Fourier-Transform Evaluation Of Holographic Interference Patterns

The Fourier-transform method pointwisely determines the interference phase distribution of a digitally recorded and stored holographic interference pattern. Only one interference pattern is used, although the use of two patterns with an unknown mutual phase shift enables a sign correction with high reliability. The method offers means for filtering out disturbances such as speckle noise and background variations, especially when an image of the illuminated object-surface can be recorded before producing the interference fringes.