A personnel monitoring system. The personnel monitoring system includes a host node having an optical source for generating optical signals, and an optical receiver. The personnel monitoring system also includes a plurality of fiber optic sensors for converting at least one of vibrational and acoustical energy to optical intensity information, each of the fiber optic sensors having: (1) at least one length of optical fiber configured to sense at least one of vibrational and acoustical energy; (2) a reflector at an end of the at least one length of optical fiber; and (3) a field node for receiving optical signals from the host node, the field node transmitting optical signals along the at least one length of optical fiber, receiving optical signals back from the at least one length of optical fiber, and transmitting optical signals to the optical receiver of the host node.
G01N 21/84 - Systems specially adapted for particular applications
G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
G01B 11/16 - Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
G01S 1/72 - Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmittersReceivers co-operating therewith using ultrasonic, sonic, or infrasonic waves
G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans 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 convertingTransducers not specially adapted for a specific variable using optical 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
H04Q 9/00 - Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom
H04R 23/00 - Transducers other than those covered by groups
G08G 1/04 - Detecting movement of traffic to be counted or controlled using optical or ultrasonic detectors
2.
Damped fiber optic accelerometers, sensors, and sensor assemblies, and methods of assembling the same
A fiber optic sensor is provided. The fiber optic sensor includes: a fixed portion configured to be secured to a body of interest; a moveable portion; a spring member positioned at least partially between the fixed portion and the moveable portion; an optical fiber wound in contact with the fixed portion and the moveable portion such that the optical fiber spans at least a portion of the spring; and an elastomeric material provided in contact with at least one of the fixed portion, the moveable portion, the spring member, the body of interest, and the optical fiber.
G01P 15/093 - Measuring accelerationMeasuring decelerationMeasuring shock, i.e. sudden change of acceleration by making use of inertia forces with conversion into electric or magnetic values by photoelectric pick-up
G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans 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 convertingTransducers not specially adapted for a specific variable using optical 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
G01D 5/26 - Mechanical means for transferring the output of a sensing memberMeans 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 convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light
F16F 9/32 - Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium Details
F16F 9/00 - Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
G01P 15/08 - Measuring accelerationMeasuring decelerationMeasuring shock, i.e. sudden change of acceleration by making use of inertia forces with conversion into electric or magnetic values
3.
Fiber optic transducers, fiber optic accelerometers and fiber optic sensing systems
A fiber optic transducer is provided. The fiber optic transducer includes a fixed portion configured to be secured to a body of interest, a moveable portion having a range of motion with respect to the fixed portion, a spring positioned between the fixed portion and the moveable portion, and a length of fiber wound between the fixed portion and the moveable portion. The length of fiber spans the spring. The fiber optic transducer also includes a mass engaged with the moveable portion. In one disclosed aspect of the transducer, the mass envelopes the moveable portion.
G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans 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 convertingTransducers not specially adapted for a specific variable using optical 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
G01L 1/24 - Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis
G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
G01V 1/18 - Receiving elements, e.g. seismometer, geophone
G01P 15/093 - Measuring accelerationMeasuring decelerationMeasuring shock, i.e. sudden change of acceleration by making use of inertia forces with conversion into electric or magnetic values by photoelectric pick-up
4.
Fiber optic backscatter sensing systems and methods of operating the same
A fiber optic sensing system is provided. The fiber optic sensing system includes: at least one fiber optic transducer; an optical backscatter interrogator for interrogating backscatter optical signals from the at least one fiber optic transducer; and an optical fiber between the optical backscatter interrogator and the at least one fiber optic transducer.
G01S 7/481 - Constructional features, e.g. arrangements of optical elements
G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans 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 convertingTransducers not specially adapted for a specific variable using optical 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
5.
Damped fiber optic accelerometers, sensors, and sensor assemblies, and methods of assembling the same
A fiber optic sensor is provided. The fiber optic sensor includes: a fixed portion configured to be secured to a body of interest; a moveable portion; a spring member positioned at least partially between the fixed portion and the moveable portion; an optical fiber wound in contact with the fixed portion and the moveable portion such that the optical fiber spans at least a portion of the spring; and an elastomeric material provided in contact with at least one of the fixed portion, the moveable portion, the spring member, the body of interest, and the optical fiber.
