 3:1 is shown to give optimum link performance with respect to limiting non-linear dispersion effects.

Dispersion slope compensating optical waveguide fiber

Disclosed is a dispersion compensating optical fiber that includes a refractive index profile selected to provide dispersion at 1550 nm of between &minus;90 and &minus;150 ps/nm/km; dispersion slope at 1550 nm of less than &minus;1.5 ps/nm /km; and kappa of between 40 and 95. The profile preferably has a core surrounded by a cladding layer of refractive index &Dgr; , and at least three radially adjacent regions including a central core region having &Dgr;1, a moat region having a refractive index &Dgr;2, and an annular ring region having a refractive index &Dgr;3, wherein &Dgr;1>&Dgr;3>&Dgr;c>&Dgr;2.

Dispersion compensating optical fiber

The present invention is directed to methods of producing soot used in the manufacture of optical waveguides. Both non-aqueous liquid reactants and aqueous solutions containing one or more salts are delivered through an atomizing burner assembly to form a homogenous soot stream containing the oxides of the selected elements contained within the non-aqueous liquid reactant and the aqueous solution. The resulting multi-component soot is collected by conventional methods to form preforms used in the manufacture of optical waveguide fibers. Preforms formed by the methods are also disclosed.

Methods of manufacturing soot for optical fiber preforms and preforms made by the methods

Disclosed are refractive index profiles for total dispersion compensating optical waveguide fibers for use in high data rate, long length telecommunications systems. The optical waveguide fibers in accord with the invention provide substantially equal compensation of total dispersion over a range of wavelengths, thus facilitating wavelength division multiplexed systems. Also disclosed are spans of optical waveguide fiber that include a length of transmission fiber together with a length of the compensating fiber. The spans are joined end to end in series arrangement to form the optical waveguide fiber part of a telecommunication system.

Dispersion slope compensating optical fiber

A single mode dispersion and dispersion slope compensating optical fiber includes a central core segment, a depressed moat segment, an annular ring segment, and a cladding layer. Each of the segments of the fiber have a relative refractive index that are selected to provide negative dispersion at a wavelength of within the range of about 1530 nm to about 1620 nm, negative dispersion slope at a wavelength of within the range of about 1530 nm to about 1620 nm, a kappa value of within the range of 40 to about 60 at a wavelength of about 1550 nm, and a fiber cut-off wavelength of less than about 1650 nm, and more preferably less than 1550 nm.

Single mode dispersion compensating optical fiber

Dispersion managed fibers which preferably have a central core region, a moat region, and a ring region are provided. The central core region preferably has an alpha profile with an alpha value preferably less than about 2.3. The moat region preferably includes four sub-regions, namely, a first sub-region ( ) in which the index of refraction decreases, a second sub-region ( ) in which the index of refraction increases substantially linearly, a fourth sub-region ( ) in which the index of refraction again increases substantially linearly, and a third sub-region ( ) which serves as a transition region which smoothly connects the third and fourth substantially linear sub-regions. The dispersion managed fibers preferably have the following properties: (a) they exhibit reduced sensitivity to manufacturing variabilities, (b) they have relatively small changes in mode field diameter at the junctions between fiber sections having positive dispersions and fiber sections having negative dispersions, and/or (c) they can be readily manufactured using the tablet method.

Dispersion managed fibers having reduced sensitivity to manufacturing variabilities

An optical fiber and method of making, wherein the optical fiber alternates between regions having different diameters along its length, wherein the refractive index of said blank and the diameters of said fiber are chosen to result in a fiber having alternating regions of positive and negative dispersion at a wavelength which is greater than 1480 nm, yet preferably has a low net dispersion and dispersion slope. A preferred such profile consists of a core region surrounded by a cladding region, said core region comprised of an central core region which is updoped with respect to said cladding region, said central core region surrounded by a moat region which is downdoped with respect to said cladding region, and said moat region is surrounded by an annular ring region which is updoped with respect to said cladding region. In addition, a family of profiles is presented which may be used to produce very low dispersion slope fibers. When used in conjunction with alternating positive and negative dispersion regions, lower net dispersion slope can be achieved. Alternatively, the family of profiles is useful in conventional WDM applications.

Low dispersion slope fiber

Disclosed is a dispersion compensating optical fiber that includes a core surrounded by a cladding layer of refractive index n . The core includes at least three radially adjacent regions, a central core region, a moat region having a refractive index n that is sufficiently lower than n such that &Dgr; &lE;&minus;0.4%, and a ring region. As the ring region exhibits sufficiently high refractive index at a sufficiently long distance from the outer edge of the moat region, the fiber can exhibit low values of negative dispersion slope at low values of negative dispersion and yet exhibit good bending loss. This ring region is also capable of imparting to the fiber a relatively high cutoff wavelength, so that the present invention is particularly well suited for use in L-band systems. A particularly suitable fiber has an index profile in which that part of the ring region at the transition between the moat and the ring region has a refractive index such that its delta value is close to zero. Also disclosed is a method of forming the fiber of the present invention.

Dispersion compensating fiber

An optical amplifier site comprising: (i) a distributed Raman amplifier providing a first signal gain level; (ii) an optical amplifier located downstream from the distributed Raman amplifier, the optical amplifier being indirectly coupled to the distributed Raman amplifier, the optical amplifier including a first amplification medium, providing a second signal gain level; (iii) at least one optical signal loss element located between the distributed Raman amplifier and the optical amplifier and, contributing at least 0.5 dB optical loss to the amplifier site; (iv) a second amplification medium located down-stream from the first amplification medium; and (v) at least another one optical signal loss element, this at least another one optical signal loss element being located between said first amplification medium and said second amplification medium.

Optical amplifier site with reduced noise and transmission system utilizing such

Disclosed is a dispersion compensating optical fiber that includes a core surrounded by a cladding layer of refractive index &Dgr; . The core includes at least three radially adjacent regions, a central core region having &Dgr; a moat region having a refractive index &Dgr; and an annular ring region having a refractive index &Dgr; such that &Dgr; >&Dgr;c>&Dgr; The fiber exhibits a dispersion at 1550 which is less than &minus;30 ps/nm/km, and a &kgr; value obtained by dividing the dispersion value by the dispersion slope which is between 40 and 100.

A cylindrical glass body having a low water content centerline region and method of manufacturing such a cylindrical glass body for use in the manufacture of optical waveguide fiber is disclosed. The centerline region of the cylindrical glass body has a water content sufficiently low such that an optical waveguide fiber made from the cylindrical glass body of the present invention exhibits an optical attenuation of less than about 0.35 dB/km, and preferably less than about 0.31 dB/km at a measured wavelength of 1380 nm. A low water content plug used in the manufacture of such a cylindrical glass body, an optical waveguide fiber having a low water peak, and an optical fiber communication system incorporating such an optical waveguide fiber is also disclosed.

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Ithaca, NY, United States of America

V Srikant