Lucent Technologies Inc.

At&t Bell Laboratories

At+t Corp.

Ofs Fitel, LLC

Fitel USA Corporation

Cfs Fitel, LLC

Daryl Inniss

David John DiGiovanni

Ashish Madhukar Vengsarkar

Qian Zhong

Stephen G Grubb

Kenneth L Walker

Valerie Jeanne Kuck

Tristan Kremp

Vitaly Mikhailov

Ralph Stephen Jameson

Brian Mangan

John E Pacini

Darryl L Brownlow

Jefferson L Wagener

Howard Edan Katz

Charles H Henry

James R Petisce

Carl Raymond Taylor

Rolando Patricio Espindola

Lee L Blyler

Mark Anthony Paczkowski

Lloyd Shepherd

Marcia Lea Schilling

Debra A Simoff

Edward J Laskowski

Sandra Greenberg Kosinski

Michele A Milbrodt

Charles R Kurkjian

Jennifer Aspell

Maureen Gillen Chan

Michael J Matthewson

A hollow core optical fiber and cable combination is configured to exhibit minimal SNR and loss degradation. This is achieved by either: (1) reducing the coupling between the fundamental and other (unwanted) modes propagating within the hollow core fiber; or (2) increasing the propagation loss along the alternative. The first approach may be achieved by designing the cable to minimize perturbations and/or designing the hollow core fiber to fully separate the fundamental mode from the unwanted modes so as to reduce coupling into the unwanted modes. Whether through fiber design or cable design, the amount of light coupled into unwanted modes is reduced to acceptable levels. The second approach may be realized through either fiber design and/or cable design to suppress the light in unwanted modes so that an acceptably low level of light is coupled back into the fundamental mode.

Cabling configurations for hollow core optical fibers

A hollow core optical fiber and cable combination is configured to exhibit minimal SNR and loss degradation. This is achieved by either: (1) reducing the coupling between the fundamental and other (unwanted) modes propagating within the hollow core fiber, or (2) increasing the propagation loss along the alternative. The first approach may be achieved by designing the cable to minimize perturbations and/or designing the hollow core fiber to fully separate the fundamental mode from the unwanted modes so as to reduce coupling into the unwanted modes. Whether through fiber design or cable design, the amount of light coupled into unwanted modes is reduced to acceptable levels. The second approach may be realized through either fiber design and/or cable design to suppress the light in unwanted modes so that an acceptably low level of light is coupled back into the fundamental mode.

The disclosed fiber Raman device comprises means for coupling pump radiation of a first wavelength &lgr; and a second wavelength &lgr; into a length of silica-based fiber, with &lgr; being different from &lgr; , and with both of &lgr; and &lgr; being less than an output radiation &lgr; of the fiber Raman device. The Raman device further comprises at least a first and a second wavelength-selective element disposed to provide one or more optical cavities for Raman shifting of light in the fiber. At least one of the optical cavities is selected such that at least one of &lgr; and &lgr; is off resonance. Exemplarily, the Raman device is a topologically linear or circular Raman laser or amplifier, and the wavelength selective element is a fiber Bragg grating or a WDM. The Raman device is advantageously used in an optical fiber communication system.

Article comprising a fiber raman device

Laser apparatus for delivering optical power to an output port comprises first and second fiber lasers having at least partially overlapping cavity resonators. In one state the lasers are phase locked; in another they are not. An intracavity polarization transformer (e.g., a polarization modulator or a segment of PMF) determines the phase state of the apparatus. In each state the reflectivity of a reflector common to the lasers determines the amount of optical power which is delivered to the output port. In one embodiment the apparatus has a plurality of output ports to which separate utilization devices are coupled. The phase state of the lasers and the reflectivity of the common reflector determines how the optical power is allocated among the devices.

Internally modulated coupled cavity fiber lasers

An optical fiber amplifier is pumped by a pair of pump lasers which have at least partially overlapping resonators. In one embodiment, the fiber gain section of the amplifier is located external to the resonators. In another embodiment, the coupler, which couples the pump lasers to the gain section, is located at least partially within said resonators. In a preferred embodiment the resonators are provided with polarization selection properties, and the outputs of the pump lasers are coherent.

Multiple fiber laser pump sources

An optical fiber amplifier is pumped by a fiber pump laser which has a pair of separate active media within a common resonator. The fiber gain section of the amplifier is also located within the resonator.