G01P 15/093 - Measuring accelerationMeasuring decelerationMeasuring shock, i.e. sudden change of acceleration by making use of inertia forces with conversion into electric or magnetic values by photoelectric pick-up
G01P 15/08 - Measuring accelerationMeasuring decelerationMeasuring shock, i.e. sudden change of acceleration by making use of inertia forces with conversion into electric or magnetic values
6.
Optical detection systems and methods of using the same
An optical detection system. The optical detection system includes a host node having (a) an optical source for generating optical signals, and (b) an optical receiver. The optical detection system also includes a plurality of fiber optic sensors for converting at least one of vibrational and acoustical energy to optical intensity information, each of the fiber optic sensors having: (1) at least one length of optical fiber configured to sense at least one of vibrational and acoustical energy; (2) a reflector at an end of the at least one length of optical fiber; and (3) a field node for receiving optical signals from the host node, the field node transmitting optical signals along the at least one length of optical fiber, receiving optical signals back from the at least one length of optical fiber, and transmitting optical signals to the optical receiver of the host node.
G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans 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 convertingTransducers not specially adapted for a specific variable using optical 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
G01B 11/16 - Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
G01V 1/22 - Transmitting seismic signals to recording or processing apparatus
G01V 8/24 - Detecting, e.g. by using light barriers using multiple transmitters or receivers using optical fibres
G01V 8/10 - Detecting, e.g. by using light barriers
7.
Fiber optic transducers, fiber optic accelerometers and fiber optic sensing systems
A fiber optic transducer is provided. The fiber optic transducer includes a fixed portion configured to be secured to a body of interest, a moveable portion having a range of motion with respect to the fixed portion, a spring positioned between the fixed portion and the moveable portion, and a length of fiber wound between the fixed portion and the moveable portion. The length of fiber spans the spring. The fiber optic transducer also includes a mass engaged with the moveable portion. In one disclosed aspect of the transducer, the mass envelopes the moveable portion.
G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans 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 convertingTransducers not specially adapted for a specific variable using optical 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
G01L 1/24 - Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis
G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
G01V 1/18 - Receiving elements, e.g. seismometer, geophone
G01P 15/093 - Measuring accelerationMeasuring decelerationMeasuring shock, i.e. sudden change of acceleration by making use of inertia forces with conversion into electric or magnetic values by photoelectric pick-up
8.
Fiber optic security systems including a local control node and a remote control unit, and methods of using the same
A fiber optic security system is provided. The fiber optic security system includes at least one length of fiber optic cable affixed to at least one item to be monitored using the fiber optic security system. The fiber optic security system also includes at least one local control node, the at least one local control node including at least one light source for generating and transmitting light through the at least one length of fiber optic cable, and the at least one local control node monitoring a status of the light. The fiber optic security system also includes a remote control unit for receiving information from the at least one local control node regarding the status of the light.
A personnel monitoring system. The personnel monitoring system includes a host node having an optical source for generating optical signals, and an optical receiver. The personnel monitoring system also includes a plurality of fiber optic sensors for converting at least one of vibrational and acoustical energy to optical intensity information, each of the fiber optic sensors having: (1) at least one length of optical fiber configured to sense at least one of vibrational and acoustical energy; (2) a reflector at an end of the at least one length of optical fiber; and (3) a field node for receiving optical signals from the host node, the field node transmitting optical signals along the at least one length of optical fiber, receiving optical signals back from the at least one length of optical fiber, and transmitting optical signals to the optical receiver of the host node.
H04B 10/08 - Equipment for monitoring, testing or fault measuring
G01S 1/72 - Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmittersReceivers co-operating therewith using ultrasonic, sonic, or infrasonic waves
G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans 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 convertingTransducers not specially adapted for a specific variable using optical 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
G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
H04Q 9/00 - Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom
H04R 23/00 - Transducers other than those covered by groups
G08G 1/04 - Detecting movement of traffic to be counted or controlled using optical or ultrasonic detectors
10.
