Abstract

A vibration sensor using fiber Bragg gratings has been demonstrated for monitoring broadband vibrations. Linearity of the one-side slope of the reflection spectrum was evaluated. A light-voltage conversion circuit was constructed with a photodiode and a dual operational amplifier. The circuit has a monitoring port to measure the direct current generated from the photodiode. By monitoring and stabilizing the direct current, temperature-insensitive and reproducible vibration sensing can be achieved. The 3-dB frequency bandwidth of the circuit was measured to be from 0.3 Hz to 50 kHz. To evaluate the vibration sensor, we have conducted impact tests. In response to the impact on a metallic plate, vibrating waveforms were observed, and components up to 90 kHz were observed in the Fourier spectrum.

© 2016 Optical Society of America