Ofs Fitel, LLC

Fitel USA Corporation

Lucent Technologies Inc.

Other

University of Rochester

Agere Systems Guardian Corp.

Furukawa Electric North America, Inc.

Paul S Westbrook

Benjamin John Eggleton

Tristan Kremp

Kenneth Stephen Feder

Jeffrey W Nicholson

Thomas Andrew Strasser

David John DiGiovanni

Tommy Geisler

Kazi S Abedin

Vitaly Mikhailov

Eric A Swanson

John A Rogers

Turan Erdogan

Arturo Hale

Yaowen Li

William R Holland

Gregory M Bubel

Daniel Mahgerefteh

Man Fei Yan

Stefan Hunsche

Siddharth Ramachandran

Paul Francis Wysocki

Rolando Patricio Espindola

Robert Scott Windeler

Benyuan Zhu

David J Kudelko

Mikhail Sumetsky

Thomas G Brown

Gregory Raybon

Jon W Engelberth

Herbert Haunstein

Steven Herbert Simon

Jerome C Porque

Paul Steinvurzel

Glen Robert Kowach

Pierre Wiltzius

Carl Edmund Soccolich

Peter Mach

Lothar Benedict Moeller

Matthias Berger

Raja A Ahmad

Rajan D Deshmukh

Sharad Ramanathan

Ashish Ahuja

Tsing Hua Her

Michael Sumetsky

Pavel Ivanoff Reyes

Geoffrey L Burdge

Wing Ko

David J Digiovanni

Yufeng Li

Misha Sumetsky

Andreas Munk

A high backscattering optical fiber comprising a perturbed segment in which the perturbed segment reflects a relative power such that the optical fiber has an effective index of n, a numerical aperture of NA, a scatter of Rthat varies axially along the optical fiber, a total transmission loss of α, an in-band range greater than one nanometer (1 nm), and a figure of merit (FOM) in the in-band range. The FOM being defined as:

High backscattering waveguides

An extended length of optical fiber having an offset core with an inscribed Bragg grating is used a distributed sensor in combination with an optical frequency domain reflectometer (OFDR) to enable measurement small-scale (e.g., sub-millimeter) contortions and forces as applied to the fiber. The offset core may be disposed in a spiral configuration around the central axis of the optical fiber to improve the spatial resolution of the measurement. A reference surface exhibit a predetermined texture (in the form of a series of corrugations, for example, that may be periodic or aperiodic, as long as known a priori) is disposed adjacent to a longitudinal portion of the sensor fiber. The application of a force to the combination of the plate and the fiber creates a local strain in the grating formed along the offset core of the fiber that results in a shift in the Bragg wavelength of the grating. Using ODFR measurement techniques, an analysis of the Bragg wavelength shift allows for a high resolution force measurement to be obtained.

High resolution distributed sensor utilizing offset core optical fiber

A high backscattering optical fiber comprising a perturbed segment in which the perturbed segment reflects a relative power such that the optical fiber has an effective index of n, a numerical aperture of NA, a scatter of Rthat varies axially along the optical fiber, a total transmission loss of &#x3b1;, an in-band range greater than one nanometer (1 nm), and a figure of merit (FOM) in the in-band range. The FOM being defined as: 

An optical probe includes an optical source that generates an optical beam that propagates from a proximal end to a distal end of an optical fiber that imparts a transformation of a spatial profile of the optical beam. An optical control device imparts a compensating spatial profile on the optical beam that at least partially compensates for the transformation of the spatial profile of the optical beam imparted by the optical fiber in response to a control signal from a signal processor. A distal optical source generates a calibration light that propagates through the one or more optical waveguides from the distal end to the proximal end of the optical fiber. An optical detector detects the calibration light and generates electrical signals in response to the detected calibration light. The signal processor generates the control signal to instruct the optical control device to impart the compensating spatial profile on the optical beam that at least partially compensates for the transformation of the spatial profile of the optical beam imparted by the optical fiber.

Optical probe

A high backscattering optical fiber comprising a perturbed segment in which the perturbed segment reflects a relative power such that the optical fiber has an effective index of n, a numerical aperture of NA, a scatter of R, a total transmission loss of &#x3b1;, an in-band range greater than one nanometer (1 nm), a center wavelength (&#x3bb;) of the in-band range (wherein 950 nm&#x3c;&#x3bb;&#x3c;1700 nm), and a figure of merit (FOM) in the in-band range. The FOM&#x3e;1, with the FOM being defined as: 

Disclosed herein is an optical fiber having an optically uniform coating having no physical defects in the coating greater than 100 micrometers in size over a length of 50 meters or greater.