Remotely actuated clamping devices for borehole seismic sensing systems and methods of operating the same
A remotely actuated clamping device for a borehole seismic sensing system. The remotely actuated clamping device includes a clamping mechanism configured to engage a surface of a borehole by actuation of the clamping mechanism. The remotely actuated clamping device also includes a fluid based actuator configured to actuate the clamping mechanism. The fluid based actuator includes a chamber configured to be kept at a pressure that is isolated from an ambient pressure of the borehole. The fluid based actuator also includes a piston within the chamber. The chamber receives a pressurized fluid to move the piston within the chamber to actuate the clamping mechanism. The pressure used to actuate the clamping mechanism is independent of the ambient pressure of the borehole. Also disclosed are methods of operating the device.
E21B 23/04 - Apparatus for displacing, setting, locking, releasing or removing tools, packers or the like in boreholes or wells operated by fluid means, e.g. actuated by explosion
E21B 23/01 - Apparatus for displacing, setting, locking, releasing or removing tools, packers or the like in boreholes or wells for anchoring the tools or the like
G01V 11/00 - Prospecting or detecting by methods combining techniques covered by two or more of main groups
A light powered communications system. The light powered communications system includes an audio control center having at least one optical source and at least one optical receiver. The light powered communications system also includes a plurality of optically powered remote communication systems located remote from the audio control center, each of the optically powered remote communication systems being configured to receive an optical signal from the audio control center. The light powered communication system also includes at least one length of fiber optic cable between the audio control center and each of the optically powered remote communication systems.
H04B 1/38 - Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
H04B 10/10 - Transmission through free space, e.g. through the atmosphere (H04B 10/22, H04B 10/24, H04B 10/30 take precedence);;
H04M 1/00 - Substation equipment, e.g. for use by subscribers
H04B 10/25 - Arrangements specific to fibre transmission
A retaining clip (4) comprising a substantially planar annular sector portion (14) with a sector angle of over 180° and having a recess (15) at each end of the sector arc. Also, a retaining ring comprising a pair of the retaining clip (13), wherein the recessed ends cooperate such that the pair of clips form a complete annulus. Also, a method of installing a retaining ring in a groove formed in a component, comprising inserting a first retaining clip into the groove in a substantially radial direction from a first side of the groove, an inserting a second retaining clip into the groove in a substantially radial direction from a second side of the groove opposite the first.
F16B 21/18 - Means without screw-thread for preventing relative axial movement of a pin, spigot, shaft, or the like and a member surrounding itStud-and-socket releasable fastenings without screw-thread by separate parts with grooves or notches in the pin or shaft with circlips or like resilient retaining devicesMeans without screw-thread for preventing relative axial movement of a pin, spigot, shaft, or the like and a member surrounding itStud-and-socket releasable fastenings without screw-thread by separate parts with grooves or notches in the pin or shaft Details
An optical detection system. The optical detection system includes a host node having (a) an optical source for generating optical signals, and (b) an optical receiver. The optical detection system also includes a plurality of fiber optic sensors for converting at least one of vibrational and acoustical energy to optical intensity information, each of the fiber optic sensors having: (1) at least one length of optical fiber configured to sense at least one of vibrational and acoustical energy; (2) a reflector at an end of the at least one length of optical fiber; and (3) a field node for receiving optical signals from the host node, the field node transmitting optical signals along the at least one length of optical fiber, receiving optical signals back from the at least one length of optical fiber, and transmitting optical signals to the optical receiver of the host node.
A fiber optic security system is provided. The fiber optic security system includes at least one length of fiber optic cable affixed to at least one item to be monitored using the fiber optic security system. The fiber optic security system also includes at least one local control node, the at least one local control node including at least one light source for generating and transmitting light through the at least one length of fiber optic cable, and the at least one local control node monitoring a status of the light. The fiber optic security system also includes a remote control unit for receiving information from the at least one local control node regarding the status of the light.
An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; and at least one amplifier associated with each optical receiver. The interrogator also includes an analog integrator following the at least one amplifier.
A personnel monitoring system. The personnel monitoring system includes a host node having an optical source for generating optical signals, and an optical receiver. The personnel monitoring system also includes a plurality of fiber optic sensors for converting at least one of vibrational and acoustical energy to optical intensity information, each of the fiber optic sensors having: (1) at least one length of optical fiber configured to sense at least one of vibrational and acoustical energy; (2) a reflector at an end of the at least one length of optical fiber; and (3) a field node for receiving optical signals from the host node, the field node transmitting optical signals along the at least one length of optical fiber, receiving optical signals back from the at least one length of optical fiber, and transmitting optical signals to the optical receiver of the host node.
