| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 356483000 | Plural counter-propagating beams (e.g., non-motion Sagnac device) | 13 |
| 20080291462 | APPARATUS AND METHOD FOR USING A COUNTER-PROPAGATING SIGNAL METHOD FOR LOCATING EVENTS - An apparatus and method for using a counter-propagating signal method for locating events is disclosed. The apparatus and method uses a Mach Zehnder interferometer through which counter-propagating signals can be launched. If the sensing zone of the Mach Zehnder interferometer is disturbed, modified counter-propagating signals are produced, and the time difference between receipt of those signals is used to determine the location of the event. Polarisation controllers receive feedback signals so that the polarisation states of the counter-propagating signals can be controlled to match the amplitude and/or phase of the signals. Detectors are provided for detecting the modified signals. | 11-27-2008 |
| 20080297805 | Spectral balancing system and method for reducing noise in fiber optic gyroscopes - Methods and apparatus are provided for reducing output noise of optical gyros. The apparatus includes a sensing system for circulating counter-propagating light beams and producing an output light beam, a coupler having multiple ports and supplying an input light beam to the sensing system, a first detector coupled to the coupler for detecting a rotation rate based on the output light beam, a second detector coupled to the coupler for detecting noise based on the input light beam, and at least one optical device coupled to one of the ports of the coupler. The optical device is configured to reduce a spectral mismatch between the input light beam received by the second detector and the output light beam received by the first detector. | 12-04-2008 |
| 20090185192 | APPARATUS AND METHOD FOR USING A COUNTER-PROPAGATING SIGNAL METHOD FOR LOCATING EVENTS - An apparatus and method for using a counter-propagating signal method for locating events is disclosed. The apparatus and method uses a Mach Zehnder interferometer through which counter-propagating signals can be launched. If the sensing zone of the Mach Zehnder interferometer is disturbed, modified counter-propagating signals are produced and the time difference between receipt of those signals is used to determine the location of the event. A microcontroller receives feedback signals which adjusts polarisation controllers so that the polarisation states of the counter-propagating signals can be controlled to match the amplitude and/or phase of the output signals. Detectors are provided for detecting the modified signals. | 07-23-2009 |
| 20090290165 | OPTICAL HIGH VOLTAGE SENSOR - An electro-optical high-voltage sensor includes a waveguiding sensing fiber of an electro-optical material. The electrical field of the voltage to be measured is substantially parallel to the longitudinal axis of the sensing fiber. The sensing fiber carries two orthogonally polarized light waves, with the applied field affecting the birefringence between the waves. Using an electro-optical waveguiding fiber in this configuration allows the voltage between two widely spaced points to be accurately measured. | 11-26-2009 |
| 20100014095 | DETECTION AND LOCATION OF BOUNDARY INTRUSION, USING COMPOSITE VARIABLES DERIVED FROM PHASE MEASUREMENTS - A disturbance, such as vibration from human activity, is located along a fiberoptic waveguide configuration ( | 01-21-2010 |
| 20100141955 | Sensor probe for fiber-based current sensor - Embodiments of the present invention provide a sensor probe for fiber-based electric current sensors. The sensor probe includes a conductor of spiral shape and a relatively straight optical fiber being placed at a through-hole formed by the spiral shape conductor. An electric current conveyed by the spiral shape conductor causes polarization direction of a light traveling along the optical fiber to rotate. By detecting the amount of rotation that the light experiences at the ends of the optical fiber, the amount of current carried by the spiral shape conductor is determined. Method of making the sensor probe is also disclosed. | 06-10-2010 |
| 20110116099 | APPARATUS AND METHOD FOR DETECTING PRESSURE SIGNALS - An apparatus for detecting data in a fluid pressure signal in a conduit comprises an optical fiber loop comprises a measurement section and a delay section wherein the measurement section is disposed substantially circumferentially around at least a portion of the conduit, and wherein the measurement section changes length in response to the fluid pressure signal in the conduit. A light source injects a first optical signal in a first direction into the measurement section and a second optical signal in a second direction opposite the first direction into the delay section. An optical detector senses an interference phase shift between the first optical signal and the second optical signal and outputs a first signal related thereto. | 05-19-2011 |
| 20110141478 | SAGNAC INTERFEROMETER-TYPE FIBER-OPTIC CURRENT SENSOR - In one embodiment, a Sagnac interferometer-type fiber-optic sensor includes a synchronous detection circuit to carry out synchronous detection of detected light signal with a phase modulation angular frequency of a phase modulator. A signal processing circuit calculates and outputs the magnitude of current to be measured using the signal detected in the synchronous detection circuit. A phase modulator driving circuit controls the driving of the phase modulator. The phase modulator driving circuit controls a phase modulation depth of the phase modulator so that the amplitude of the second-order harmonics and the fourth-order harmonics obtained by carrying out the synchronous detection of the detected light signal with the phase modulation angular frequency becomes the same. | 06-16-2011 |
| 20120062902 | FIBER OPTIC SENSOR USING A HOLLOW CORE FIBER - An optical sensor includes at least a portion of an optical waveguide having a hollow core generally surrounded by a cladding. The cladding substantially confines a first optical signal and a second optical signal within the hollow core as the first optical signal and the second optical signal counterpropagate through the optical waveguide. Interference between the first optical signal and the second optical signal is responsive to perturbation of the at least a portion of the optical waveguide. | 03-15-2012 |
| 20140340690 | GUIDED OPTICAL ROUTER, FIBRE-OPTIC INTERFEROMETER INTEGRATING SUCH AN OPTICAL ROUTER AND METHOD OF GUIDED OPTICAL ROUTING - A bidirectional guided optical router includes an evanescent-field optical coupler having three input ports, three output ports, a first central waveguide, a second lateral waveguide and a third lateral waveguide and an evanescent-field-based optical coupling zone in which the first, second and third waveguides are disposed so as to allow evanescent-field-based coupling between the first central waveguide and either one of the lateral waveguides. The 3×3 optical coupler has a length L of between 3154×L | 11-20-2014 |
| 20140347671 | SAGNAC INTERFEROMETER-TYPE FIBER-OPTIC CURRENT SENSOR - In one embodiment, a Sagnac interferometer-type fiber-optic sensor includes a synchronous detection circuit to carry out synchronous detection of detected light signal with a phase modulation angular frequency of a phase modulator. A signal processing circuit calculates and outputs the magnitude of current to be measured using the signal detected in the synchronous detection circuit. A phase modulator driving circuit controls the driving of the phase modulator. The phase modulator driving circuit controls a phase modulation depth of the phase modulator so that the amplitude of the second-order harmonics and the fourth-order harmonics obtained by carrying out the synchronous detection of the detected light signal with the phase modulation angular frequency becomes the same. | 11-27-2014 |
| 20150300804 | 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. | 10-22-2015 |
| 20160040530 | HIGH DATA-RATE TELEMETRY PULSE DETECTION WITH A SAGNAC INTERFEROMETER - An example telemetry signal detection apparatus may include a optical splitter, a light source optically coupled to the optical splitter, and a light detector optically coupled to the optical splitter. The apparatus further may include a reference loop optically coupled to the optical splitter and a sensor loop optically coupled to the reference loop and the optical splitter. The reference loop may be contained within a reference loop enclosure. The sensor loop and reference loop may comprise a zero-area Sagnac loop with folded optical fiber or dual fiber cable configurations. | 02-11-2016 |
