基于单通带微波光子滤波器的光纤温度传感器

In this paper, a sensing interrogation system for fiber-optic interferometer type of sensors by using a single-passband radio-frequency (RF) filter has been proposed and experimentally demonstrated. The fiber-optic interferometer based sensor can give continuous optical sampling, and along with dispersive medium a single-passband RF frequency response can be achieved. The sensing parameter variation on the fiber-optic interferometer sensor will affect its free spectrum range, and thus the peak frequency of the RF filter. By tracking the central frequency of the passband the sensing parameter can be demodulated. As a demonstration, in our experiment a fiber Mach-Zehnder interferometer (FMZI) based temperature sensor has been interrogated. By tracking the peak frequency of the passband the temperature variation can be monitored. In our experiment, the sensing responsivity of 73.9 MHz/℃, 53.6 MHz/℃ and 42.5 MHz/℃, when the lengths of sensing fiber are 2 m, 1 m and 0.5 m have been achieved.