Micro all-glass fiber-optic accelerometers

A micro all-glass fiber-optic accelerometer based on the extrinsic Fabry–Perot interferometer (EFPI) is developed. A microcantilever beam is fabricated using a femtosecond laser and assembled with a silica tube and a silica inertial mass. Two mirrors, the end face of the leading single-mode fiber and the inner glass/air interface of the cantilever beam, form an EFPI. When the accelerometer is subjected to the vibration along the fiber axis, the vibration is detected by interrogating the variation in the cavity length of the EFPI. The proposed accelerometer has a compact structure and high signal-to-noise ratio. Experimental results show that the sensitivity of 2.9 nm/g@500 Hz within the acceleration range of 0 to 3 g is achieved. The accelerometer can work within the frequency range of 100 to 1500 Hz.