Active Vibration Interference In The Study Of The Transient Phase Detection Technology

Firstly, the progress of interferometry anti-vibration is introduced and several methods of active anti-vibration are compared. The influence of vibration sources are also analyzed. Then the method of this article is carried out clearly and phase-subdividing modulating is adopted to detect the motion of interference fringe. Secondly a circuit to measure the motion of fringe is designed. The circuit converts the motion to the phase difference of two 10KHZ pulses by sampling and processing the photoelectric signal. With a complex programmable logic device (CPLD) and a digital signal processor (DSP), the numerical value and direction of the phase difference are obtained. Finally, the circuit is placed on a interferometer platform to conducting many tests. The result of the experiment is satisfying. It shows that the method is applicable. The circuit detects the fringe motion accurately within one fringe.