Abstract: Optical sensor measurement methods that convert a wavelength change in an optical sensor to a measurable optical intensity change, which can be calibrated and used to measure optical wavelength change and environmental changes such as temperature or strain which affect sensor wavelength. The current invention makes use of tunable fiber Fabry-Perot filters as the wavelength selective elements for the wavelength to optical intensity conversion. The invention provides high measurement sensitivities to small amplitude, high frequency modulations to the fiber sensor center wavelength, accommodates for system drift from thermal or other perturbations, and enables either frequency mode or time varying resolution of sensor modulation events. Selection of proper Fabry-Perot optics allow for measurement optimization of either high sensitivity or high strain measurement range.

Abstract: A method for calibrating tunable optical filters, calibrated tunable filters and devices employing such filters. The method is of particular use with fiber Fabry-Perot tunable filters and more particularly for filters which employ piezoelectric transducers as tuning elements. Sets of calibration coefficients are generated which span the wavelength region and operating temperature range of the filter. Calibrated tunable filters are combined with a means for storing the sets of calibration coefficients and means for correcting wavelength measurements using the sets of coefficients in devices which measure wavelengths of light. The sets of calibration coefficients can also be used to tune the filter to pass a selected wavelength of interest.