US20130208283A1 - Variable sensitivity interferometer systems - Google Patents
Variable sensitivity interferometer systems Download PDFInfo
- Publication number
- US20130208283A1 US20130208283A1 US13/879,370 US201113879370A US2013208283A1 US 20130208283 A1 US20130208283 A1 US 20130208283A1 US 201113879370 A US201113879370 A US 201113879370A US 2013208283 A1 US2013208283 A1 US 2013208283A1
- Authority
- US
- United States
- Prior art keywords
- fiber
- optical
- fibers
- signal propagation
- sensor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 230000035945 sensitivity Effects 0.000 title claims abstract description 79
- 230000003287 optical effect Effects 0.000 claims abstract description 101
- 239000000835 fiber Substances 0.000 claims description 109
- 239000013307 optical fiber Substances 0.000 claims description 32
- 230000008878 coupling Effects 0.000 claims description 12
- 238000010168 coupling process Methods 0.000 claims description 12
- 238000005859 coupling reaction Methods 0.000 claims description 12
- 230000004927 fusion Effects 0.000 claims description 3
- 238000000253 optical time-domain reflectometry Methods 0.000 claims description 2
- 230000008901 benefit Effects 0.000 abstract description 3
- 230000004044 response Effects 0.000 description 10
- 238000010276 construction Methods 0.000 description 9
- 239000000463 material Substances 0.000 description 8
- 230000010363 phase shift Effects 0.000 description 6
- 230000010287 polarization Effects 0.000 description 5
- 230000007613 environmental effect Effects 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000012530 fluid Substances 0.000 description 3
- 239000003570 air Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000000977 initiatory effect Effects 0.000 description 2
- 230000001902 propagating effect Effects 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- UKGJZDSUJSPAJL-YPUOHESYSA-N (e)-n-[(1r)-1-[3,5-difluoro-4-(methanesulfonamido)phenyl]ethyl]-3-[2-propyl-6-(trifluoromethyl)pyridin-3-yl]prop-2-enamide Chemical compound CCCC1=NC(C(F)(F)F)=CC=C1\C=C\C(=O)N[C@H](C)C1=CC(F)=C(NS(C)(=O)=O)C(F)=C1 UKGJZDSUJSPAJL-YPUOHESYSA-N 0.000 description 1
- 229920002430 Fibre-reinforced plastic Polymers 0.000 description 1
- 229920000271 Kevlar® Polymers 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000005447 environmental material Substances 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 239000011151 fibre-reinforced plastic Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- -1 for example Substances 0.000 description 1
- 239000004761 kevlar Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02041—Interferometers characterised by particular imaging or detection techniques
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02001—Interferometers characterised by controlling or generating intrinsic radiation properties
- G01B9/02012—Interferometers characterised by controlling or generating intrinsic radiation properties using temporal intensity variation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02015—Interferometers characterised by the beam path configuration
- G01B9/02027—Two or more interferometric channels or interferometers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02049—Interferometers characterised by particular mechanical design details
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02055—Reduction or prevention of errors; Testing; Calibration
- G01B9/02075—Reduction or prevention of errors; Testing; Calibration of particular errors
- G01B9/02078—Caused by ambiguity
- G01B9/02079—Quadrature detection, i.e. detecting relatively phase-shifted signals
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
- G01D5/35325—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using interferometer with two arms in reflection, e.g. Mickelson interferometer
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
- G01D5/35329—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using interferometer with two arms in transmission, e.g. Mach-Zender interferometer
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/8806—Specially adapted optical and illumination features
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/255—Splicing of light guides, e.g. by fusion or bonding
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/36—Mechanical coupling means
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/18—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength
- G08B13/181—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using active radiation detection systems
- G08B13/183—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using active radiation detection systems by interruption of a radiation beam or barrier
- G08B13/186—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using active radiation detection systems by interruption of a radiation beam or barrier using light guides, e.g. optical fibres
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B2290/00—Aspects of interferometers not specifically covered by any group under G01B9/02
- G01B2290/70—Using polarization in the interferometer
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2201/00—Features of devices classified in G01N21/00
- G01N2201/06—Illumination; Optics
- G01N2201/061—Sources
- G01N2201/06113—Coherent sources; lasers
- G01N2201/0612—Laser diodes
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2201/00—Features of devices classified in G01N21/00
- G01N2201/08—Optical fibres; light guides
- G01N2201/088—Using a sensor fibre
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/02—Mechanical actuation
- G08B13/12—Mechanical actuation by the breaking or disturbance of stretched cords or wires
- G08B13/122—Mechanical actuation by the breaking or disturbance of stretched cords or wires for a perimeter fence
- G08B13/124—Mechanical actuation by the breaking or disturbance of stretched cords or wires for a perimeter fence with the breaking or disturbance being optically detected, e.g. optical fibers in the perimeter fence
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49826—Assembling or joining
Definitions
- interferometer systems and more particularly, but not exclusively, to fiber-optic interferometer systems having variable-sensitivity sensors.
- Some innovative interferometer systems are configured to detect and/or locate disturbances (e.g., a disturbance to a secure perimeter, such as a “tap” on a fence, a leak from a pipeline, a change in structural integrity of a bridge, a disturbance to a communication line, a change in operation of a conveyor belt, an impact on a surface or acoustical noise, among others).
- disturbances e.g., a disturbance to a secure perimeter, such as a “tap” on a fence, a leak from a pipeline, a change in structural integrity of a bridge, a disturbance to a communication line, a change in operation of a conveyor belt, an impact on a surface or acoustical noise, among others.
- such systems can be configured to detect and/or locate over distances up to, for example, about 65 kilometers (km) with one passive sensor, and up to,
- optical conduits e.g., optical fibers
- optical conduits have substantially uniform (e.g., unvarying) properties along their lengths, making such optical conduits suitable for a wide variety of applications (e.g., communications, interferometers) that demand homogeneous properties.
- This homogeneity is a result of, among many factors, modern high-quality manufacturing processes for optical fibers, coatings on the optical fibers and various protective sheaths of the cable in which the fibers are typically encased.
- Such longitudinally homogeneous optical conduits typically respond to a given perturbation in a uniform manner, regardless of where the perturbation is applied along the sensor's length.
- a portion of a sensor can be positioned, for example, under water, another portion can be positioned underground and yet another portion can be positioned above-ground (e.g., exposed to the atmosphere).
- known sensors can respond to a given disturbance differently depending, for example, on the environment and which portion of the sensor is perturbed. Therefore, with known sensors having homogeneous sensitivity, it can be difficult to discern one or more characteristics (e.g., amplitude, position, etc.) of any particular disturbance, particularly if the environmental surroundings vary along the sensor's length. Accordingly, known fiber-optic sensors can be prone to initiating “false” or “nuisance” alarms. Although some environmental effects can be filtered mathematically to reduce a rate of false and nuisance alarms, such algorithms can be computationally intensive and can lead to intermittent operation. Moreover, such mathematical filtering may not satisfactorily reduce the occurrence of false or nuisance alarms.
- sensors e.g., passive fiber-optic sensors
- sensors configured to extend through more than one environment while responding similarly to a given disturbance regardless of the environment.
- Other needs relating to sensing systems are also unmet.
- Some embodiments of such innovations include a sensor having an actual sensitivity that varies along its length.
- a sensor having substantially constant properties along its length typically has a substantially constant actual sensitivity along its length.
- a given disturbance can be conveyed to a sensor through one environment differently than through another environment, making a sensor's response to such a disturbance appear to be environmentally dependent.
- sensors with longitudinally uniform properties exhibit an apparent sensitivity in one portion exposed to a given environment that differs from an apparent sensitivity exhibited by another portion of the sensor positioned in another environment.
- actual sensitivity means a measure of a sensor's response to a given disturbance in a selected reference environment.
- apparatus sensitivity means a measure of a sensor's response to a given disturbance in an arbitrary environment. For example, a singlemode interferometer buried in the ground might produce 10 interference fringes in response to a given physical disturbance. The same interferometer (or a portion thereof) positioned above-ground might produce 500 interference fringes in response to a similar disturbance.
- a sensor having longitudinally varying optical properties, and a corresponding longitudinally varying actual sensitivity can provide a substantially constant apparent sensitivity when the sensor extends through a variety of environments.
- innovative optical sensors are disclosed in which the respective actual sensitivity of one or more portions of the sensor correspond, at least in part, to a selected environment of the respective sensor portions.
- some disclosed sensors have a plurality of optical conduits extending longitudinally of the sensors. At least one of the optical conduits can have at least one longitudinally extending segment having one or more optical and/or mechanical properties (e.g., birefringence, fiber coating, sheaths, etc.) that differ from the optical properties of an adjacent longitudinally extending segment, thus providing the conduit with longitudinally varying signal propagation characteristics.
- An optical sensor having one or more such optical conduits can exhibit a longitudinally varying actual sensitivity. Nonetheless, such a sensor can exhibit a substantially constant apparent sensitivity, such as when the sensor extends through a plurality of environments (e.g., as a pipeline can), particularly when each respective portion of the sensor exhibits an actual sensitivity corresponding to a selected environment.
