Real-time vibration measurement by a spatial phase-shifting technique with a tilted holographic interferogram

摘要

Real-time vibration measurement by a tilted holographic interferogram is presented that utilizes the real-time digital fringe processor of a video signal Three intensity data sampled at every one-third of the fringe spacing of the tilted fringes are used to calculate the modulation term of the fringe that is a function of a vibration amplitude. A three-dimensional lookup table performs the calculation in a TV repetition rate to give a new fringe profile that contours the vibration amplitude. Vibration modes at the resonant frequencies of a fiat speaker were displayed on a monitor as changing the exciting frequency of vibration. (C) 1997 Optical Society of America