Optics: measuring and testing – By particle light scattering – With photocell detection
Patent
1987-06-25
1988-10-25
McGraw, Vincent P.
Optics: measuring and testing
By particle light scattering
With photocell detection
250227, 356350, G01B 902, G01C 1964
Patent
active
047799757
ABSTRACT:
An interferometer used as a rotation sensor is constructed using a strand of optical fiber, a portion of which is formed into a sensing loop. A pair of light waves are caused to counterpropagate in the sensing loop and are combined to form an optical output signal that has an intensity that varies in accordance with the difference in the phases of the two counterpropagating light waves. A phase modulator is positioned on the optical fiber in the sensing loop at a location such that the two counterpropagating light waves are modulated approximately 180 degrees out of phase. The time-varying phase modulation causes a time-varying phase difference that is combined with a rotationally-induced Sagnac effect phase to provide a total phase difference that is detected by a photodetector. The photodetector provides an electrical output signal this is differentiated to provide a differentiated output signal that has zero-crossings that correspond to maxima and minima of the electrical output signal. The time intervals between selected zero-crossings are measured and the rotationally-induced phase difference caused by the Sagnac effect is calculated from the measured time intervals. The rotation rate is then calculated from the Sagnac phase difference.
REFERENCES:
patent: 4299490 (1981-11-01), Cahill et al.
patent: 4372685 (1983-02-01), Ulrich
patent: 4386822 (1983-06-01), Bergh
patent: 4456377 (1984-07-01), Shaw et al.
patent: 4469397 (1984-09-01), Shaw et al.
patent: 4493528 (1985-01-01), Shaw et al.
patent: 4529312 (1985-07-01), Pavlath et al.
patent: 4536058 (1985-08-01), Shaw et al.
patent: 4556321 (1985-12-01), Schiffner
patent: 4564293 (1986-01-01), Newton et al.
patent: 4634282 (1987-01-01), Shaw et al.
patent: 4634852 (1987-01-01), Shaw
patent: 4637722 (1987-01-01), Kim
patent: 4671658 (1987-06-01), Shaw et al.
patent: 4687330 (1987-08-01), Lefevre
patent: 4697926 (1987-10-01), Youngquist et al.
patent: 4699513 (1987-10-01), Brooks et al.
Martin et al., "Fiber Optic Laser Gyro Signal Detection and Processing Technique," SPIE, vol. 139, 1978, pp. 98-102.
J. L. Davis et al., "Techniques for Shot Noise Limited Inertial Rotation Measurement Using a Multiturn Fiber Sagnac Interferometer," SPIE, vol. 157, 1978, pp. 131-136.
M. R. Layton et al., "Optical Fiber Acoustic Sensor Utilizing Mode--Mode Interference," Applied Optics, vol. 18, No. 5, Mar. 1, 1979, pp. 666-670.
J. L. Davis et al., "Closed-Loop Low-Noise Fiber-Optic Rotation Sensor," Optics Letters, vol. 6, No. 10, Oct. 1981, pp. 505-507.
Thomas G. Giallorenzi et al., "Optical Fiber Sensor Technology," IEEE Journal of Quantum Electronics, vol. QE-18, No. 4, Apr. 1982, pp. 626-665.
H. Lefevre, "Contribution a la Gyrometrie a Fibre Optique de Classe Inertielle," Thesis Presentation at the University of Nice, July 1, 1982, Section C-III.3, pp. 187-189.
Toshihiko Yoshino et al., "Fiber-Optic Fabry-Perot Interferometer and Its Sensor Applications," IEEE Journal of Quantum Electronics, vol. QE-18, No. 10, Oct. 1982, pp. 1624-1633.
I. P. Giles et al., "Coherent Optical-Fiber Sensors with Modulated Laser Sources," Electronics Letters, vol. 19, No. 1, Jan. 6, 1983, pp. 14-15.
G. Meltz et al., "Cross-Talk Fiber-Optic Temperature Sensor," Applied Optics, vol. 22, No. 3, Feb. 1, 1983, pp. 464-477.
B. Y. Kim et al., "Harmonic Feed-Back Approach to Fiber Gyroscale Factor Stabilization," International Conference on Optical Fibre Sensors, London, Apr. 26-28, 1983 (2 pp.).
Ralph A. Bergh et al., "An Overview of Fiber-Optic Gyroscopes," Journal of Lightwave Technology, vol. LT-2, No. 2, Apr. 1984, pp. 91-107.
B. Y. Kim et al., "All-Fiber-Optic Gyroscope with Linear Scale Factor Using Phase Detection," SPIE, vol. 478, pp. 142-148.
B. Y. Kim et al., "Gated Phase-Modulation Feedback Approach to Fiber-Optic Gyroscopes," Optics Letters, vol. 9, No. 6, Jun. 1984, pp. 263-265.
B. Y. Kim et al., "Gated Phase-Modulation Approach to Fiber-Optic Gyroscope with Linearized Scale Factor," Optics Letters, vol. 9, No. 8, Aug. 1984, pp. 375-377.
B. Y. Kim et al., "Phase-Reading, All-Fiber-Optic Gyroscope," Optics Letters, vol. 9, No. 8, Aug. 1984, pp. 378-380.
B. Yoon Kim et al., "Fiber-Optic Gyroscopes," IEEE Spectrum, Mar. 1986, pp. 56-60.
H. C. Lefevre et al., "Progress in Optical Fiber Gyroscopes Using Integrated Optics," 37th Meeting/Specialists' Meeting of the Electromagnetic Wave Propagation Panel on Guided Optical Structures in the Military Environment, Istanbul, Turkey, Sep. 23-27, 1985, pp. 1-12.
Kim, "All-Fiber-Optic Gyroscope with Extended Linear Dynamic Range," Report #0888, Edward L. Linzton Lab., W. W. Hanson Laboratories of Physics, Stanford University, Jun. 1985.
McGraw Vincent P.
The Board of Trustees of the Leland Stanford Junior University
LandOfFree
Interferometric sensor using time domain measurements does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Interferometric sensor using time domain measurements, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Interferometric sensor using time domain measurements will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2266176