Various methods of vibration analysis using holography, that is, time average method, stroboscopic method and other modified methods are reviewed. Characteristic features and practical problems of each method are discussed and several reconstructed images of vibrating objects with interference fringes which are the contour lines of the amplitude of vibration are shown.
Holographic technique enables us to visualize vibration pattern on a rough surface of any shape without touching it. The distribution of vibration amplitudes from a fraction of one wavelength to more than 25 wavelengths of the light can be obtained. Relative phases of vibration between various object points can also be measured by some modified methods.
These unique advantages over conventional methods of vibration analysis make holography an indispensable technique for practical vibration analysis.