Lucent Technologies Inc.

Fitel USA Corporation

Furukawa Electric North America, Inc.

Fitel Ush Corp.

Ofs Fitel, LLC

David Kalish

Thomas John Miller

Robert Lingle, Jr

Jinkee Kim

Albert John Ritger

Kai H Chang

Carl Raymond Taylor

John Michael Turnipseed

Siu-Ping Hong

Paul Francis Glodis

Paul Emilien Neveux, Jr

Raymond Bradfield Kummer

Yifei Qian

Kenneth L Walker

Andrew Roman Chraplyvy

James William Fleming

William Alfred Reed

Ian A White

David W Peckham

Steven Alan Jacobs

Yi Sun

Bernard Raymond Eichenbaum

Zhi Zhou

Arthur F Judy

Donald Jablonowski

Donald Paul Jablonowski

David Wayne Peckham

Michael L Pearsall

Janice Bilecky Haber

Shunhe Xiong

Gary Patrick Emery

Charles Francis Gridley

Methods for modifying preform core ovality during and subsequent to the formation of an optical fiber preform. After MCVD deposition forms the core rod, but prior to overcladding of the core rod, the code rod may be etched to change its ovality. In order to etch the core rod, the core rod may be mounted to lathe, rotated by at least two rotors, and subjected to a heat source. Additionally, one of the at least two rotors may be phase-shifted from another one of the at least two rotors after the core rod is mounted on the lathe.

Methods for modifying ovality of optical fiber preforms

Embodiments of the invention include a method for making optical fiber having reduced aging or hydrogen aging loss over the life of the fiber and optical fiber systems including such optical fibers. Improved silicon-oxygen stoichiometry during one or more preform manufacturing steps reduces the amount of Si defects generated in the optical fiber preform. Also, deuterium exposure of optical fiber drawn from the preform reduces the likelihood of having atomic defects such as Si defects in the optical fiber that, over time, attract and bond with hydrogen atoms to form molecules that contribute to increased water absorption loss. The inventive method produces optical fibers with improved transmission characteristics, e.g., optical fibers made by methods according to embodiments of the invention have transmission loss at 1385 nanometers that is less than 0.33 dB/km and the aging loss increase thereafter is less than 0.04 dB/km.

Method for fabricating optical fiber using deuterium exposure

An expeditious method for introducing geometric perturbations into lightguide during fabrication offers a perturbation stream of amplitude and periodicity&#x2014;constant or varying&#x2014;to satisfy a variety of needs.

Optical fiber fabrication and product

An improved optical fiber design has been found to exhibit a relatively low attenuation at the wavelength of 1385 nm (the 'water peak'), allowing for Raman amplification to be efficient and effective at wavelengths in the S-band range of 1460 to 1530 nm. An ultra-dry process is used to mate an inner core rod (core plus surrounding trench) with a cladding tube (ring region plus cladding layers) and provide a water peak loss on the order of 0.325 dB/km. The low water peak is combined with appropriate dispersion values and zero dispersion wavelength to form a fiber that supports transmission and Raman amplification in the S-, C- and L-bands of interest for optical transmission systems.

Optical fiber for improved performance in S-, C- and L-bands

An inverse dispersion fiber having a large effective area and a transmission system that incorporates the fiber for providing dispersion and dispersion slope compensation in a transmission fiber. The large-effective-area inverse dispersion optical fiber (IDF) has a negative dispersion and a negative dispersion slope. The effective area, A, of the IDF preferably is greater than approximately 31 micrometers squared (&#x3bc;m) at a transmission wavelength of approximately 1550 nm. The large-effective-area IDF is suitable for use with super-large-effective-area (SLA) transmission fiber for compensating dispersion in the SLA transmission fiber while reducing nonlinear effects between wavelength channels and cabling loss, which is especially advantageous in transoceanic and long-haul terrestrial systems. These nonlinear effects are inversely related to the effective area of the fiber (i.e., nonlinearities&#x2dc;1/A). Thus, an increase in the effective area of the fiber translates into a decrease in nonlinear interactions, which increases bandwidth capabilities and limits signal degradation. Furthermore, the large-effective-area IDF of the present invention has very desirable transmission properties. The present invention also provides a transmission system comprising at least one of the large-effective-area IDF optical fibers of the present invention. Furthermore, Acan be made large without having to increase the ratio, R, of the diameter of the core to the diameter of the trench region.

