A novel optical accelerometer

Frequently, assessment and monitoring of mechanical (acoustic) vibrations is necessary in large structures. Cost and reliability are major issues for field-deployment. We present a simple, compact and reliable optical accelerometer designed and constructed in our labs, capable of consistent and reliable measurement of vibrations in intermediate acoustic range (few Hz to few kHz), based on variation of optical power coupling between fibers in the optical sensor head. The device sensitivity has a lower limit to accelerations as low as 1 g, but has a surprising upper value above 180 m/s/sup 2/ (18 g).