Diffraction efficiency of focused-image holograms obtained with multimode laser radiation

A theoretical explanation is given of why an increase in the number of modes in laser radiation alters (reduces) the diffraction efficiency of focused holograms obtained by diffuse scattering of the reference beam. It is shown that the visibility of interference fringes obtained in recording of these holograms is governed by the degree of the temporal coherence of the radiation so that it is possible to derive the theoretical dependence of the diffraction efficiency on the number of longitudinal modes and this dependence is in good agreement with the experimental results.