Dynamic Demodulation Method for Fabry-Perot Sensors Based on the Double-Sideband Microwave Modulation

The development of high-speed dynamic demodulation methods for dynamic Fabry-Perot sensors is essential for high-speed measurements. A new double-sideband microwave modulation demodulation algorithm is proposed. After microwave signal modulation, the envelope of the double-sideband signal generated by dynamic Fabry-Perot interferometry contains dynamic interference phase information. By combining the dynamic interference phase information within the envelope with arctangent operation, high-speed dynamic demodulation of the dynamic cavity length can be achieved. Experimental results demonstrate that the dynamic cavity length demodulation rate can reach up to 10.2 MHz, and it is capable of demodulating the resonant cavity length of a pressure Fabry-Perot sensor at a frequency of 332 kHz in shock wave pressure measurement experiments.