- Such an innovative sensor can provide a low-incidence of false or nuisance alarms, as well as accurate position and magnitude information.
- Some innovative systems comprise a method for detecting a disturbance with a sensor having a position-dependent actual sensitivity.
- a position of a disturbance can be determined, and, in some instances, a magnitude of such a disturbance can also be determined when the sensor spans a variety of environments (e.g., above ground, below ground, underwater and through open atmosphere).
- Some disclosed sensors are passively terminated and are configured to extend, for example, up to and even more than about 50 km away from active components. Some disclosed systems have two such sensors extending from the active components in opposite directions relative to each other, providing a disturbance-detection capability over large distances, for example, up to about 100-130 km.
- FIG. 1 shows aspects of an innovative interferometer of the type disclosed herein.
- FIG. 2 shows aspects of another innovative interferometer system of the type disclosed herein.
- FIG. 3 shows a schematic illustration of a commercially available Mach Zehnder interferometer configured to use counter-propagating optical signals having actively matched polarization states.
- FIG. 4 shows aspects of a sensor configured to provide an actual sensitivity that varies with longitudinal position; a portion of the sensor is shown in an enlarged view.
- FIG. 5A shows a cross-sectional view taken along line 5 A- 5 A in FIG. 4 .
- FIG. 5B shows the cross-sectional view in FIG. 5A with several different pairings of optical conduits identified. Each unique combination provides the optical cable with a corresponding unique actual sensitivity.
- FIG. 6 shows a cross-sectional view taken along line 6 - 6 in FIG. 4 .
- FIG. 7 shows a sensor of the type disclosed herein extending among various environments, as when installed, for example, to monitor a pipeline.
- optical conduits and interferometer systems are described herein by way of reference to exemplary embodiments. One or more of the disclosed principles can be incorporated in various configurations to achieve one or more performance characteristics. Disclosed embodiments of optical conduits and interferometer systems relating to perimeter security applications are merely examples used to illustrate one or more of the innovative principles described herein. Some embodiments may be equally applicable to use in many other applications, such as, for example, detecting a leak in a pipeline, detecting a failure in a structure, detecting a disturbance to a ground surface, detecting a change in operation of a conveyor, etc.
- Interferometer systems as disclosed herein can detect a disturbance to a sensor portion by comparing a phase shift between observed first and second optical signals that have travelled through a first (e.g., a “reference”) optical conduit and a second (e.g., a “sensor”) optical conduit.
- a first optical conduit e.g., a “reference” optical conduit
- a second optical conduit e.g., a “sensor” optical conduit.
- one or more optical and/or mechanical properties differ between the first optical conduit and the second optical conduit.
- the innovative interferometer 100 shown in FIG. 1 is configured as a hybrid Michelson/Mach-Zehnder interferometer having an active portion 132 a, as disclosed in the System Patent Application identified above, and a passive portion 130 a .
- the interferometer 100 a shown in FIG. 2 is also configured as a hybrid Michelson/Mach-Zehnder interferometer having an active portion 132 b that includes a polarization scrambler, and a passive portion 130 b.
- the systems 100 , 100 a include respective passive optical sensor portions 130 a, 130 b extending away from the respective active portions 132 a, 132 b toward a distal end 118 .
- FIG. 3 shows an interferometer system having overlapping first and second Mach-Zehnder interferometers configured to convey counter propagating optical signals.
- a disturbance to one or both of the optical conduits 114 a, 114 b (or 114 a ′, 114 b ′, or the sensor portion of the overlapping Mach-Zehnder interferometers shown in FIG. 3 ) can modify each respective optical signal conveyed through the disturbed conduit. By observing such a modified signal, the existence of such a disturbance can be detected, and, in some instances, the position and magnitude of the disturbance can be identified.
- first and second optical conduits 114 a, 114 b ( FIG. 1 ), 114 a ′, 114 b ′ ( FIG. 2 ) can have similar optical and/or mechanical properties and similar lengths.
- the reference and sensor optical conduits are physically separate conduits positioned adjacent each other in a “bundle” (also referred to as a “cable”).
- a conventional fiber optic bundle can include several individual optical fibers (e.g., single-mode fibers) shrouded by an outer sheath(s).
- One of the individual optical fibers can define the sensor conduit (e.g., 114 a ) and another of the individual optical fibers can define the reference conduit (e.g., 114 b ).
- Yet another of the individual optical fibers can define a return conduit, such as in a passively terminated sensor as disclosed in System Patent Application identified above.
- Respective fibers defining the sensor, reference and return conduits can be positioned within and shrouded by the common outer sheath(s).
- optical fibers are usually positioned relatively close to each other (e.g., within several millimeters of each other), a load or other force that alters the optical phase of the signals in the individual optical conduits (e.g., an impact or perturbation) applied to the outer sheath will be transmitted to each of the individual fibers slightly differently.
- each of the individual fibers can respond (e.g., deform or momentarily have its refractive index changed) to identical loads somewhat differently.
- a disturbance to the cable generally will perturb the reference and the signal conduits 114 a, 114 b differently.
- the magnitude and position of a disturbance can be determined using a system as shown in FIGS. 1 , 2 and 3 .
- a nominal, or baseline, phase shift between observed signals of undisturbed reference and sensor conduits can be determined.
- a sensor cable e.g., a bundle having a sensor conduit and a reference conduit
- a sufficiently large (or a threshold) deviation from a baseline phase shift is observed.
- observing such a phase-shift at more than one location through the optical path combined with characteristics of the sensor cable (e.g., its length, the speed at which light travels through each of the optical conduits, optical wavelength), a location of the disturbance can be inferred.
- a third, insensitive conduit can be positioned adjacent one or both of the sensor conduit (e.g., conduit 114 a ) and the reference conduit (e.g., conduit 114 b ).
- an optical cable can have a plurality of optical conduits within a common sheath(s), as described above, and shown in FIG. 5A .
- a disturbance e.g., an impact or perturbation
- a disturbance to an environment surrounding or adjacent to a sensor cable 130 a, 130 b, 130 c can be transmitted to the cable differently in one environment than in another environment.
- a load transmitted to an underground sensor and arising from a given disturbance typically differs from a load transmitted to an above-ground sensor arising from the same disturbance.
- a disturbance to each respective optical conduit in a sensor typically corresponds, at least in part, to the environment through which the sensor extends.
- effects of such a disturbance on an optical signal propagating through the respective optical conduits also correspond, at least in part, to the environment. It is believed that such effects at least partially contribute to observed variations in apparent sensitivity for a given sensor with longitudinally uniform properties extending through different environments.
- an optical sensor with a substantially constant actual sensitivity along its length can respond to disturbances in different environments differently, making it difficult to discern whether an observed event corresponds to a disturbance of the type intended to be sensed with systems of the types shown in FIGS. 1 , 2 and 3 . Accordingly, such an optical sensor can be prone to initiating “false” or “nuisance” alarms when the sensor extends through more than one environment. Although some false or nuisance alarms can be filtered mathematically, such algorithms can be computationally intensive and can lead to intermittent operation, without satisfactorily reducing the occurrence of false or nuisance alarms.
- a “reference-sensor pair” means a selected pair of optical conduits (e.g., 114 a, 114 b ) configured to convey respective optical signals and to operatively couple to one or more components (e.g., 132 a, 132 b ) configured to respond to one or both of the optical signals.
- Fiber optic sensors having longitudinally varying sensitivity are now described.
- a distance between selected optical conduits forming a reference-sensor pair of conduits, a construction of each in the pair of conduits, or both can vary along the sensor's length.
- Other physical characteristics e.g., length, birefringence, sheath construction, cable fill material, polarization
- FIG. 4 schematically illustrates one example 230 of an optical sensor having an actual sensitivity that varies longitudinally.
- FIGS. 5A and 5B show a six-bundle cable capable of providing at least five different actual sensitivities, as described more fully below.
- the senor 230 extends between a proximal end 231 configured to operatively couple to an active portion of an interferometer (e.g., an interferometer 100 , 100 a, 100 b shown in FIGS. 1 through 3 , respectively) and a distal end 232 .
- an interferometer e.g., an interferometer 100 , 100 a, 100 b shown in FIGS. 1 through 3 , respectively
- the sensor 230 can be passively terminated at or near its distal end 232 .
- the illustrated sensor 230 includes four segments 233 , 235 , 237 , 239 , each being configured to provide a respective actual sensitivity to disturbances.
- a first segment 233 extends between the proximal end 231 and a first joint 234 ;
- a second segment 235 extends between the first joint 234 and a second joint 236 ;
- a third segment 237 extends between the second joint 236 and a third joint 238 ;
- a fourth segment 239 extends between the third joint 238 and the distal end 232 .
- each of the first, second, third and fourth segments of the sensor 230 can be operatively configured to provide a corresponding unique actual sensitivity.
- each of the illustrated segments 233 , 235 , 237 , 239 has a substantially identical construction.
