Patent ID: 7038786

Claim:
An optical interferometric sensor for providing an output signal indicative of a measureand intended to be sensed, the optical sensor comprising: an optical interferometer, including first and second light waves that travel along a selected optical path established by selected optical components, where, said first and second light waves aligned in such a manner so as to permit the first and second light waves to interfere with each other at a first spatial location, at least a portion of the defined optical path is configured such that a phase shift is induced between the first and second light waves in response to a measureand, and at least one photodetector responsive to at least a portion of the sum of said first and second light waves impinging thereon, and providing a detector signal indicative of said sum; first signal processing means responsive to said detector signal for providing a visibility signal indicative of the visibility parameter of the interferometer, and wherein said visibility signal is a function of the temperature of said optical components that define said defined optical path, and also indicative of the long term life performance of said optical components; second signal processing means responsive to said detector signal and said visibility signal for providing a first output signal indicative of said induced phase shift in response to the measurand intended to be measured; and third signal processing means responsive to said first output signal and said visibility signal for providing a second output signal indicative of said induced phase shift in response to the measurand including error compensation induced by temperature and long term life performance changes in said a optical components.