| Patent Number |
Title Of Patent |
Date Issued |
| H1813 |
Spectrally-selective fiber transmission filter system |
November 2, 1999 |
| An in-line, spectrally-selective fiber Fabry-Perot transmission filter includes an optical fiber piece having a broad-band mirror and a narrow-band Bragg grating element formed therein, the mirror and the grating forming a Fabry-Perot resonant cavity therebetween. The filter may be u |
| H1626 |
Fiber optic network system with low crosstalk using code-division multiplexing |
January 7, 1997 |
| A code-division multiplexed system comprising an optical source, a code generator for developing and applying a pseudo-random bit sequence code to the optical source to cause the optical source to develop a unipolar coded optical signal, a means for dividing the unipolar coded optical si |
| H1436 |
Interferometric fiber optic sensor configuration with pump-induced phase carrier |
May 2, 1995 |
| An interferometric fiber optic sensor and method are provided for controlling the optical phase of a fiber interferometer by an optically induced change in the refractive index for one arm of the fiber interferometer and providing a passive all-optical phase shift interrogation in re |
| 6081633 |
Fiber optic sensor array system with forward coupled topology |
June 27, 2000 |
| A forward-coupled array topology is used for a ladder-type fiber optic ser system in which each optical path in the system includes the same total number of input and output optical fiber sections and approximately the same total number of input and output couplers and splices so that t |
| 5945666 |
Hybrid fiber bragg grating/long period fiber grating sensor for strain/temperature discriminatio |
August 31, 1999 |
| A grating sensor system for simultaneously determining strain and temperature is disclosed, which system comprises: a light source for providing a continuous broadband light; a single mode fiber coupled to the light source; a hybrid fiber grating sensor written into the single mode f |
| 5892860 |
Multi-parameter fiber optic sensor for use in harsh environments |
April 6, 1999 |
| A sensor capable of measuring a number of physical parameters in a harsh environment includes a plurality of intrinsic fiber optic sensor elements formed within a core of an optical fiber, the optical fiber being disposed within a capillary tube made of a high strength, corrosion resista |
| 5818585 |
Fiber Bragg grating interrogation system with adaptive calibration |
October 6, 1998 |
| A system and method for providing accurate measurements of the reflected wavelengths from multiple strings of fiber Bragg grating (FBG) elements using a single scanning optical filter and an isolated duplicate reference string of FBG elements. A reference string of FBG elements permits p |
| 5757487 |
Methods and apparatus for distributed optical fiber sensing of strain or multiple parameters |
May 26, 1998 |
| A distributed optical fiber sensor system including a patterned array of kly reflecting broadband gratings or other sensors serially disposed along a common fiber. The laser sources are multiplexed onto the fiber and are propagated through a directional coupler toward the sensors. The |
| 5748312 |
Sensing apparatus and method for detecting strain between fiber bragg grating sensors inscribed |
May 5, 1998 |
| A sensing apparatus and related method for sensing strain between fiber Bragg grating sensors inscribed in an optical fiber. The fiber is inscribed with a first fiber Bragg grating sensor and a second fiber Bragg grating sensor. A strain detection unit detects strain between the first |
| 5706079 |
Ultra-high sensitivity transducer with chirped bragg grating relector |
January 6, 1998 |
| A transducer and measurement system includes a fiber Bragg grating which a regular variation of spacing of partially reflecting surfaces, known as a chirp, either formed or induced therein and which is capable of reflecting energy having a predetermined wavelength. When the fiber Bragg |
| 5680489 |
Optical sensor system utilizing bragg grating sensors |
October 21, 1997 |
| An optical system for detecting perturbations indicative of the performance f the piece of equipment being monitored is disclosed. The optical system comprises sensors each of which use Bragg gratings induced therein and wherein the Bragg gratings are arranged into a preselected distribut |
| 5528367 |
In-line fiber etalon strain sensor |
June 18, 1996 |
| An in-line fiber etalon strain sensor, and method for making the sensor, is disclosed. The in-line fiber etalon strain sensor uses a short segment of silica hollow-core fiber spliced between two cleaved sections of single-mode fiber to form a mechanically robust in-line cavity. In making |
| 5495366 |
Apparatus and method for eliminating polarization sensitivity in transducers |
February 27, 1996 |
| An apparatus and method for converting a signal of arbitrary polarization one of preselected polarization, e.g. for use by a sensor, transducer, etc. A signal splitter divides the input signal into its orthogonal linearly polarized components, and launches the components from a pair of |
| 5488475 |
Active fiber cavity strain sensor with temperature independence |
January 30, 1996 |
| A strain sensor system formed from a laser cavity where changes in length of the cavity are used to measure strain. The cavity can include a passive optical fiber strain sensing section and/or an active doped optical fiber section that lases when pumped by a laser pump. The cavity can be |
| 5479094 |
Polarization insensitive current and magnetic field optic sensor |
December 26, 1995 |
| A sensor system includes a sensor head, an optical source, and a measurement apparatus. The sensor head includes a beamsplitter having first, second, third, and fourth ports, the beamsplitter being responsive to light selectively applied to the first, second and third ports for passi |
| 5434501 |
Polarization insensitive current and magnetic field optic sensor |
July 18, 1995 |
| A sensor system includes a sensor head, an optical source, and a measurement apparatus. The sensor head includes a beamsplitter having first, second, third, and fourth ports, the beamsplitter being responsive to light selectively applied to the first, second and third ports for passi |
| 5410404 |
Fiber grating-based detection system for wavelength encoded fiber sensors |
April 25, 1995 |
| An apparatus for the determination of the wavelength and the detection of velength shifts in wavelength-encoded fiber sensors, such as Bragg grating sensors. The apparatus is implemented in fiber and uses a pair of tuned fiber gratings to provide a filter type function that tracks the |
| 5361130 |
Fiber grating-based sensing system with interferometric wavelength-shift detection |
November 1, 1994 |
| A system for sensing a measurand field, the system comprising a source of broadband light, a sensor, an unbalanced optical interferometric apparatus, and a signal processor. The sensor produces an optical return signal having a wavelength functionally dependent on the measurand field. |