- the segment 235 includes six optical conduits 241 , 242 , 243 , 244 , 246 , 247 , each extending longitudinally of the segment; two such longitudinally extending conduits 243 , 244 are shown in FIG. 6 .
- the optical conduits e.g., optical bundles
- the optical conduits are circumferentially spaced from each other (e.g., at about 60-degrees from each other) around a central, longitudinal axis of the cable.
- conduits 243 , 244 , 246 and 247 include tight-buffered fibers and are arranged in opposing pairs relative to the central longitudinal axis.
- the other two conduits 241 , 242 include loose-tube fibers and are positioned about 180-degrees from each other, each being positioned between two respective of the conduits 243 , 244 , 246 and 247 having tight-buffered fibers.
- Each of the six optical conduits can include at least one single-mode optical conduit.
- tight-buffered fibers means a group of longitudinally extending optical fibers that are tightly packed (or held) into an operative structure and surrounding by dry materials. The tight-buffer fibers typically have a 900 micron outer diameter.
- loose-tube fibers means a group of longitudinally extending optical fibers that are free-floating in a viscous (e.g., Newtonian) fluid, a gel, or a non-Newtonian fluid inside a dedicated fiber housing within the cable. In some configurations, such a housing can be a tube.
- Such a gel or fluid can tend to dampen a disturbance to the loose-tube fibers.
- the loose-tube fibers typically have a 250 micron outer diameter.
- Each fiber housing encasing the loose-tube fibers can have a plurality of fibers within, such as, for example, 6 or 12 fibers. Tight-buffered fibers are typically more responsive to a disturbance than loose-tube fibers.
- an outer sheath 251 extends longitudinally of each segment 233 , 235 , 237 , 239 .
- Interstitial spaces 250 , 250 a in each segment can be filled with a suitable strengthening, packing and/or protective material.
- a suitable fill includes fiber-reinforced plastic, Kevlar fibers, water absorbing fabrics/tapes or other materials.
- the interstitial spaces are filled with a material that dampens disturbances to the sheath 251 , and in other instances the interstitial spaces are filled with a material that conveys such disturbances with minimal losses.
- Each segment 233 , 235 , 237 , 239 has a respective reference-sensor pair of optical conduits.
- FIG. 5B shows several possible reference-sensor pairs from which the respective reference-sensor pair can be selected.
- a reference-sensor pair for a given segment 233 , 235 , 237 , 239 can be formed from: (1) opposing tight-buffered fibers 243 , 244 ; (2) opposing loose-tube fibers 241 , 242 ; (3) loose-tube fibers 241 and adjacent tight-buffered fibers 243 ; (4) adjacent tight-buffered fibers 243 , 246 ; or (5) a pair of loose-tube fibers 241 or 242 within a common loose-tube housing.
- each segment 233 , 235 , 237 , 239 can have a unique actual sensitivity even though each segment has a substantially identical overall construction.
- segment 233 can have the first (1) reference-sensor pair
- segment 235 can have the second (2) reference-sensor pair
- segment 237 can have the third (3) reference-sensor pair
- segment 239 can have the fourth (4) reference-sensor pair.
- Each of these reference-sensor pairs can be expected to differ in response to a disturbance, but each segment has a substantially identical construction, as explained above.
- a portion 240 of the sensor is shown in longitudinal cross-section.
- Adjacent segments 235 , 237 having substantially identical construction are shown, although the reference-sensor pairs differ in each segment, as just described. Nonetheless, the segment 235 can be operatively coupled to the adjacent segment 237 using a conventional optical joint (e.g., fusion splice, mechanical splice, butt splice, etc.) 245 a, 245 b configured to join longitudinally adjacent conduits (e.g., to join conduit 241 to conduit 243 and conduit 242 to conduit 244 , respectively).
- a joint can be an optical fiber fusion splice or a mechanical coupling.
- conduit 241 can be a loose-tube optical fiber and conduit 243 can be a tight-buffered fiber.
- portion 240 of the optical sensor 230 can achieve an actual sensitivity that varies longitudinally (e.g., from segment 235 to segment 237 ).
- Respective segments joined e.g., in end-to-end abutment as just described can provide a sensor 230 having an actual sensitivity that varies longitudinally, despite that the configuration of each segment can be substantially identical to each other. Nonetheless, each segment can have a unique configuration relative to one or more of the other segments, providing a more pronounced difference in actual sensitivity from the other segments.
- the actual sensitivity (and a corresponding reference-sensor pair) of the first segment 233 can be selected to correspond with one or more characteristics of the corresponding intended environment 260 a (e.g., underground).
- the segment 233 can be configured to achieve a first apparent sensitivity when the sensor 230 is exposed to the environment 260 a.
- the actual sensitivity of the second segment 235 can be selected to correspond with one or more characteristics of the corresponding intended environment 260 b (e.g., a wetland).
- the segment 235 can be configured (e.g., by selecting a reference-sensor pair configuration) to achieve a second apparent sensitivity when the sensor 230 is installed in the environment 260 b.
- the actual sensitivity of the third segment 237 and the fourth segment 239 can be selected to correspond with one or more characteristics of the corresponding intended environments 260 c (e.g., under water), 260 d (e.g., in the air) such that the segments 237 , 239 achieve respective third and fourth apparent sensitivities when the sensor 230 is installed.
- the respective first, second, third and fourth apparent sensitivities can be more closely matched to each other than corresponding portions of a sensor having a longitudinally constant actual sensitivity would exhibit when extending among the different environments 260 a, 260 b, 260 c, 260 d.
- the actual sensitivity of each respective segment differs from the actual sensitivity of each of the other segments; in other instances, the actual sensitivity of each of two or more respective segments is substantially the same.
- the sensor 230 is shown as having four segments 233 , 235 , 237 , 239 , alternative sensor embodiments can have more or fewer segments. The number of segments (and respective actual sensitivities) can be selected to correspond to the number and types of environments the sensor is expected to be exposed to in use.
- segments 233 , 235 , 237 , 239 are shown and described as having six optical conduits circumferentially spaced from each other, other segment configurations are possible.
- a segment can have more or fewer longitudinally extending optical conduits than shown in FIGS. 5A and 5B .
- Optical conduits can be spaced at other than 60-degrees from each other (even when six optical conduits are present in a given segment).
- a segment can have more or fewer tight-buffered or loose-tube conduits.
- any suitable optical conduit can be used.
- optical conduits exhibiting two classes of signal propagation or mechanical characteristics e.g., “loose-tube fibers” and “tight-buffered fibers”
- the disclosed principles apply to segments having a group of conduits that exhibit more than two classes of signal propagation characteristics.
- Such characteristics include, by way of example, birefringence, length, phase, propagation time, polarization and coating type.
- each pair of optical conduits selected as the operative reference-sensor pair can provide the segment with a unique actual sensitivity.
- the range of achievable actual sensitivities can correspond, at least in part, to the physical and optical characteristics and relative locations of each in the pair of conduits, as well as to the overall configuration (e.g., the number of optical conduits in the bundle, the respective location of each conduit within the bundle, whether one or more interstitial spaces of the bundle is filled, and if so, the material used to fill the spaces).
- a multi-segment sensor e.g., the sensor 230 shown in FIG.
- a respective pair of optical conduits can be selected as the reference-sensor pair based, at least in part, to correspond with a known, or selected, environmental characteristics (e.g., material properties related to vibration-transmission through an environmental material, such as, for example, soil, water or air).
- environmental characteristics e.g., material properties related to vibration-transmission through an environmental material, such as, for example, soil, water or air.
- a sensor can have a continually varying actual sensitivity along its length. In other instances, the sensor can have a stepwise or discretely varying actual sensitivity along its length, as with the sensor 230 shown in FIG. 4 . In some instances, a sensor having individual segments with respective lengths less than or on the order of a spatial resolution of the sensor can exhibit one or more characteristics of a sensor having a continuously varying sensitivity.
- a sensor can have only one optical conduit to make up the reference-sensor pair (eg., a Sagnac interferometer or a modalmetric sensor). In other cases, more than two optical conduits may be used to create the sensor.
- interferometer systems particularly those configured to detect a disturbance with a sensor extending among two or more environments.
- Michelson and Mach-Zehnder interferometers have been described above in some detail
- sensors disclosed herein can be used with a variety of other types of interferometers, such as, for example, overlapping first and second Mach Zehnder interferometers, a Sagnac interferometer, a modalmetric sensor, an optical time domain reflectometer (OTDR), such as, for example, a coherent-OTDR interferometer, a polarimeter, and many other interferometer configurations.
- OTDR optical time domain reflectometer
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Analytical Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Instruments For Measurement Of Length By Optical Means (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Optical Transform (AREA)
Abstract
Description
- This application claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 61/393,298 and U.S. Provisional Patent Application Ser. No. 61/393,321 (referred to hereinafter as the “System Patent Application”), both filed Oct. 14, 2010, the contents of which are hereby incorporated by reference as if recited in full herein for all purposes.
