Fabry-Perot readout technique using wavelength tuning

Abstract

A method for sensing an environmental parameter includes the step of sensing the environmental parameter with an interferometer sensor that has a light source emitting a tunable wavelength of light and a gap that changes in length in response to the environmental parameter. The interferometer has a sinusoidal output curve that oscillates in intensity in response to changes in gap length. The wavelength of light emitted by the light source is tuned to a first wavelength to provide a first output value. Similarly, the wavelength of light emitted by the light source is next tuned to a second wavelength to provide a second output value. The first and second output values correspond to points on the sinusoidal output curve that differ by at least half a cycle. The gap length is then calculated from the values of the first wavelength and the difference between the first and second wavelengths. Finally, the value of the environmental parameter is determined from the value of the gap length.

Dependencies are inferred from the claim text.