Large-effective-area inverse dispersion compensating fiber, and a transmission line incorporating the same

The specification describes an improved optical fiber design in which the criteria for high performance in a Raman amplified optical system, such as moderate effective area, moderate dispersion, low dispersion slope, and selected zero dispersion wavelength, are simultaneously optimized. In preferred embodiments of the invention, the dispersion characteristics are deliberately made selectively dependent on the core radius. This allows manufacturing variability in the dispersion properties, introduced in the core-making process, to be mitigated during subsequent processing steps.

Method for the manufacture of optical fibers, improved optical fibers, and improved raman fiber amplifier communication systems

Method for the manufacture of optical fibers, improved optical fibers, and improved Raman fiber amplifier communication systems

Embodiments of the invention include a method for making optical fiber having reduced aging or hydrogen aging loss over the life of the fiber and optical fiber systems including such optical fibers. The method includes the steps of dehydrating an optical fiber glass core rod in a first environment including oxygen and at least one of chlorine-containing gases, fluorine-containing gases and carbon monoxide; and adjusting the oxygen stoichiometry of the first environment so that it is neither oxygen-rich nor oxygen-deficient. Improved silicon-oxygen stoichiometry during one or more preform manufacturing steps reduces the amount of Si defects generated in the optical fiber preform. Also, deuterium exposure of optical fiber drawn from the preform reduces the likelihood of having atomic defects such as Si defects in the optical fiber that, over time, attract and bond with hydrogen atoms to form molecules that contribute to increased water absorption loss. The inventive method produces optical fibers with improved transmission characteristics, e.g., optical fibers made by methods according to embodiments of the invention have transmission loss at 1385 nanometers that is less than 0.33 dB/km and the aging loss increase thereafter is less than 0.04 dB/km.

Method of making an optical fiber using preform dehydration in an environment of chlorine-containing gas, fluorine-containing gases and carbon monoxide

Embodiments of the invention include an optical energy transmission system, method and apparatus having improved mode coupling. According to embodiments of the invention, an optical energy transmission medium such as an optical fiber includes a plurality of particles formed in one or more coating region layers surrounding the cladding region and/or one or more buffer region layers surrounding the coating region for inducing microbending thereof, thus promoting advantageous mode coupling, which improves bandwidth potential by reducing dispersion. The method for manufacturing the inventive optical energy transmission medium includes forming one or more coating region layers and/or one or more buffer region layers containing particles such as fumed silica in such a way that particles are maintained within the optical energy transmission medium and form controlled perturbations along the optical fiber that enhance mode coupling to the extent that bandwidth of the optical fiber is improved.

Mode coupling buffered optical fiber apparatus and method for making

Embodiments of the invention include an optical energy transmission system, method and apparatus having improved mode coupling. According to embodiments of the invention, an optical energy transmission medium such as an optical fiber includes bubbles formed therein for inducing microbending of the optical energy transmission medium, thus promoting advantageous mode coupling, which improves bandwidth potential by reducing dispersion. The bubbles are formed, e.g., in one or more buffer region layers and/or at the interface between the coating and buffer regions. The method for manufacturing the inventive optical energy transmission medium includes controllably forming one or more buffer region layers around the coated optical fiber or other transmission medium in such a way that that a desired amount of bubbles is created and maintained within one or more of the buffer region layers and/or at the interface between the coating and buffer regions. The bubbles form controlled perturbations that enhance mode coupling to the extent that bandwidth of the optical fiber is improved. The quantity and size of the bubbles formed in the optical energy transmission medium are controlled by, e.g., the amount of moisture present in the applied coating.

