A fiber Fabry-Perot interferometric (FFPI) temperature sensor system with digital signal processing scheme is introduced. Major functions of this digital processor is to determine the difference between the round trip optical phase shift of the sensor and reference FFPIs as changes occur in the temperature at the sensor location. The interference fringe shift caused by thermally induced chirping of laser diode light source is utilized in this scheme. The system is developed as a stand-alone instrument which has its own LCD display and a control keyboard.
Y. Yeh, Y. Yeh,
"In-line Fabry-Perot interferometric temperature sensor with digital signal processing", Proc. SPIE 1584, Fiber Optic and Laser Sensors IX, (1 December 1991); doi: 10.1117/12.2321951; https://doi.org/10.1117/12.2321951