Speckle reduction in holography with a spatially incoherent source.

High quality holograms of flat objects are produced by developing an achromatic-fringe system that consists of a monochromatic but spatially incoherent source, a holographic beam splitting device, and a pair of Fourier transform lenses. The effects of using an incoherent extended source and the transfer characteristics of the holograms are discussed. Emphasis is also placed on the advantages of developing lens Fourier transform holography along with the practical lens systems. A further possible extension of the system to attain high storage density as well as high quality holograms is proposed by making use of a new type of pseudorandom phase sequence.