- The innovations disclosed herein pertain to interferometer systems, and more particularly, but not exclusively, to fiber-optic interferometer systems having variable-sensitivity sensors. Some innovative interferometer systems are configured to detect and/or locate disturbances (e.g., a disturbance to a secure perimeter, such as a “tap” on a fence, a leak from a pipeline, a change in structural integrity of a bridge, a disturbance to a communication line, a change in operation of a conveyor belt, an impact on a surface or acoustical noise, among others). In some instances, such systems can be configured to detect and/or locate over distances up to, for example, about 65 kilometers (km) with one passive sensor, and up to, for example, about 130 km with first and second passive sensors extending in opposite directions.
- Most optical conduits (e.g., optical fibers) have substantially uniform (e.g., unvarying) properties along their lengths, making such optical conduits suitable for a wide variety of applications (e.g., communications, interferometers) that demand homogeneous properties. This homogeneity is a result of, among many factors, modern high-quality manufacturing processes for optical fibers, coatings on the optical fibers and various protective sheaths of the cable in which the fibers are typically encased. When used as a sensor configured to detect a disturbance, such longitudinally homogeneous optical conduits typically respond to a given perturbation in a uniform manner, regardless of where the perturbation is applied along the sensor's length.
- In many applications, different portions of a given sensor can be exposed to respective different environments. For example, a portion of a sensor can be positioned, for example, under water, another portion can be positioned underground and yet another portion can be positioned above-ground (e.g., exposed to the atmosphere). In such an application, known sensors can respond to a given disturbance differently depending, for example, on the environment and which portion of the sensor is perturbed. Therefore, with known sensors having homogeneous sensitivity, it can be difficult to discern one or more characteristics (e.g., amplitude, position, etc.) of any particular disturbance, particularly if the environmental surroundings vary along the sensor's length. Accordingly, known fiber-optic sensors can be prone to initiating “false” or “nuisance” alarms. Although some environmental effects can be filtered mathematically to reduce a rate of false and nuisance alarms, such algorithms can be computationally intensive and can lead to intermittent operation. Moreover, such mathematical filtering may not satisfactorily reduce the occurrence of false or nuisance alarms.
- Accordingly, there remains a need for sensors, e.g., passive fiber-optic sensors, configured to extend through more than one environment while responding similarly to a given disturbance regardless of the environment. Other needs relating to sensing systems are also unmet.
- Innovative optical sensors and related interferometer systems addressing one or more of the above-identified and other needs are disclosed. Some embodiments of such innovations include a sensor having an actual sensitivity that varies along its length.
- A sensor having substantially constant properties along its length typically has a substantially constant actual sensitivity along its length. A given disturbance can be conveyed to a sensor through one environment differently than through another environment, making a sensor's response to such a disturbance appear to be environmentally dependent. Moreover, sensors with longitudinally uniform properties exhibit an apparent sensitivity in one portion exposed to a given environment that differs from an apparent sensitivity exhibited by another portion of the sensor positioned in another environment. As used herein, “actual sensitivity” means a measure of a sensor's response to a given disturbance in a selected reference environment. As used herein, “apparent sensitivity” means a measure of a sensor's response to a given disturbance in an arbitrary environment. For example, a singlemode interferometer buried in the ground might produce 10 interference fringes in response to a given physical disturbance. The same interferometer (or a portion thereof) positioned above-ground might produce 500 interference fringes in response to a similar disturbance.
- In contrast to a sensor having longitudinally homogeneous optical properties, a sensor having longitudinally varying optical properties, and a corresponding longitudinally varying actual sensitivity, can provide a substantially constant apparent sensitivity when the sensor extends through a variety of environments. Innovative optical sensors are disclosed in which the respective actual sensitivity of one or more portions of the sensor correspond, at least in part, to a selected environment of the respective sensor portions.
- For example, some disclosed sensors have a plurality of optical conduits extending longitudinally of the sensors. At least one of the optical conduits can have at least one longitudinally extending segment having one or more optical and/or mechanical properties (e.g., birefringence, fiber coating, sheaths, etc.) that differ from the optical properties of an adjacent longitudinally extending segment, thus providing the conduit with longitudinally varying signal propagation characteristics. An optical sensor having one or more such optical conduits can exhibit a longitudinally varying actual sensitivity. Nonetheless, such a sensor can exhibit a substantially constant apparent sensitivity, such as when the sensor extends through a plurality of environments (e.g., as a pipeline can), particularly when each respective portion of the sensor exhibits an actual sensitivity corresponding to a selected environment. Such an innovative sensor can provide a low-incidence of false or nuisance alarms, as well as accurate position and magnitude information.
- Some innovative systems comprise a method for detecting a disturbance with a sensor having a position-dependent actual sensitivity. With some embodiments of such innovative systems, a position of a disturbance can be determined, and, in some instances, a magnitude of such a disturbance can also be determined when the sensor spans a variety of environments (e.g., above ground, below ground, underwater and through open atmosphere).
- Some disclosed sensors are passively terminated and are configured to extend, for example, up to and even more than about 50 km away from active components. Some disclosed systems have two such sensors extending from the active components in opposite directions relative to each other, providing a disturbance-detection capability over large distances, for example, up to about 100-130 km.
- The foregoing and other features and advantages will become more apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
- The accompanying drawings show aspects of the innovative systems disclosed herein, unless specifically identified as showing a known feature from the prior art.
-
FIG. 1 shows aspects of an innovative interferometer of the type disclosed herein. -
FIG. 2 shows aspects of another innovative interferometer system of the type disclosed herein. -
FIG. 3 shows a schematic illustration of a commercially available Mach Zehnder interferometer configured to use counter-propagating optical signals having actively matched polarization states. -
FIG. 4 shows aspects of a sensor configured to provide an actual sensitivity that varies with longitudinal position; a portion of the sensor is shown in an enlarged view. -
FIG. 5A shows a cross-sectional view taken alongline 5A-5A inFIG. 4 .FIG. 5B shows the cross-sectional view inFIG. 5A with several different pairings of optical conduits identified. Each unique combination provides the optical cable with a corresponding unique actual sensitivity. -
FIG. 6 shows a cross-sectional view taken along line 6-6 inFIG. 4 . -
FIG. 7 shows a sensor of the type disclosed herein extending among various environments, as when installed, for example, to monitor a pipeline. - Various principles related to optical conduits and interferometer systems are described herein by way of reference to exemplary embodiments. One or more of the disclosed principles can be incorporated in various configurations to achieve one or more performance characteristics. Disclosed embodiments of optical conduits and interferometer systems relating to perimeter security applications are merely examples used to illustrate one or more of the innovative principles described herein. Some embodiments may be equally applicable to use in many other applications, such as, for example, detecting a leak in a pipeline, detecting a failure in a structure, detecting a disturbance to a ground surface, detecting a change in operation of a conveyor, etc.
- Some innovative optical conduits disclosed herein can be combined with known interferometer configurations to provide levels of performance that heretofore have been unachievable. Examples of such innovative combinations are described below.
- Interferometer systems as disclosed herein can detect a disturbance to a sensor portion by comparing a phase shift between observed first and second optical signals that have travelled through a first (e.g., a “reference”) optical conduit and a second (e.g., a “sensor”) optical conduit. In systems disclosed herein, one or more optical and/or mechanical properties differ between the first optical conduit and the second optical conduit.
