An optical displacement sensor is disclosed that provides a high signal-to-noise ratio output signal without some of the disadvantages for doing so in the prior art. An embodiment of the present invention directs a light beam toward a Fabry-Perot interferometer and detects both the reflected and transmitted optical beams that result from interaction with the Fabry-Perot interferometer. Signal processing techniques are applied to signals based on both the reflected and transmitted beams, resulting in higher signal strength and/or reduced noise in the resulting output signal.
An optical displacement sensor is disclosed that provides a optical displacement sensor that includes a optically-resonant cavity tuned to an operating wavelength without some of the disadvantages for doing so in the prior art. An embodiment of the present invention tunes an operating wavelength used with a Fabry-Perot interferometer to develop a desired relationship between the wavelength and the Fabry-Perot interferometer's initial cavity length.
An optical displacement sensor for sensing an environmental stimulus is disclosed. The optical displacement sensor exhibits an optical design that has suppressed back reflection and improved alignment tolerance between its optical components. The sensor is based on an optically resonant cavity whose cavity length is affected by the environmental stimulus. An embodiment of the present invention utilizes a lens to redirect a first light signal toward an optically resonant cavity such that the light is incident on the cavity at a non-normal angle of incidence.
