Integrated optical micromachined pressure sensor with spectrally encoded output and temperature compensation

A promising type of optical pressure sensor combines an integrated optical interferometer with a micromachined diaphragm on a shared silicon substrate. We have demonstrated a sensor of this type that uses an unbalanced Mach-Zehnder waveguide interferometer together with a broadband source to produce a spectrally encoded measurement. This spectral encoding mechanism is advantageous as it is not readily degraded by transmission through optical fibers. We have also demonstrated a means to obtain a temperature-compensated pressure measurement by interrogating both polarization eigenmodes of the interferometer.