Practical fiber-optic-based submicro-g accelerometer free from source and environmental perturbations

We describe a novel accelerometer in which the sensing element is a weighted diaphragm designed to have minimal cross coupling. The displacement of the diaphragm, produced by acceleration, is measured by using two miniature hemispherical air-spaced Fabry-Perot interferometers, one constructed on either side of the diaphragm. The output of the two interferometers is processed such that the detrimental effects caused by wavelength drift of the source and variation in temperature of the sensor are reduced by 45.8 and 27.3 dB, respectively, compared with those of a single interferometer.