- For example, the
innovative interferometer 100 shown inFIG. 1 is configured as a hybrid Michelson/Mach-Zehnder interferometer having anactive portion 132 a, as disclosed in the System Patent Application identified above, and apassive portion 130 a. Theinterferometer 100 a shown inFIG. 2 is also configured as a hybrid Michelson/Mach-Zehnder interferometer having anactive portion 132 b that includes a polarization scrambler, and apassive portion 130 b. As shown inFIGS. 1 and 2 , thesystems optical sensor portions active portions distal end 118. -
FIG. 3 shows an interferometer system having overlapping first and second Mach-Zehnder interferometers configured to convey counter propagating optical signals. - A disturbance to one or both of the
optical conduits FIG. 3 ) can modify each respective optical signal conveyed through the disturbed conduit. By observing such a modified signal, the existence of such a disturbance can be detected, and, in some instances, the position and magnitude of the disturbance can be identified. - In some instances, the first and second
optical conduits FIG. 1 ), 114 a′, 114 b′ (FIG. 2 ) can have similar optical and/or mechanical properties and similar lengths. In some embodiments, the reference and sensor optical conduits are physically separate conduits positioned adjacent each other in a “bundle” (also referred to as a “cable”). - For example, a conventional fiber optic bundle can include several individual optical fibers (e.g., single-mode fibers) shrouded by an outer sheath(s). One of the individual optical fibers can define the sensor conduit (e.g., 114 a) and another of the individual optical fibers can define the reference conduit (e.g., 114 b). Yet another of the individual optical fibers can define a return conduit, such as in a passively terminated sensor as disclosed in System Patent Application identified above. Respective fibers defining the sensor, reference and return conduits can be positioned within and shrouded by the common outer sheath(s). Although such optical fibers are usually positioned relatively close to each other (e.g., within several millimeters of each other), a load or other force that alters the optical phase of the signals in the individual optical conduits (e.g., an impact or perturbation) applied to the outer sheath will be transmitted to each of the individual fibers slightly differently. Moreover, each of the individual fibers can respond (e.g., deform or momentarily have its refractive index changed) to identical loads somewhat differently. Thus, in practice, a disturbance to the cable generally will perturb the reference and the
signal conduits - Since physical responses typically differ between the “sensor” conduit and the “reference” conduit, light travelling through the “sensor” conduit can arrive at a terminal end of the sensor conduit (
FIGS. 1 , 2 and 3) at a slightly different time, and possibly with a different polarization state, than light travelling through the “reference” conduit. Thus, optical signals observed at each respective terminal end will usually be out of phase from each other by some amount. When either or both of the sensor and reference conduits has been disturbed, the relative phase of the optical signals observed at each respective terminal end will tend to shift from the nominal level from the undisturbed conduits. By comparing a delay between the first of the optical signals and the second of the optical signals (e.g., an observed phase-shift between the signals), and accounting for characteristics of the interferometer components (e.g., lengths of optical conduits, speed of light through the conduits, optical wavelength), the magnitude and position of a disturbance can be determined using a system as shown inFIGS. 1 , 2 and 3. - Although many factors can cause an observed phase shift between signals conveyed through the first and second optical conduits, a nominal, or baseline, phase shift between observed signals of undisturbed reference and sensor conduits can be determined. Thus, one can infer that a sensor cable (e.g., a bundle having a sensor conduit and a reference conduit) has been disturbed when a sufficiently large (or a threshold) deviation from a baseline phase shift is observed. In addition, observing such a phase-shift at more than one location through the optical path, combined with characteristics of the sensor cable (e.g., its length, the speed at which light travels through each of the optical conduits, optical wavelength), a location of the disturbance can be inferred.
- As noted above, in some embodiments, a third, insensitive conduit can be positioned adjacent one or both of the sensor conduit (e.g.,
conduit 114 a) and the reference conduit (e.g.,conduit 114 b). For example, an optical cable can have a plurality of optical conduits within a common sheath(s), as described above, and shown inFIG. 5A . - As described above, a disturbance (e.g., an impact or perturbation) applied to the outer sheath of a cable typically will be transmitted to each of the individual optical conduits slightly differently. In addition, a disturbance to an environment surrounding or adjacent to a
sensor cable - As a consequence, effects of such a disturbance on an optical signal propagating through the respective optical conduits also correspond, at least in part, to the environment. It is believed that such effects at least partially contribute to observed variations in apparent sensitivity for a given sensor with longitudinally uniform properties extending through different environments.
- As noted above, an optical sensor with a substantially constant actual sensitivity along its length can respond to disturbances in different environments differently, making it difficult to discern whether an observed event corresponds to a disturbance of the type intended to be sensed with systems of the types shown in
FIGS. 1 , 2 and 3. Accordingly, such an optical sensor can be prone to initiating “false” or “nuisance” alarms when the sensor extends through more than one environment. Although some false or nuisance alarms can be filtered mathematically, such algorithms can be computationally intensive and can lead to intermittent operation, without satisfactorily reducing the occurrence of false or nuisance alarms. - As explained above, differing physical responses between a selected pair of optical conduits (e.g., the
conduits - Fiber optic sensors having longitudinally varying sensitivity are now described. For example, a distance between selected optical conduits forming a reference-sensor pair of conduits, a construction of each in the pair of conduits, or both, can vary along the sensor's length. Other physical characteristics (e.g., length, birefringence, sheath construction, cable fill material, polarization) can also vary along the sensor's length and provide a longitudinally varying physical response between selected reference-sensor pairs.
FIG. 4 schematically illustrates one example 230 of an optical sensor having an actual sensitivity that varies longitudinally.FIGS. 5A and 5B show a six-bundle cable capable of providing at least five different actual sensitivities, as described more fully below. - In
FIG. 4 , thesensor 230 extends between aproximal end 231 configured to operatively couple to an active portion of an interferometer (e.g., aninterferometer FIGS. 1 through 3 , respectively) and adistal end 232. As noted above regarding thesensors sensor 230 can be passively terminated at or near itsdistal end 232. - The illustrated
sensor 230 includes foursegments first segment 233 extends between theproximal end 231 and a first joint 234; asecond segment 235 extends between the first joint 234 and a second joint 236; athird segment 237 extends between the second joint 236 and a third joint 238; and afourth segment 239 extends between the third joint 238 and thedistal end 232. As will now be described, each of the first, second, third and fourth segments of thesensor 230 can be operatively configured to provide a corresponding unique actual sensitivity. - Each of the illustrated
segments FIG. 5A , thesegment 235 includes sixoptical conduits longitudinally extending conduits FIG. 6 . In each segment shown inFIG. 4 , the optical conduits (e.g., optical bundles) are circumferentially spaced from each other (e.g., at about 60-degrees from each other) around a central, longitudinal axis of the cable. Four of the six conduits, i.e.,conduits conduits conduits - Each of the six optical conduits can include at least one single-mode optical conduit. As used herein, “tight-buffered fibers” means a group of longitudinally extending optical fibers that are tightly packed (or held) into an operative structure and surrounding by dry materials. The tight-buffer fibers typically have a 900 micron outer diameter. As used herein, “loose-tube fibers” means a group of longitudinally extending optical fibers that are free-floating in a viscous (e.g., Newtonian) fluid, a gel, or a non-Newtonian fluid inside a dedicated fiber housing within the cable. In some configurations, such a housing can be a tube. Such a gel or fluid (e.g., Newtonian or non-Newtonian) can tend to dampen a disturbance to the loose-tube fibers. The loose-tube fibers typically have a 250 micron outer diameter. Each fiber housing encasing the loose-tube fibers can have a plurality of fibers within, such as, for example, 6 or 12 fibers. Tight-buffered fibers are typically more responsive to a disturbance than loose-tube fibers.
- In
FIG. 5 , anouter sheath 251 extends longitudinally of eachsegment Interstitial spaces sheath 251, and in other instances the interstitial spaces are filled with a material that conveys such disturbances with minimal losses. - Each
segment FIG. 5B shows several possible reference-sensor pairs from which the respective reference-sensor pair can be selected. For example, a reference-sensor pair for a givensegment fibers tube fibers tube fibers 241 and adjacent tight-bufferedfibers 243; (4) adjacent tight-bufferedfibers tube fibers - Since the actual sensitivity relates, at least in part, to a distance separating the respective reference-sensor pair and the construction of each in the pair of fibers, each
segment segment 233 can have the first (1) reference-sensor pair,segment 235 can have the second (2) reference-sensor pair,segment 237 can have the third (3) reference-sensor pair, andsegment 239 can have the fourth (4) reference-sensor pair. Each of these reference-sensor pairs can be expected to differ in response to a disturbance, but each segment has a substantially identical construction, as explained above. - In
FIG. 6 , aportion 240 of the sensor is shown in longitudinal cross-section.Adjacent segments segment 235 can be operatively coupled to theadjacent segment 237 using a conventional optical joint (e.g., fusion splice, mechanical splice, butt splice, etc.) 245 a, 245 b configured to join longitudinally adjacent conduits (e.g., to joinconduit 241 toconduit 243 andconduit 242 toconduit 244, respectively). Such a joint can be an optical fiber fusion splice or a mechanical coupling. - Operatively joined conduits can have different constructions. For example,
conduit 241 can be a loose-tube optical fiber andconduit 243 can be a tight-buffered fiber. With such a construction, theportion 240 of theoptical sensor 230 can achieve an actual sensitivity that varies longitudinally (e.g., fromsegment 235 to segment 237). Respective segments joined (e.g., in end-to-end abutment) as just described can provide asensor 230 having an actual sensitivity that varies longitudinally, despite that the configuration of each segment can be substantially identical to each other. Nonetheless, each segment can have a unique configuration relative to one or more of the other segments, providing a more pronounced difference in actual sensitivity from the other segments. - When such a
sensor 230 extends amongdifferent environments FIGS. 4 , 6 and 7), variations in the apparent sensitivity of thesensor 230 can be substantially reduced compared to a sensor having a longitudinally constant actual sensitivity extending among the environments. - For example, with a sensor as shown in
FIG. 7 , the actual sensitivity (and a corresponding reference-sensor pair) of thefirst segment 233 can be selected to correspond with one or more characteristics of the corresponding intendedenvironment 260 a (e.g., underground). Thus, thesegment 233 can be configured to achieve a first apparent sensitivity when thesensor 230 is exposed to theenvironment 260 a. In a similar fashion, the actual sensitivity of thesecond segment 235 can be selected to correspond with one or more characteristics of the corresponding intendedenvironment 260 b (e.g., a wetland). Accordingly, thesegment 235 can be configured (e.g., by selecting a reference-sensor pair configuration) to achieve a second apparent sensitivity when thesensor 230 is installed in theenvironment 260 b. The actual sensitivity of thethird segment 237 and thefourth segment 239, respectively, can be selected to correspond with one or more characteristics of the corresponding intendedenvironments 260 c (e.g., under water), 260 d (e.g., in the air) such that thesegments sensor 230 is installed. The respective first, second, third and fourth apparent sensitivities can be more closely matched to each other than corresponding portions of a sensor having a longitudinally constant actual sensitivity would exhibit when extending among thedifferent environments - In some sensor embodiments, such as, for example, the
sensor 230 shown inFIG. 4 , the actual sensitivity of each respective segment differs from the actual sensitivity of each of the other segments; in other instances, the actual sensitivity of each of two or more respective segments is substantially the same. Also, although thesensor 230 is shown as having foursegments - In addition, although
segments FIGS. 5A and 5B . Optical conduits can be spaced at other than 60-degrees from each other (even when six optical conduits are present in a given segment). A segment can have more or fewer tight-buffered or loose-tube conduits. - Although “loose-tube fibers” and “tight-buffered fibers” are described, any suitable optical conduit can be used. Also, although optical conduits exhibiting two classes of signal propagation or mechanical characteristics (e.g., “loose-tube fibers” and “tight-buffered fibers”) are described, the disclosed principles apply to segments having a group of conduits that exhibit more than two classes of signal propagation characteristics. Such characteristics include, by way of example, birefringence, length, phase, propagation time, polarization and coating type.
