Optical fiber Bragg grating accelerometer

A cantilever beam and fiber Bragg grating is used to measure acceleration. The cantilever induces strain on the grating resulting in a Bragg wavelength modification which is subsequently detected. The output signal is insensitive to temperature variations and for a temperature change from —20 °C to 40 °C, the output signal fluctuated less than 5%without any temperature compensation schemes. Because the sensor does not utilize expensive and complex demodulationtechniques it is potentially inexpensive. For the experimental system a linear output range of 8 g could be detected.Keywords: Optical fiber sensors, fiber Bragg gratings, accelerometer, chirped gratings 1. INTRODUCTION The first fiber gratings were reported approximately two decades ago and since then applications of fiber Bragg gratingsincreased' . Because the optical linewidth ofthe reflected Bragg wavelength can be in the order of 0. 1 urn, the main area ofinterest has been in optical fiber telecommunkation systems such as wavelength division multiplexing, fibre lasers, opticalamplifiers as well as dispersion compensation elements 2•