G01V 8/10 - Detecting, e.g. by using light barriers
G01N 21/84 - Systems specially adapted for particular applications
G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans 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 convertingTransducers not specially adapted for a specific variable using optical 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
G08G 1/04 - Detecting movement of traffic to be counted or controlled using optical or ultrasonic detectors
17.
Fiber optic pipeline monitoring systems and methods of using the same
An optical detection system for monitoring a pipeline. The optical detection system includes a host node in the vicinity of, or remote from, a pipeline to be monitored. The optical detection system includes (a) an optical source for generating optical signals, and (b) an optical receiver. The optical detection system also includes a plurality of fiber optic sensors local to the pipeline for converting at least one of vibrational and acoustical energy to optical intensity information, each of the fiber optic sensors having: (1) at least one length of optical fiber configured to sense at least one of vibrational and acoustical energy; (2) a reflector at an end of the at least one length of optical fiber; and (3) a field node for receiving optical signals from the host node, the field node transmitting optical signals along the at least one length of optical fiber, receiving optical signals back from the at least one length of optical fiber, and transmitting optical signals to the optical receiver of the host node.
A fiber optic transducer is provided. The fiber optic transducer includes a fixed portion configured to be secured to a body of interest, a moveable portion having a range of motion with respect to the fixed portion, a spring positioned between the fixed portion and the moveable portion, and a length of fiber wound between the fixed portion and the moveable portion. The length of fiber spans the spring. The fiber optic transducer also includes a mass engaged with the moveable portion. In one disclosed aspect of the transducer, the mass envelopes the moveable portion.
G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
G01P 15/093 - Measuring accelerationMeasuring decelerationMeasuring shock, i.e. sudden change of acceleration by making use of inertia forces with conversion into electric or magnetic values by photoelectric pick-up
G01V 1/18 - Receiving elements, e.g. seismometer, geophone
G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans 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 convertingTransducers not specially adapted for a specific variable using optical 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
A fiber optic microseismic sensing system is provided. The system includes a plurality of nodes, each of the nodes including a surface portion, an underground portion, and an optical cable extending between the surface portion and the underground portion. The surface portion includes (1) an optical source for transmitting an optical signal along the optical cable to the underground portion, and (2) an optical receiver for receiving a return optical signal propagating along the optical cable from the underground portion. The underground portion includes at least one transducer, each of the at least one transducer including (1) a fixed portion configured to be secured to a body of interest, (2) a moveable portion having a range of motion with respect to the fixed portion, (3) a spring positioned between the fixed portion and the moveable portion, and (4) a mass engaged with the moveable portion. The optical cable includes a length of fiber wound between the fixed portion and the moveable portion of each of the at least one transducer, the length of fiber spanning the spring. In one disclosed aspect of the transducer, the mass envelopes the moveable portion.
G01V 1/18 - Receiving elements, e.g. seismometer, geophone
G01D 5/30 - Mechanical means for transferring the output of a sensing memberMeans 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 convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with deflection of beams of light, e.g. for direct optical indication the beams of light being detected by photocells
G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
G01L 1/24 - Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis
G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans 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 convertingTransducers not specially adapted for a specific variable using optical 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
G01P 15/093 - Measuring accelerationMeasuring decelerationMeasuring shock, i.e. sudden change of acceleration by making use of inertia forces with conversion into electric or magnetic values by photoelectric pick-up
20.
Fiber optic acoustic sensor arrays and systems, and methods of fabricating the same
A fiber optic acoustic sensor system. The fiber optic acoustic sensor system includes an optical source, and a fiber optic acoustic sensor array configured to receive an optical signal from the optical source. The fiber optic acoustic sensor array includes a core, a first polymer layer disposed on the core, an optical fiber wound around the first polymer layer, and a second polymer layer disposed on the first polymer layer such that the optical fiber is between the first polymer layer and the second polymer layer.
