3-axis accelerometer based on lasers locked to π-shifted fibre Bragg gratings

We report on the development of a high-bandwidth, 3-axis accelerometer using π-shifted fibre Bragg gratings. The gratings are inserted into a cantilever system and interrogated by three separate telecom-grade distributed-feedback diode lasers. These lasers are frequency locked to the sensors using a radio-frequency Pound-Drever-Hall technique. This scheme reduced the effect of laser's amplitude noise and allowed for an acceleration dynamic range of at least 20 g. An operation bandwidth of 500 Hz is demonstrated so far with sensitivities between 20 and 50 μg/√Hz.