With the recent, rapid acceleration in the growth of fiber optic transmission systems, it seems logical that all-optical sensors will be the next generation of sensors--not just for temperature and pressure but for a variety of parameters, including stress, displacement, liquid level, etc. To demonstrate the optical sensor concept, a presure sensor will be designed and fabricated for application in the emp/emi, high-temperature conditions of turbine engine test instrumentation. The sensor consists of a broadband light source coupled into an optical fiber which transmits this broadband spectrum to the remote sensor element. The sensor element is a variable gap fabryperot cavity which modulates the reflected spectrum according to gap dimension. The reflected spectrum is fiber-transmitted back to a microprocessor based, color demodulation system. This color demodula-tion is accomplished by prism dispersion over a charge-coupled-device (ccd). The microprocessor uses kalman filtering to analyze and convert the spectral data to pressure.
