Phase mask for use in holographic apparatus

摘要

A phase mask for use in a holographic apparatus comprising a combination of phase mask and data mask and being so devised that an illuminant beam transmitting these masks is irradiated on a Fourier transform plane together with a reference beam coherent with said illuminant bean, said phase mask being composed of a transparent plate and random undulations formed on the surface of said transparent plate by coating a solution of high molecular weight compound by means of a spin coater.