United Technologies Corporation

Other

Halliburton Energy Services, Inc.

Deutschetelekom Ag

Her Majesty the Queen in Right of Canada, As Represented by the Minister

Finmeccanica S.p.a. - Ramo Aziendale Alenia

Oft Associates Llp

Gerald Meltz

Elias Snitzer

William H Glenn

James R Dunphy

Gary A Ball

William W Morey

Hans Wilfried Koops

Leon A Newman

Kenneth O Hill

Pietro Ferraro

Mauro Varasi

Antonello Vannucci

Mario Signorazzi

Claudio Voto

Neal Gregory Skinner

Wolfgang Dultz

Thomas W Grudkowski

Frederick J Leonberger

Derwyn C Johnson

Carl M Ferrar

Peter K Cheo

Donald E Cullen

Erna Frins

Richard R Grzybowski

Martin C Foster

Louis B Allen, Jr

Arnold L Wilson

Sabato I Imparato

Francis X D'Amato, Deceased

Sabato Inserra Imparato

A distributed flow properties wellbore measurement system. In a described embodiment, a system for determining at least one parameter of a fluid in a tubular string includes a pressure pulse generator attached to the tubular string and a set of sensors. The generator transmits a pressure pulse through the fluid. The set of sensors is used to determine a velocity of the pressure pulse transmitted through the fluid, and to determine a velocity of the pressure pulse reflected back through the fluid.

Distributed flow properties wellbore measurement system

A method of trimming fused-tapered couplers, with or without in-fiber Bragg gratings, to form multiplexers, demultiplexers or combinations of both, by either or both of (1) increasing the phase differential between the symmetric and asymmetric supermodes by irradiating one or both ends of the coupler with UV radiation confined transversely to between the cores of the fibers, and (2) decreasing the phase differential between the modes by irradiating a portion of one or both ends of the coupler with two beams of UV radiation, each confined transversely to include a corresponding core and excluding a significant fraction of the space between the cores.

UV-trimmed fused tapered couplers

An polarization compensator is disclosed for passing light in a predetermined wavelength range. The compensator has unequal output orthogonal polarizations for light launched into the device within a specific wavelength range. A waveguide having a blazed grating having a blaze angle &thgr; of between 20&deg; and 45&deg; with respect to the optical axis of the waveguide exhibits a tap efficiency difference for orthogonal polarizations for offsetting and lessening a polarization dependence of the device. This waveguide is optically coupled with the optical device requiring polarization compensation. The grating is oriented about its optical axis to lessen the inequality in output orthogonal polarizations for light launched into the optical device.

Method and device for reducing polarization dependence in an optical component or optical system

A telecommunication system having frequency-dividing optical components where light pulses having different frequencies are coupled out of a optical fiber by fiber grating and/or photonic crystals and imaged by focusing elements outside of the optical fiber. The fiber grating for different frequencies can be used in a single period or in different periods disposed one after the other. The photonic crystals can be used at the optical fiber extremity or etched in a channel or trench in a glass fiber. Delay elements are added to ensure that different frequency light pulses are imaged simultaneously in a given and desired time relation as required for further parallel processing.

Telecommunication system having frequency-dividing optical components for the parallel processing of optical pulses

One or more photonic crystals 11, 22, 40, 58, 59 are formed directly in the path of light within an optical fiber 13, 23, 42, 56. Light processed by the photonic crystal may be transmitted out of the fiber by means of a lens 48 or it may be measured by a photoresistive device 51, 60. The photonic crystal may be formed in a trench 12 as an array of dielectric rods 16 having one or more selective defects 17, or the crystal may be formed by providing holes 20 directly in the optical fiber. Filling the interstices between rods 16 with non-linear optical material, and subjecting the crystal to a varying electric field applied by electrodes or to a varying optical radiation can produce a tunable photonic crystal within an optical fiber.

