FIBEROPTIC ACCELEROMETER USING SILICON MICROMACHINING TECHNIQUES

The sensor, located at the end of a multimode fibre, is based on the p rinciple of light intensity modulation, The movement of a micromachine d silicon cantilever beam is measured in relation to the vibration amp litude. The innovative topology of the optical set-up yields measureme nts completely independent from all losses and drifts that might occur in the optical chain. The design and construction of the silicon stru ctures are presented and packaging requirements are discussed. The pri nciples and techniques of both measurement and compensation are addres sed. Typical accelerometer characteristics are: a resonance frequency of 1.3 kHz and a rate of detection of less than 0.2g for a 60g full sc ale. Linearity is better than +/-5% and thermal drift is less than 0.1 5% degrees C-1.