Optically uniform fiber, methods of making, and methods of inspecting

Optical probe using multimode optical waveguide and proximal processing

An optical fiber having at least one fiduciary mark is provided. The at least one fiduciary mark is located at one or more axial positions along the optical fiber. The at least one fiduciary mark is configured to produce at least one change in a backscattering signal in the optical fiber. The at least one change in a backscattering signal may be an abrupt change in the backscattering signal. The abrupt change in the backscattering signal occurs over a length of the optical fiber that is of the order of or less than a spatial resolution of an interrogation system employed to detect the backscattering signal.

Optical sensor having fiduciary marks detected by backscattered light

An arrangement and method that compensates for variation in grating strength associated with forming multiple gratings in multicore fiber is proposed where the writing efficiency of the beam(s) used to form the gratings is controlled to compensate for fiber lensing effects. In one case, a spacing between the multicore optical fiber and the beam source is controlled such that the writing efficiency (which decreases as a function of the space between the source and the fiber) compensates (at least in part) for the increased beam intensity attributed to the lensing effect of the fiber itself. The width of beam itself may also be controlled to modify the writing efficiency.

Compensation of fiber lensing effect during grating fabrication in multicore fiber

A high backscattering fiber comprising a perturbed segment in which the perturbed segment reflects a relative power that is more than three (3) decibels (dB) above Rayleigh scattering. The high backscattering fiber also exhibits a coupling loss of less than 0.5 dB.

A method of, and apparatus for, inscribing a grating in an optical waveguide so as to reduce transverse inscription variations, are provided. The waveguide is exposed to multiple beams or interference patterns of actinic radiation from multiple azimuthal directions. The beams of actinic radiation are preferably split into a plurality of beams that have wave vectors with different longitudinal components, e.g., via gratings such as phase masks. The periods and phases of the interference patterns of the beams of actinic radiation are preferably matched. A control beam may be provided that does not hit the waveguide. A control loop optionally controls at least one of the position or orientation of at least one of the beams of actinic radiation. The gratings are, for example, Bragg gratings.

Method of and apparartus for inscription of fiber gratings from multiple azimuthal angles and fiber so inscribed

Methods and systems using one or more distributed feedback (DFB) lasers for capturing changes in the lasing environment are disclosed. Specifically, a sensor for measuring a measurand, such as pressure or temperature, or changes in a measurand, includes a fiber with at least one core, at least one fiber laser cavity formed by a single fiber grating in the core, wherein the laser operates on at least two modes along at least part of its length. The DFB laser includes a section that is bent into a non-linear shape and at least one pump laser connected to the fiber laser cavity. When the DFB laser experiences a perturbation or measurand change that changes the spacing of the modes, a change in an RF beat note is generated. This beat note can then be measured and related to the measurand change.

DBF fiber laser bend sensor and optical heterodyne microphone

The disclosed embodiments provide systems and methods for mitigating lensing and scattering as an optical fiber is being inscribed with a grating. The disclosed systems and methods mitigate the lensing phenomenon by surrounding an optical fiber with an index-matching material that is held in a vessel with an integrated interferometer (e.g., phase mask, etc.). The index-matching material has a refractive index that is sufficient to reduce intensity variations of the actinic radiation within the optical fiber. Some embodiments of the system include different vessels for holding the index-matching material, with the vessel having an interferometer integrated into the vessel. These vessels permit the optical fiber to be surrounded by the index-matching material while the gratings are written to the optical fiber.

Index matched grating inscription

The disclosed embodiments provide systems and methods for mitigating lensing and scattering as an optical fiber is being inscribed with a grating. The disclosed systems and methods mitigate the lensing phenomenon by surrounding an optical fiber with an index-matching material that is held in a vessel with a sealed phase mask. The sealed phase mask allows it to be in contact with a liquid index-matching material without having the liquid index-matching material seep into the grooves of the sealed phase mask. Thus, for some embodiments, the sealed phase mask may be immersed in a liquid index-matching material without adversely affecting the function of the phase mask.

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Bridgewater, NJ, United States of America

Paul S Westbrook