In-fiber photonic crystals and systems

A microlens 30 is formed on the outer surface of an optical fiber 20 having an in-fiber Bragg grating 24 (FBG) formed in the core 21, 36 thereof, to focus light diffracted by the FBG onto other fibers or optical devices, or to focus light received at the fiber onto the FBG. Various single- and multi-microlens configurations of one or more fibers perform a variety of functions such as signal coupling, multiplexing, signal splitting, spectrography, tapped delay, timed-delay phase adjusting, circulating storage, and so forth. The microlenses may employ angle-increasing prisms and may comprise Fresnel lenses.

Fiber-integrated microlenses and optical fiber FBG couplers,

A machine having protruding elements 26 and an adjacent abradable seal 18, which move relative to each other, an air-path clearance G between the seal 18 and the elements 26 and an element distance D2 between the sensor 10 and the elements 26, is provided with a sensor 10 which is recessed within the seal 18 by a recess distance D. A clearance/thickness circuit 14 provides transmitted and reflected microwave signals 30,32 along a coaxial cable 12 having a characteristic impedance, to the sensor 10, which has an impedance substantially matched to the characteristic impedance of the cable 12. The sensor 10 provides the reflected signal 32 which is indicative of the recess distance D when the elements 26 are not in front of the sensor 10 and is indicative of the blade distance D2 between the sensor 10 and the elements 26 when the elements 26 are in front of the sensor 10. The circuit 14 receives the reflected signal 32 and provides electrical signals indicative of the recess distance D and/or the air-path clearance G. Alternatively, the circuit 14 may provide only the recess distance D. The sensor 10 provides such measurements whether or not the machine is operating.

Microwave recess distance and air-path clearance sensor

A birefringent active fiber laser sensor includes one or more fiber lasers 12, 14, 16, each having a pair of Bragg gratings 18, 20, embedded in a fiber 10 and excited by a common pump light 30. At least one of the lasers 12, 14, 16 has a laser cavity wit a predetermined birefrigence and a lasing light at a first lasing frequency along a first polarization axis, and at a second fusing frequency along a second polarization axis. A difference frequency between the first and the second lasing frequencies is related to the magnitude of the birefringence, and the birefringence varies in response to a perturbation. Output light 104 from each of the lasers 12,14,16 is fed to a defraction grating 106 which splits the beam 104 into different wavelength groups, each group having the two lasing frequencies and polarizations of a given laser. Each wavelength group is fed to a corresponding analyzer 122-126 which combines the first and second frequencies and polarizations for each laser to form a lower difference or 'beat' frequency, thereby allowing lower frequency detection devices 138-142 to be used.

Birefringent active fiber laser sensor

A single polarization fiber and/or amplifier includes a non-polarization preserving fiber 10 having a fiber grating tap 12 which has a predetermined length and strength (.DELTA.n/n) and is oriented at a predetermined angle .theta. and has a grating spacing D so as to couple-out of the fiber 10 a predetermined amount of one polarization 24 over a predetermined wavelength range of an input light 16 and pass the other polarization 28 as output light 26, the grating length being substantially the length of the fiber 10. Alternatively, all or a portion of the fiber 10 may be doped to form a polarization sensitive optical amplifier.

Single polarization fiber and amplifier

A remote active multipoint fiber laser sensor includes a plurality of fiber lasers 12,14,16, each having a pair of Bragg gratings 18,20, embedded in a fiber 10 and excited by a common pump light 30. The lasers 12,14,16 lase at different longitudinal modes (lasing wavelengths) and emit light 32,34,36, at their respective wavelengths .lambda.1,.lambda.2,.lambda.n. The lasing wavelength of each laser shifts due to perturbations, such as strain or temperature, applied thereto. The output light 32,34,36 is fed to a spectrum analyzer 50 where the wavelength shift is analyzed. A signal processor 54 reads the wavelength shift and provides a signal on lines 56 indicative of the perturbation at each of the lasers/sensors 12-16. Alternatively, a single laser may be used as a single sensor. Alternatively, birefringent fiber may be used as the fiber cavities 21 and the two polarizations are beat together to form a lower difference or 'beat' frequency, thereby allowing lower frequency detection devices to be used.