Mode mixing buffered optical fiber apparatus and method for making

A high-capacity optical fiber network &lsqb;,&rsqb; includes wavelength-division multiplexing (WDM) within the 1.4 micron (&mgr;m) wavelength region (i.e., 1335-1435 nm). Such a system includes optical fiber &lsqb;,&rsqb; whose peak loss in the 1.4 &mgr;m region is less than its loss at 1310 nm. The optical fiber has a zero dispersion wavelength (&lgr;,) at about 1310 nm, and linear dispersion between about 1.5 and 8.0 ps/nm-km within the 1.4 &mgr;m region. At least three WDM channels operate at 10 Gb/s in the 1.4 &mgr;m wavelength region and have a channel separation of 100 GHz. In one illustrative embodiment of the invention, a broadcast television channel, having amplitude modulated vestigial sideband modulation, simultaneously operates in the 1.3 &mgr;m region (i.e., 1285-1335 nm) and/or the 1.55 &mgr;m region (i.e., 1500-1600 nm). In another embodiment of the invention, 16 digital data channels are multiplexed together in the 1.55 &mgr;m region, each channel operating at about 2.5 Gb/s. Raman amplifiers &lsqb;,&rsqb; are used for amplification in the 1.3 &mgr;m and the 1.4 &mgr;m wavelength regions, whereas an Erbium amplifier &lsqb;,&rsqb; is used for amplification in the 1.55 &mgr;m wavelength region.

Arrangement of optical fiber segments for minimizing effect of nonlinearities

A singlemode optical fiber 700 having very low loss at 1385 nm, and a practical method for making same are disclosed. A core rod 20 is fabricated using vapor axial deposition to have a deposited cladding/core ratio (D/d) that is less than 7.5. The core rod is dehydrated in a chlorine- or fluorine-containing atmosphere at about 1200.degree. C. to reduce the amount of OH present to less than 0.8 parts per billion by weight, and then consolidated in a helium atmosphere at about 1500.degree. C. to convert the porous soot body into a glass. The consolidated core rod is elongated using an oxygen-hydrogen torch that creates a layer of OH ions on the surface of the rod that are largely removed by plasma etching. Finally, the core rod is installed in a glass tube 40 having a suitably low OH content. Thereafter, the tube is collapsed onto the rod to create a preform 60. Conventional methods are employed for drawing an optical fiber from the preform and applying one or more protective coatings 75, 76. The disclosed method is suitable for commercial production of low-OH fiber. Significantly, the fiber's loss at 1385 nm is reduced to a level that is less than its loss at 1310 nm, thereby rendering the entire wavelength region 1200-1600 nm suitable for optical transmission. In particular, wave-division-multiplex systems are now available to transmit optical signals over distances greater than 10 km in the wavelength region between 1360 nm and 1430 nm.

Method of making a fiber having low loss at 1385 nm by cladding a VAD

A large optical preform 303 is made by a modified chemical vapor deposition (MCVD) process by depositing successive layers of core and cladding materials onto the inside surface of a rotating glass tube 33 having a hydroxyl ion (OH.sup.-) level that is less than 0.5 parts per million (ppm) by weight. The tube is then collapsed inwardly to form a core rod 301 in which the deposited core material 31 has a diameter that is greater than about 5 millimeters and the deposited cladding material 32 has an outside diameter that is less than about 15 millimeters. A machine-vision system 140, 150, 160 monitors and controls the diameter of the glass tube by regulating the pressure within the tube. Moreover, the machine-vision system monitors and controls the straightness of the tube by varying its rotational speed according to angular position. After the core rod 301 is formed, it is plasma etched to remove contaminants, and then overclad with two glass jackets 34, 35 having a hydroxyl ion (OH.sup.-) level that is less than 1.0 ppm by weight to create a large preform 303 from which about 400 kilometers of singlemode optical fiber can be drawn per meter of length.

Method of making a large MCVD single mode fiber preform by varying

Simultaneous dense WDM operation in both the 1310 nm and 1550 nm transparency windows of silica-based optical fiber, is enabled by a fiber design providing for nulled dispersion within a critically positioned wavelength range. Design provides for values of dispersion in both windows sufficiently low for desired per-channel bit rate, and, at the same time, sufficiently high to maintain effects of non-linear dispersion within tolerable limits for WDM operation. Fiber fabrication and system design are described.

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Roswell, GA, United States of America

David Kalish