Investigation of Detecting Ultrasound Using a Long Period Grating

Abstract

A long period fiber grating (LPFG) sensor, useful for the detection of ultrasound is proposed and experimentally demonstrated. Some preliminary results are got that (indicate (the capability of the LPG sensor to successfully monitor ultrasound. The resonance wavelength of LPG is linearly related to the amplitude of the ultrasonic wave, and the frequency and duration of the ultrasonic wave hardly change the resonance wavelength. Experimental results showed that LPFG sensors could be applied to determine the corresponding parameters of ultrasonic field (by demodulating the shift of the resonant band of the LPFG.