- For a given segment, each pair of optical conduits selected as the operative reference-sensor pair can provide the segment with a unique actual sensitivity. The range of achievable actual sensitivities can correspond, at least in part, to the physical and optical characteristics and relative locations of each in the pair of conduits, as well as to the overall configuration (e.g., the number of optical conduits in the bundle, the respective location of each conduit within the bundle, whether one or more interstitial spaces of the bundle is filled, and if so, the material used to fill the spaces). For each segment in a multi-segment sensor (e.g., the
sensor 230 shown inFIG. 4 ), a respective pair of optical conduits can be selected as the reference-sensor pair based, at least in part, to correspond with a known, or selected, environmental characteristics (e.g., material properties related to vibration-transmission through an environmental material, such as, for example, soil, water or air). - In some instances, a sensor can have a continually varying actual sensitivity along its length. In other instances, the sensor can have a stepwise or discretely varying actual sensitivity along its length, as with the
sensor 230 shown inFIG. 4 . In some instances, a sensor having individual segments with respective lengths less than or on the order of a spatial resolution of the sensor can exhibit one or more characteristics of a sensor having a continuously varying sensitivity. - In some instances, a sensor can have only one optical conduit to make up the reference-sensor pair (eg., a Sagnac interferometer or a modalmetric sensor). In other cases, more than two optical conduits may be used to create the sensor.
- Using the principles disclosed herein, those of ordinary skill will appreciate a wide variety of possible embodiments of interferometer systems, particularly those configured to detect a disturbance with a sensor extending among two or more environments. For example, although Michelson and Mach-Zehnder interferometers have been described above in some detail, sensors disclosed herein can be used with a variety of other types of interferometers, such as, for example, overlapping first and second Mach Zehnder interferometers, a Sagnac interferometer, a modalmetric sensor, an optical time domain reflectometer (OTDR), such as, for example, a coherent-OTDR interferometer, a polarimeter, and many other interferometer configurations.
- This disclosure makes reference to the accompanying drawings which form a part hereof, wherein like numerals designate like parts throughout. The drawings illustrate specific embodiments, but other embodiments may be formed and structural changes may be made without departing from the intended scope of this disclosure. Directions and references (e.g., up, down, top, bottom, left, right, rearward, forward, etc.) may be used to facilitate discussion of the drawings but are not intended to be limiting. For example, certain terms may be used such as “up,” “down,”, “upper,” “lower,” “horizontal,” “vertical,” “left,” “right,” and the like. These terms are used, where applicable, to provide some clarity of description when dealing with relative relationships, particularly with respect to the illustrated embodiments. Such terms are not, however, intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an “upper” surface can become a “lower” surface simply by turning the object over. Nevertheless, it is still the same surface and the object remains the same. As used herein, “and/or” means “and” as well as “and” and “or.”
- Accordingly, this detailed description shall not be construed in a limiting sense, and following a review of this disclosure, those of ordinary skill in the art will appreciate the wide variety of interferometer systems that can be devised and constructed using the various concepts described herein. Moreover, those of ordinary skill in the art will appreciate that the exemplary embodiments disclosed herein can be adapted to various configurations without departing from the disclosed concepts. Thus, in view of the many possible embodiments to which the disclosed principles can be applied, it should be recognized that the above-described embodiments are only examples and should not be taken as limiting in scope. And, although detailed claims have not been presented here since claims are not a necessary component for a provisional patent application, I reserve the right to claim as my invention all that comes within the scope and spirit of the subject matter disclosed herein, including but not limited to all that comes within the scope and spirit of the following paragraphs.
Claims (36)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/879,370 US20130208283A1 (en) | 2010-10-14 | 2011-09-21 | Variable sensitivity interferometer systems |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US39329810P | 2010-10-14 | 2010-10-14 | |
US39332110P | 2010-10-14 | 2010-10-14 | |
PCT/US2011/052610 WO2012050775A1 (en) | 2010-10-14 | 2011-09-21 | Variable sensitivity interferometer systems |
US13/879,370 US20130208283A1 (en) | 2010-10-14 | 2011-09-21 | Variable sensitivity interferometer systems |
Publications (1)
Publication Number | Publication Date |
---|---|
US20130208283A1 true US20130208283A1 (en) | 2013-08-15 |
Family
ID=45938615
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/879,370 Abandoned US20130208283A1 (en) | 2010-10-14 | 2011-09-21 | Variable sensitivity interferometer systems |
US13/499,274 Active 2032-09-27 US8873064B2 (en) | 2010-10-14 | 2011-09-21 | Fiber-optic disturbance detection using combined Michelson and Mach-Zehnder interferometers |
US14/482,644 Active US9400167B2 (en) | 2010-10-14 | 2014-09-10 | Disturbance detection using a passively terminated fiber optic sensor |
Family Applications After (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/499,274 Active 2032-09-27 US8873064B2 (en) | 2010-10-14 | 2011-09-21 | Fiber-optic disturbance detection using combined Michelson and Mach-Zehnder interferometers |
US14/482,644 Active US9400167B2 (en) | 2010-10-14 | 2014-09-10 | Disturbance detection using a passively terminated fiber optic sensor |
Country Status (9)
Country | Link |
---|---|
US (3) | US20130208283A1 (en) |
EP (1) | EP2627966B1 (en) |
KR (2) | KR101522318B1 (en) |
CN (1) | CN103261835B (en) |
AU (1) | AU2011314185B2 (en) |
CA (1) | CA2813869C (en) |
IL (1) | IL225625A (en) |
RU (1) | RU2557324C2 (en) |
WO (2) | WO2012050775A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130222810A1 (en) * | 2010-11-03 | 2013-08-29 | Herve Lefevre | Apolarized interferometric system, and apolarized interferometric measurement method |
Families Citing this family (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140230536A1 (en) * | 2013-02-15 | 2014-08-21 | Baker Hughes Incorporated | Distributed acoustic monitoring via time-sheared incoherent frequency domain reflectometry |
DE102013103756B4 (en) * | 2013-04-15 | 2014-12-11 | Carl Zeiss Ag | Sensor device for underwater applications and method for detecting underwater objects |
WO2015034858A1 (en) * | 2013-09-03 | 2015-03-12 | US Seismic Systems, Inc. | Interferometric sensing systems with polarization noise reduction, and methods of operating the same |
EP3100005A1 (en) | 2014-01-27 | 2016-12-07 | Omnisens S.A. | Optical distributed sensing device and method for measurements over extended ranges |
CN103900799B (en) * | 2014-03-28 | 2016-05-04 | 哈尔滨工程大学 | A kind of optical coherence polarimeter that suppresses interaction noise |
CN104913739B (en) * | 2015-06-26 | 2017-10-27 | 北方工业大学 | Visual measurement method and device for eccentricity of crank throw of crankshaft |
CN105096490B (en) * | 2015-09-02 | 2020-12-25 | 同方威视技术股份有限公司 | Distributed optical fiber perimeter security system, sound restoration system and method |
GB201601060D0 (en) * | 2016-01-20 | 2016-03-02 | Fotech Solutions Ltd | Distributed optical fibre sensors |
WO2018063452A1 (en) | 2016-09-29 | 2018-04-05 | Nlight, Inc. | Adjustable beam characteristics |
