Performing accelerometer calibration using homodyne laser interferometry with displacements smaller than a quarter wavelength

Abstract

<p class="Abstract"><span lang="EN-US">Laser interferometry is a preferred method of realizing the National Measurement Standard for vibration by National Metrology Institutes. Laser interferometry is well documented and its detailed implementation described in ISO 16036, part 11. When employing Homodyne demodulation of the quadrature signals, the minimum peak to peak displacement is limited at a quarter of the wavelength, or half a circle when viewed on a lissajous plot. A novel technique is described to extend the vibration calibration frequency range from 10 kHz up to 20 kHz with an applied acceleration of 200 m/s². </span></p>