Abstract：Based on urgent needs for quantity traceability of ultra-low frequency vibration measuring instruments on research fields such as Structural Dynamics, Geophysics and Seismic Geophysical Prospecting etc., the ultra- low frequency (~0.002Hz) and large amplitude (1mp-p) laser interferometry vibration magnitude and phase measurement technology is researched. According to the fact that the tracking measurement capability of laser interferometry will deteriorate in the case of the dynamic ultra-low frequency and large amplitude, the homodyne quadrature laser interferometer with DC output characteristic is developed. To solve the key technical problem of the difficulty to collect and process data，because of the enormous data in the range of ultra-low frequency, Self-adaptive Dynamic Decomposition Algorithm is presented. Experimental data of the quartzose flexible accelerometer is given. The results show that this measuring system can accurately measure the magnitude and phase of acceleration with laser interferometry in the frequency range of 0.002Hz~2kHz and the dynamic optical path of more than 1m.
2011, Vol. 30 