CN107677358A (en) * | 2017-09-08 | 2018-02-09 | 国网安徽省电力公司安庆供电公司 | Broken localization method outside a kind of determination circuit |
CN108627099B (en) * | 2018-07-02 | 2020-03-20 | 清华大学 | Five-degree-of-freedom heterodyne grating interferometry system |
CN110345389B (en) * | 2019-06-13 | 2021-02-12 | 安徽陶博士环保科技有限公司 | Pipeline leakage and excavation prevention early warning method and system |
CN110648481B (en) * | 2019-09-12 | 2022-02-15 | 深圳市矽赫科技有限公司 | Calibration method and perimeter alarm device |
RU198732U1 (en) * | 2019-11-27 | 2020-07-23 | Федеральное государственное бюджетное учреждение науки Физический институт им. П.Н. Лебедева Российской академии наук (ФИАН) | OPTICAL DELAY DEVICE FOR SHEARING POLARO INTERFEROMETER |
CN110967048B (en) * | 2019-12-28 | 2021-11-05 | 桂林电子科技大学 | Orthogonal inclined three-core fiber grating parallel integrated Mach-Zehnder interferometer |
RU2765757C1 (en) * | 2020-09-28 | 2022-02-02 | Акционерное Общество "Институт "Оргэнергострой" | Fibre-optic security detector with a linear part with joint interferometers |
RU2769886C2 (en) * | 2020-09-28 | 2022-04-07 | Акционерное Общество "Институт "Оргэнергострой" | Fibre-optic security detector with linear part with combined interferometers |
RU2765763C1 (en) * | 2020-09-28 | 2022-02-02 | Акционерное Общество "Институт "Оргэнергострой" | Linear part with joint interferometers for a fibre-optic security detector |
RU2761370C1 (en) * | 2020-09-28 | 2021-12-07 | Акционерное Общество "Институт "Оргэнергострой" | Fiber-optic security detector with linear part with interferometer with two arms |
CN113223259B (en) * | 2021-05-13 | 2022-10-04 | 太原理工大学 | Optical fiber perimeter security system with variable structure |
WO2023028073A1 (en) * | 2021-08-24 | 2023-03-02 | Deepsight Technology, Inc. | Multi-dimensional signal detection with optical sensors |
CN113984126B (en) * | 2021-11-04 | 2024-05-14 | 武汉理工大学威海研究院 | Temperature strain monitoring system and method based on differently doped double-core weak reflection FBG array |
CN114813576B (en) * | 2022-04-19 | 2023-02-14 | 浙江大学 | Self-adaptive all-fiber laser ultrasonic measuring instrument |
CN114941984B (en) * | 2022-05-07 | 2023-04-14 | 山西大学 | Photoacoustic signal detection device and method of all-optical device |
TWI820724B (en) * | 2022-05-24 | 2023-11-01 | 中華電信股份有限公司 | Optical fiber perimeter intrusion detection system and intrusion detection method |
NL2034108B1 (en) * | 2023-02-07 | 2024-08-29 | Optics11 B V | Optical measurement system |
US12085464B1 (en) * | 2024-02-29 | 2024-09-10 | Vanmok Inc. | System and method for measuring pressure inside pipelines or pressure vessels |
Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3920432A (en) * | 1974-08-30 | 1975-11-18 | Bell Telephone Labor Inc | Method of fabricating an optical fiber ribbon |
US4297887A (en) * | 1980-02-19 | 1981-11-03 | The United States Of America As Represented By The Secretary Of The Navy | High-sensitivity, low-noise, remote optical fiber |
US4363533A (en) * | 1979-12-26 | 1982-12-14 | Gould Inc. | Concentric fiber optical transducer |
US4525818A (en) * | 1979-08-09 | 1985-06-25 | Her Majesty The Queen In Right Of Canada, As Represented By Minister Of National Defence Of Her Majesty's Canadian Government | Stable fiber-optic hydrophone |
GB2197953A (en) * | 1986-11-27 | 1988-06-02 | Plessey Co Plc | Acoustic sensor |
US5144690A (en) * | 1990-12-03 | 1992-09-01 | Corning Incorporated | Optical fiber sensor with localized sensing regions |
US6056436A (en) * | 1997-02-20 | 2000-05-02 | University Of Maryland | Simultaneous measurement of temperature and strain using optical sensors |
GB2368921A (en) * | 1997-09-10 | 2002-05-15 | Western Atlas Int Inc | Optic fibre wellbore logging cable |
US20040258373A1 (en) * | 2003-05-12 | 2004-12-23 | Andreassen Jon Steinar | Monitoring cable |
US20060163457A1 (en) * | 2005-01-11 | 2006-07-27 | Future Fibre Technologies Pty Ltd | Apparatus and method for using a counter-propagating signal method for locating events |
US20110058778A1 (en) * | 2009-05-08 | 2011-03-10 | Brian Herbst | Cable including strain-free fiber and strain-coupled fiber |
WO2011058312A2 (en) * | 2009-11-13 | 2011-05-19 | Qinetiq Limited | Fibre optic distributed sensing |
US20130336612A1 (en) * | 2011-03-09 | 2013-12-19 | Jeremiah Glen Pearce | Integrated fiber optic monitoring system for a wellsite and method of using same |
US20150014521A1 (en) * | 2013-07-10 | 2015-01-15 | Halliburton Energy Services, Inc. | Reducing Disturbance During Fiber Optic Sensing |
US9080949B2 (en) * | 2009-12-23 | 2015-07-14 | Shell Oil Company | Detecting broadside and directional acoustic signals with a fiber optical distributed acoustic sensing (DAS) assembly |
Family Cites Families (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4725141A (en) * | 1984-08-22 | 1988-02-16 | The General Electric Company, P.L.C. | Interferometers |
US4770535A (en) * | 1985-02-08 | 1988-09-13 | The Board Of Trustees Of The Leland Stanford Junior University | Distributed sensor array and method using a pulsed signal source |
US5206924A (en) * | 1992-01-31 | 1993-04-27 | The United States Of America As Represented By The Secretary Of The Navy | Fiber optic Michelson sensor and arrays with passive elimination of polarization fading and source feedback isolation |
US5473459A (en) | 1993-12-03 | 1995-12-05 | Optimux Systems Corporation | Optical telecommunications system using phase compensation interferometry |
US5798834A (en) * | 1996-04-10 | 1998-08-25 | Loral Defense Systems | Interferometric fiber optic method and apparatus for obtaining absolute static measurement using an optical frequency-time profile |
US6667935B2 (en) * | 1998-04-03 | 2003-12-23 | The Board Of Trustees Of The Leland Stanford Junior University | Apparatus and method for processing optical signals from two delay coils to increase the dynamic range of a sagnac-based fiber optic sensor array |
US6289740B1 (en) * | 1998-10-26 | 2001-09-18 | The United States Of America As Represented By The Secretary Of The Navy | Integrated fiber optic strain sensing using low-coherence wavelength-encoded addressing |
KR100715589B1 (en) | 1998-12-18 | 2007-05-10 | 퓨쳐 파이브레 테크놀로지스 피티와이 엘티디 | Apparatus and method for monitoring a structure using a counter-propagating signal method for locating events |
JP4566401B2 (en) * | 2000-12-28 | 2010-10-20 | アンリツ株式会社 | Optical wavelength measuring device |
US6914681B2 (en) * | 2001-08-22 | 2005-07-05 | Agilent Technologies, Inc. | Interferometric optical component analyzer based on orthogonal filters |
CN1444019A (en) * | 2002-03-08 | 2003-09-24 | 电子科技大学 | Optical fibre Michelson interferometer with optic circulator |
US7738109B2 (en) * | 2002-08-20 | 2010-06-15 | The Board Of Trustees Of The Leland Stanford Junior University | Fiber optic sensor using a Bragg fiber |
WO2004033986A1 (en) * | 2002-10-11 | 2004-04-22 | Agilent Technologies, Inc. | Interferometer monitoring |
US6842254B2 (en) * | 2002-10-16 | 2005-01-11 | Fiso Technologies Inc. | System and method for measuring an optical path difference in a sensing interferometer |
EP1353162A1 (en) * | 2002-12-20 | 2003-10-15 | Agilent Technologies Inc | Determination of a device signal response characteristic using multiple varied signals |
CA2467898A1 (en) * | 2004-05-21 | 2005-11-21 | Pure Technologies Ltd. | Fiber optic sensor method and apparatus |
BRPI0418793A (en) * | 2004-05-24 | 2007-10-09 | Prysmian Cavi Sistemi Energia | process and apparatus for manufacturing an optical cable |
US8395782B2 (en) * | 2004-06-15 | 2013-03-12 | Optellios, Inc. | Detection and location of boundary intrusion, using composite variables derived from phase measurements |
US7725026B2 (en) * | 2004-06-15 | 2010-05-25 | Optellios, Inc. | Phase responsive optical fiber sensor |
US7154082B2 (en) * | 2004-08-20 | 2006-12-26 | Pgs Americas, Inc. | Frequency division and/or wavelength division multiplexed recursive fiber optic telemetry scheme for an optical sensor array |
