Copying low spatial frequency holograms in silver halide emulsions: The influence of the bleach bath

We present an available and low cost technique for the production of binary-phase diffractive optical elements designed by digital methods. We produce binary-amplitude holograms making use of a high resolution graphic device. They are used as binary masks which are copied on silver halide photographic emulsion. The behaviour for low spatial frequencies of three different bleaching processes has been studied. Finally, we have applied the technique for the production of filters for optical correlation. As a conclusion, we find that solvent and conventional bleaches are more suitable for low spatial frequency holograms than the fixation-free rehalogenating bleach.