Optical fiber Fabry-Perot sensors

A new optical fiber Fabry-Perot (F.P.) temperature sensor is proposed and demonstrated. In particular, it can discern the temperature rise from the temperature drop. With this sensor, the temperature change and the direction of temperature change can be determined as a function of time. The basic concept has been verified experimentally. The results of fiber F.P. sensor measurement compare well with an independent thermocouple measurement. To provide further insight, details of the experimentally observed interference fringes have also been compared to a computer simulation. Possible real-time implementations with highspeed electronics are suggested.