A Method for Controlling Sensitivity of Fabry–Perot Interferometer Sensors Based on Vernier Effect

Optical fiber cascaded Fabry–Perot interferometers temperature sensors based on Vernier effect are studied in detail by theoretical simulation. The simulation results show that the free spectrum range (FSR) difference of the two Fabry–Perot interferometers affects the temperature sensitivity. When the value of the FSR difference is positive, the temperature sensitivity is positive too. Otherwise, the temperature sensitivity is negative. Furthermore, the temperature sensitivity of the Fabry–Perot interferometer sensors based on Vernier effect is higher with the FSR difference smaller. Therefore, we propose a method for controlling the sensitivity of the Fabry–Perot interferometer sensors based on Vernier effect by adjusting the difference of the two FSR.