Micromachined, fiber-optic based accelerometer with shutter modulation

A highly sensitive shutter modulated fiber-optic accelerometer has been fabricated and characterized. Its structure is based on a mass suspended by two side-by-side cantilever beams. A vertical shutter at the free end of the mass can move vertically in the optical path between two multimode optical fibers. Cantilever beams, mass, shutter and optical fiber grooves are fabricated by advanced deep reactive ion etching. The accelerometer is characterized using a supra luminescent diode. A resonance frequency above 1 kHz and a measurement range of ±5 g are measured. To demonstrate the potential of using an economic light emitting diode, an experiment with 2 μW input power was performed. It resulted in a noise equivalent acceleration of 2 mg