US7499176B2 (en) | 2007-02-13 | 2009-03-03 | Future Fibre Technologies Pty Ltd | Apparatus and method for using a counter-propagating signal method for locating events |
US7139446B2 (en) * | 2005-02-17 | 2006-11-21 | Metris Usa Inc. | Compact fiber optic geometry for a counter-chirp FMCW coherent laser radar |
US7514670B2 (en) | 2005-08-29 | 2009-04-07 | Fiber Sensys Llc | Distributed fiber optic sensor with location capability |
US7339678B2 (en) * | 2005-11-09 | 2008-03-04 | Northrop Grumman Corporation | Method and system of using odd harmonics for phase generated carrier homodyne |
CN200986604Y (en) * | 2006-11-21 | 2007-12-05 | 天津大学 | High phase stability optical fiber transmission line structure |
GB0705240D0 (en) * | 2007-03-14 | 2007-04-25 | Qinetiq Ltd | Phase based sensing |
US7646944B2 (en) * | 2008-05-16 | 2010-01-12 | Celight, Inc. | Optical sensor with distributed sensitivity |
CN100588912C (en) * | 2008-07-30 | 2010-02-10 | 哈尔滨工程大学 | The composite instrument of optical fiber Mach-Zehnder and Michelson interferometer array |
-
2011
- 2011-09-21 KR KR1020137012357A patent/KR101522318B1/en active IP Right Grant
- 2011-09-21 US US13/879,370 patent/US20130208283A1/en not_active Abandoned
- 2011-09-21 EP EP11832980.4A patent/EP2627966B1/en active Active
- 2011-09-21 RU RU2013119231/28A patent/RU2557324C2/en active
- 2011-09-21 CA CA2813869A patent/CA2813869C/en active Active
- 2011-09-21 US US13/499,274 patent/US8873064B2/en active Active
- 2011-09-21 AU AU2011314185A patent/AU2011314185B2/en active Active
- 2011-09-21 WO PCT/US2011/052610 patent/WO2012050775A1/en active Application Filing
- 2011-09-21 KR KR1020137012360A patent/KR20130090414A/en not_active Application Discontinuation
- 2011-09-21 WO PCT/US2011/052608 patent/WO2012050774A1/en active Application Filing
- 2011-09-21 CN CN201180059490.7A patent/CN103261835B/en active Active
-
2013
- 2013-04-08 IL IL225625A patent/IL225625A/en active IP Right Grant
-
2014
- 2014-09-10 US US14/482,644 patent/US9400167B2/en active Active
Patent Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3920432A (en) * | 1974-08-30 | 1975-11-18 | Bell Telephone Labor Inc | Method of fabricating an optical fiber ribbon |
US4525818A (en) * | 1979-08-09 | 1985-06-25 | Her Majesty The Queen In Right Of Canada, As Represented By Minister Of National Defence Of Her Majesty's Canadian Government | Stable fiber-optic hydrophone |
US4363533A (en) * | 1979-12-26 | 1982-12-14 | Gould Inc. | Concentric fiber optical transducer |
US4297887A (en) * | 1980-02-19 | 1981-11-03 | The United States Of America As Represented By The Secretary Of The Navy | High-sensitivity, low-noise, remote optical fiber |
GB2197953A (en) * | 1986-11-27 | 1988-06-02 | Plessey Co Plc | Acoustic sensor |
US5144690A (en) * | 1990-12-03 | 1992-09-01 | Corning Incorporated | Optical fiber sensor with localized sensing regions |
US6056436A (en) * | 1997-02-20 | 2000-05-02 | University Of Maryland | Simultaneous measurement of temperature and strain using optical sensors |
GB2368921A (en) * | 1997-09-10 | 2002-05-15 | Western Atlas Int Inc | Optic fibre wellbore logging cable |
US20040258373A1 (en) * | 2003-05-12 | 2004-12-23 | Andreassen Jon Steinar | Monitoring cable |
US20060163457A1 (en) * | 2005-01-11 | 2006-07-27 | Future Fibre Technologies Pty Ltd | Apparatus and method for using a counter-propagating signal method for locating events |
US20110058778A1 (en) * | 2009-05-08 | 2011-03-10 | Brian Herbst | Cable including strain-free fiber and strain-coupled fiber |
WO2011058312A2 (en) * | 2009-11-13 | 2011-05-19 | Qinetiq Limited | Fibre optic distributed sensing |
US9080949B2 (en) * | 2009-12-23 | 2015-07-14 | Shell Oil Company | Detecting broadside and directional acoustic signals with a fiber optical distributed acoustic sensing (DAS) assembly |
US20130336612A1 (en) * | 2011-03-09 | 2013-12-19 | Jeremiah Glen Pearce | Integrated fiber optic monitoring system for a wellsite and method of using same |
US20150014521A1 (en) * | 2013-07-10 | 2015-01-15 | Halliburton Energy Services, Inc. | Reducing Disturbance During Fiber Optic Sensing |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130222810A1 (en) * | 2010-11-03 | 2013-08-29 | Herve Lefevre | Apolarized interferometric system, and apolarized interferometric measurement method |
US8953169B2 (en) * | 2010-11-03 | 2015-02-10 | Ixblue | Apolarized interferometric system, and apolarized interferometric measurement method |
Also Published As
Publication number | Publication date |
---|---|
CA2813869C (en) | 2016-05-17 |
WO2012050774A1 (en) | 2012-04-19 |
RU2013119231A (en) | 2014-11-20 |
US20150062588A1 (en) | 2015-03-05 |
IL225625A0 (en) | 2013-06-27 |
CA2813869A1 (en) | 2012-04-19 |
RU2557324C2 (en) | 2015-07-20 |
US8873064B2 (en) | 2014-10-28 |
CN103261835B (en) | 2016-12-21 |
EP2627966A4 (en) | 2016-12-21 |
US20120224182A1 (en) | 2012-09-06 |
US9400167B2 (en) | 2016-07-26 |
EP2627966A1 (en) | 2013-08-21 |
KR20130090414A (en) | 2013-08-13 |
WO2012050775A1 (en) | 2012-04-19 |
KR101522318B1 (en) | 2015-05-27 |
AU2011314185A1 (en) | 2013-05-02 |
CN103261835A (en) | 2013-08-21 |
AU2011314185B2 (en) | 2014-10-02 |
IL225625A (en) | 2017-12-31 |
EP2627966B1 (en) | 2018-08-01 |
KR20130085037A (en) | 2013-07-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20130208283A1 (en) | Variable sensitivity interferometer systems | |
AU760272B2 (en) | Intrinsic securing of fibre optic communication links | |
AU747525B2 (en) | Apparatus and method for monitoring a structure using a counter-propagating signal method for locating events | |
US20240044676A1 (en) | Distributed Optical Fibre Vibration Sensor | |
CA2781565A1 (en) | Detecting broadside and directional acoustic signals with a fiber optical distributed acoustic sensing (das) assembly | |
CA2567551A1 (en) | Fibre optic sensor method and apparatus | |
CN102168808A (en) | Distributed optical fiber vibration sensor | |
US6201237B1 (en) | Fiber optic sensor | |
CN101813238B (en) | Sagnac/Mach-Zehnder interferometer profile fiber sensing system and time domain positioning method thereof | |
US20200033186A1 (en) | Low Crosstalk, Common Path, Dual Ring Sagnac Interferometer for Disturbance Sensing | |
AU613497B2 (en) | An interferometric fibre optic network | |
CA2371576A1 (en) | Intrinsic securing of fibre optic communication links | |
Knudsen et al. | Measurements of fundamental thermal induced phase fluctuations in the fiber of a Sagnac interferometer | |
CN101324446B (en) | Destabilization sensing localization method | |
JP2007232459A (en) | Optical fiber intrusion monitor | |
JP2005241431A (en) | Optical fiber interference type sensor | |
CN101025845A (en) | Perimeter defense optical fiber sensor | |
KR101698835B1 (en) | Displacement measurement system using optical fiber | |
CN201032465Y (en) | Perimeter defense optical fiber sensor | |
CN203839113U (en) | High-sensitivity fiber stress sensing photoelectric composite cable | |
CN211180318U (en) | Magnetized load-bearing detection optical cable | |
JPH0235323A (en) | Optical fiber temperature sensor | |
CN205861043U (en) | A kind of rock stratum sedimentation protection detection device | |
RU2020131700A (en) | SIGNALING METHOD USING FIBER-OPTIC SECURITY DETECTOR WITH HARDWARE DELAY LINE | |
Wu et al. | Analysis on polarization state of the distributed optical fiber sensor based on Sagnac/Mach-Zehnder interference structure |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: FIBER SENSYS, INC., OREGON Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TAPANES, EDWARD;REEL/FRAME:030421/0677 Effective date: 20101028 |
|
AS | Assignment |
Owner name: FIBER SENSYS, INC., OREGON Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TAPANES, EDWARD;REEL/FRAME:030714/0536 Effective date: 20101028 |
|
AS | Assignment |
Owner name: FIBERSONICS INC., OREGON Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FIBER SENSYS INC;REEL/FRAME:033308/0997 Effective date: 20140613 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |