High-efficiency multiple imaging in three-dimensional space

Abstract

A technique of the high-efficiency formation of identical multiple images of a monochromatic object within three-dimensional space is proposed and investigated. The central points of these images are located in the points of a regular three-dimensional free-space lattice. The image replication is achieved by the spatial-frequency filtering based on the multiple uniform splitting of the angular spectrum of the object. Within each useful spectral group, all the transverse and longitudinal spectral components of the object are shifted by its own constants along the corresponding three spatial-frequency directions. To this end, a coherent optical processor is employed, which contains a special phase diffractive element in its Fourier plane. The phase function of the element is the superposition of the phase functions of a diffractive multifocal lens and a two-dimensional diffractive fan-out (Dammann-type) grating. The results of numerical simulation are given for a particular case of using a 4-level phase diffractive element and generating the wave field with a regular 3 × 3 × 3 array of main intensity maxima.