G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
G01S 15/88 - Sonar systems specially adapted for specific applications
B29C 70/08 - Fibrous reinforcements only comprising combinations of different forms of fibrous reinforcements incorporated in matrix material, forming one or more layers, with or without non-reinforced layers
G02B 6/00 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings
G01V 1/22 - Transmitting seismic signals to recording or processing apparatus
B29C 70/72 - Encapsulating inserts having non-encapsulated projections, e.g. extremities or terminal portions of electrical components
A retaining clip (4) comprising a substantially planar annular sector portion (14) with a sector angle of over 180 ° and having a recess (15) at each end of the sector arc. Also, a retaining ring comprising a pair of the retaining clip (13), wherein the recessed ends cooperate such that the pair of clips form a complete annulus. Also, a method of installing a retaining ring in a groove formed in a component, comprising inserting a first retaining clip into the groove in a substantially radial direction from a first side of the groove, an inserting a second retaining clip into the groove in a substantially radial direction from a second side of the groove opposite the first.
F16B 21/18 - Means without screw-thread for preventing relative axial movement of a pin, spigot, shaft, or the like and a member surrounding itStud-and-socket releasable fastenings without screw-thread by separate parts with grooves or notches in the pin or shaft with circlips or like resilient retaining devicesMeans without screw-thread for preventing relative axial movement of a pin, spigot, shaft, or the like and a member surrounding itStud-and-socket releasable fastenings without screw-thread by separate parts with grooves or notches in the pin or shaft Details
22.
Interrogator for a plurality of sensor fiber optic gratings including a driver/modulator
An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; and at least one amplifier associated with each optical receiver. The interrogator also includes, alternatively, a driver/modulator for the optical source providing on/off pulses; an analog integrator following the at least one amplifier; or a mechanism compensating for masking of one sensor fiber optic grating by another.
A sensing system configured for use in a borehole. The sensing system includes a body portion and a clamp arm engaged with the body portion. The clamp arm is configured to move between a retracted position and an extended position. The sensing system also includes an energy storage element engaged with the body portion. The energy storage element provides energy to move the clamp arm from the retracted position to the extended position. A method of using the sensing system is also provided.
An optical sensor in which acceleration, acoustic velocity, or displacement (vibration) causes a corresponding shift in the center wavelength of the sensor output. The sensor can be coupled to a high-speed interferometric interrogator through an unbalanced fiber interferometer. The unbalanced interferometer functions to translate optical wavelength shift into phase shift, which is easily demodulated by the interrogator. A method of measuring acceleration uses the sensor.
G01P 15/093 - Measuring accelerationMeasuring decelerationMeasuring shock, i.e. sudden change of acceleration by making use of inertia forces with conversion into electric or magnetic values by photoelectric pick-up
An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; and at least one amplifier associated with each optical receiver. The interrogator also includes, alternatively, a driver/modulator for the optical source providing on/off pulses; an analog integrator following the at least one amplifier; or a mechanism compensating for masking of one sensor fiber optic grating by another.
A fiber optic security system is provided. The fiber optic security system includes at least one length of fiber optic cable affixed to at least one item to be monitored using the fiber optic security system. The fiber optic security system also includes at least one local control node, the at least one local control node including at least one light source for generating and transmitting light through the at least one length of fiber optic cable, and the at least one local control node monitoring a status of the light. The fiber optic security system also includes a remote control unit for receiving information from the at least one local control node regarding the status of the light.
G02B 6/04 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
A sensor apparatus combines an optical sensor in which acceleration, acoustic velocity, or displacement (vibration) causes a corresponding shift in the center wavelength of the sensor output, coupled to a high speed interferometric interrogator, through an unbalanced fiber interferometer. The unbalanced interferometer functions to translate optical wavelength shift into phase shift, which is easily demodulated by the interrogator.
Interrogator for a plurality of sensor fiber optic gratings having at least one filter for converting changes in peak reflection wavelength to changes in intensity
An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; at least one amplifier associated with each optical receiver; and an active closed-loop circuit following the at least one amplifier to provide bias voltage stabilization.
A fiber optic interrogator includes a broadband optical source, at least one beam splitter directing output of the optical source to an array of fiber optic gratings, at least one linear transmission or reflection filter, at least one optical receiver and at least one amplifier associated with each receiver. In one aspect of the invention, a pair of opposite-sloped linear transmission filters are utilized to normalize the received and filtered reflections with respect to total optical power.
patents
