Holography with Light Beams of Finite Spectral Width

The effects of spectral coherence on holographic images have been analysed in terms of the Fresnel-transform formulation of the process of holography. In this paper the case of very rough object or diffuse illumination has not been considered. The results have been obtained as contrast modulation in the image of a spatial frequency component in the object. The effect of polychromaticity in the recording beam is seen to be more severe than that due to the polychromaticity in the reconstruction beam. Fourier-transform holography seems to yield a better image. With the lensless Fourier-transform hologram recorded on monochromatic light, white light reconstruction seems to be possible if the illuminating beam is suitably dispersed before it falls on the hologram.