Fiber amplifier with multiple pass pumping

An optical fiber protected from degradation caused by corrosion from environmental fluids. The optical fiber includes a core-cladding assembly surrounded with a thin quasi metal oxide film (preferably .about.10 nm in depth). Over time, particularly under the influence of the elevated temperatures, the initially deposited reagents of the thin film oxidize or hydrolyze, removing the organic components, and bonding a quasi metal oxide film on the surface of the cladding. The resulting film significantly retards corrosion by blocking the environmental fluids from reacting with flaws in the cladding surface of the fiber, thus improving the mechanical performance and reliability of the optical fiber. In addition, the thin film protects the fiber against incidental abrasions. Alternatively, the quasi metal oxide reagents are deposited into a protective polymer layer of the fiber or a filling compound of a fiber cable, rather than directly onto the cladding surface, whereby the same protective effect is achieved when the reagents diffuse through the polymer layer or filling compound to the core-cladding surface.

Corrosion-resistant optical fibers and waveguides

In accordance with the invention, arrays optical sources are combined in a multilevel planar optical waveguide structure for insertion into an optical fiber laser. The basic element of the combiner is a planar array of multiple waveguides which converge and are gradually tapered to a single output waveguide. A plurality of such elements integrally formed on successive cladding layers provides a high power stack of vertically aligned outputs. An arrangement is described for using such apparatus in the amplification of optical communications signals.

Apparatus for pumping an optical fiber laser

In an optical fiber light source a section of multimode fiber is interposed between an energizing laser (e.g,, a diode laser) and a single mode fiber active medium. In a preferred embodiment the single mode fiber active medium is surrounded by a multimode cladding coupled to the multimode fiber. The source may serve as a pump laser for a fiber amplifier or as an amplified spontaneous emission source. Arrangements for coupling several energizing lasers to the active medium are also described.

Fiber light source with multimode fiber coupler

Recognizing the rate-determining nature of the coating removal and recoating steps, applicants have demonstrated that with proper combination of low absorbing polymer, glass and low intensity radiation, UV-induced gratings can be side-written into polymer coated fibers without removing the polymer, thus permitting up the possibility of high speed fabrication of fiber gratings.

Formation of gratings in polymer-coated optical fibers

A method of controlling the polarization properties of a photo-induced device in an optical waveguide and a method of investigating the structure of a light guiding body such as an optical waveguide are disclosed. A device, such as gratings, is written by exposing one side of the optical waveguide to light. The unexposed side is then exposed to an amount of light sufficient to impart the desired birefringence to the written device. The birefringence can be minimized in the written device by exposing the opposite side to light in an amount sufficient to minimize the amount of birefringence. The light guiding body is investigated by cleaving the elongated light guiding body, such as an optical waveguide, to expose its cross-section. The cleaved section is then treated to expose difference between the core and cladding. Treatment may include etching in an acid or base. The cross-section is then profiled with a scanning probe microscope such as an atomic force microscope to investigate the structure of the light guiding body. The difference in refractive index can be determined across the cleaved endface based on differences in the etched depth.

Method of controlling polarization properties of a photo-induced device

A method of controlling the polarization properties of a photo-induced device in an optical waveguide and a method of investigating the structure of a light guiding body such as an optical waveguide are disclosed. A device, such as gratings, is written by exposing one side of the optical waveguide to light. The unexposed side is then exposed to an amount of light sufficient to impart the desired birefringence to the written devices. The birefringence can be minimized in the written device by exposing the opposite side to light in an amount sufficient to minimize the amount of birefringence. The light guiding body is investigated by cleaving the elongated light guiding body, such as an optical waveguide, to expose its cross-section. The cleaved section is then treated to expose difference between the core and cladding. Treatment may include etching in an acid or base. The cross-section is then profiled with a scanning probe microscope such as an atomic force microscope to investigate the structure of the light guiding body. The difference in refractive index can be determined across the cleaved endface based on differences in the etched depth.

Method of determining changes in the refractive index of an optical

Method of determining and investigating the physical structure of a

Method of forming photo-induced device and product

Optical fiber and cable performance are assured by a category of UV-cured polyurethane acrylates. Low cost is the consequence of use of the polycarbonate oligomer. Good performance and long life are ascribed to other ingredients of the coatings. Dependence on the hindered phenols for antioxidant protection assures sufficient protection for these inherently stable materials without incurring fiber damage found to result from use of hindered amine antioxidants.

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Hillsborough, NJ, United States of America

Daryl Inniss