Patent ID: 6901176
Filing Date: 2005-05-31
Classification: G01D,G01H,G02B

Abstract:
1. A fiber optic sensor system for acoustic measurements, comprising: at least one sensor, said at least one sensor including a diaphragm and a sensing fiber-tip based interferometer having a Fabry-Perot cavity formed between said fiber tip and said diaphragm, said fiber tip and said diaphragm both being optically reflective to form a pair of reflective surfaces of said interferometer; an Integrated Optical Circuit phase modulator coupled to said at least one sensor, a read-out interferometer built in said Integrated Optical Circuit phase modulator, said read-out interferometer being path-matched to said sensing interferometer, a source of light generating a light beam coupled to said Integrated Optical Circuit phase modulator for being modulated therein, the modulated light being coupled to said at least one sensor, at least one photo-detector coupled to an output of said at least one sensor and to said Integrated Optical Circuit phase modulator, and processing means for calculating the phase signal of said at least one sensor, said processing means including phase modulating means and phase demodulating means, said phase modulating means being coupled to said Integrated Optical Circuit phase modulator to define a phase modulation pattern thereof, and said phase demodulating means being coupled to an output of said at least one photodetector to decode the optical intensity of the signal output therefrom.