Open loop signal processing circuit and method for a fiber optic interferometric sensor
Abstract
A signal processing circuit (10) for a fiber optic sensor (12) includes a d.c. block (14) coupled to the fiber optic sensor (12) for removing d.c. components from the fiber optic sensor output signal, and a low pass filter (16) coupled to the d.c. block (14) for reducing noise in the fiber optic sensor output signal and generate a filtered signal. A comparator (18) is coupled to the low pass filter (16) and generates a squared signal indicative of zero crossings in the filtered signal. A lock-in amplifier or synchronous demodulator (20) is coupled to the comparator (18) and generates an output signal indicative of a phase shift in the two light waves propagating in the fiber optic sensor (12).
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Citation
Blake, James N. (1999). Open loop signal processing circuit and method for a fiber optic interferometric sensor. United States. Patent and Trademark Office; Texas A&M University. Libraries. Available electronically from https : / /hdl .handle .net /1969 .1 /176622.