Title:
OPTICAL INTERFEROMETRIC SENSOR WITH OPTICAL ERROR COMPENSATION
Document Type and Number:
WIPO Patent Application WO2003034009
Kind Code:
A3
Abstract:
In accordance with the present invention, an optical interferometer employed as a current sensor is provided with visibility compensation and scale factor compensation. At least one photodetector (846) is responsive to at least a portion of the sum of the pair of optical beams and provide a beam output signal indicate thereof. From the beam output signal, a first signal is derived that is indicative of the visibility of the interferometer. A signal processor (350) derives from the beam output signal an output signal indicative of the bias point of the interferometer, where the bias point is indicative of the induced phase shift in response to the measureand. A compensated interferometer output signal indicative of the induced phase shift is derived as a function of the visibility signal and bias point signal. In a specific embodiment of the invention, the visibility signal may simply be the output of a signal averaging circuit which in turn may adjust the gain of the signal processing circuit.
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Inventors:
BLAKE JAMES N (US)
Application Number:
PCT/US2002/032880
Publication Date:
December 11, 2003
Filing Date:
October 15, 2002
Export Citation:
Assignee:
BLAKE JAMES N (US)
International Classes:
G01B9/02; G01D5/353; (IPC1-7): G01J4/04; G01D5/26; G01R15/24
Foreign References:
| US6046810A | 2000-04-04 | |||
| US5696858A | 1997-12-09 | |||
| US5811964A | 1998-09-22 |
Other References:
PATENT ABSTRACTS OF JAPAN vol. 007, no. 032 (P - 174) 8 February 1983 (1983-02-08)
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