Active multipoint fiber laser sensor

A polarized fiber laser source includes a fiber laser 10 comprising a pair of Bragg gratings 14,16 at opposite ends of a fiber laser cavity 18 which is doped with a rare-earth dopant so as to allow lasing to occur at a lasing wavelength .lambda..sub.L. A grating tap 26 is provided along a portion of the laser cavity 18 to couple-out a predetermined amount of light along one polarization, e.g., the 's' polarization', at the lasing wavelength .lambda..sub.L. This causes one polarization mode to experience more loss than the other, thereby allowing the fiber laser to lase only on the less lossy polarization mode and causing the laser output light 40 to be polarized only along such polarization.

Polarized fiber laser source

A system based on integrated optical technologies for the measurement and diagnostics of physical parameters on whatever structure, by the use of optical sensors, made by the fiber embedded Bragg grating method and by the use of a planar integrated optics device for the analysis of the optical signal. The sensors may be embedded or bonded to the structure, allowing the measurement of parameters like strain and temperature, in either a static or dynamic regime. The system pertains to the technical field of the diagnostics and measurements of mechanical or thermal parameters and to the application field of ground, water and aerospace transportation and also to the application field of construction.

Integrated optical instrumentation for the diagnostics of parts by

An embedded optical sensor has a plurality of layers 10-20 and an optical fiber 21 with a fiber grating 28, disposed between the layers 14,16. The layers 10-20 comprise filaments 22 and resin 24 which have different thermal expansion coefficients and the filaments 22 are oriented so as to create unequal transverse residual stresses that act through the geometry of a resin-rich region that surrounds on the grating 28 in the fiber 21. The unequal transverse residual stresses cause birefringence in the grating 28, thereby causing the grating 28 to reflect light 32 having two wavelengths with a predetermined separation, each along a different polarization axis. The wavelength separation and average wavelength between such separation have different sensitivities to temperature and strain, thereby allowing independent temperature and strain measurements using only a single grating. The birefringence is maximized when the filaments 22 of the adjacent layers 10,12 are oriented at 90 degrees with respect to the longitudinal (Z-axis) of the fiber 21.

Embedded optical sensor capable of strain and temperature measurement

An optical waveguide light redirecting arrangement includes an optical waveguide having a solid portion that guides light in a first path along a longitudinal axis, with at least one grating region being embedded in the solid portion at a location remote from its end portions. The grating region includes a multitude of grating elements extending at such longitudinal spacings and at such oblique angles relative to the longitudinal axis to redirect light reaching the grating elements between the first path and at least one second path extending externally of the waveguide and diverging between a focus situated at a predetermined distance from the waveguide and the grating region. When light is directed in one of the first and second paths toward the grating region, it is redirected by the grating elements into the respectively other of the second and first paths with attendant in-phase combination in the other path of light having a wavelength within a range around a central wavelength. The grating elements are formed in the waveguide by exposing the waveguide to an interference pattern of two ultraviolet radiation beams that are symmetrical with respect to a plane extending at the oblique angle relative to the waveguide axis at the center of the grating region.

Optical waveguide embedded light redirecting and focusing Bragg grating

An optical waveguide mode discrimination light filtering arrangement inclues an optical waveguide having an elongated multimode core, and a cladding that guides at least two modes of light of a given frequency in an elongated path along a longitudinal axis of said core. At least one grating region is embedded in the core at a location remote from the end portions of the core and has a multitude of grating elements extending with a substantially equal longitudinal spacing substantially normal to the longitudinal axis to reflect light propagating in the path and reaching the grating elements back into the path for longitudinal propagation therein opposite to the original propagation direction. The spacing of the grating elements is so related to the axial wavelength of one of the modes that the reflected light of the one mode interferes constructively while the light of any other of the modes passes through the grating region in the original propagation direction substantially without attenuation.

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Avon, CT, United States of America

Gerald Meltz