Microwave photonic filter assistant Vernier microwave frequency comb based fiber sensor

A novel fiber optic sensor based on detecting the envelope of a Vernier microwave frequency comb (VMFC) is proposed and demonstrated. The microwave frequency comb is generated from a mode-locked fiber laser (MLFL). A fiber ring functions as both a sensor head and a microwave photonic filter. The Vernier effect is generated on the photodiode recovered microwave frequency comb after the laser pulses pass through the fiber ring. The sensing information can be deduced by tracking the shift of the envelope of the VMFC. The experimental results show that such a sensor has a good linear response when acting as a temperature sensor.