Theory of formation of phase holograms in lithium niobate

Abstract

The production of refractive‐index gratings by photoexcitation of electrons from traps followed by drift or diffusion and then retrapping is treated without the assumption made by Amodei that the migration or diffusion length is small compared to the grating wavelength. It is shown that the efficiency of hologram writing increases with increasing diffusion or migration length up to a certain limit. The spatial shift between the refractive‐index grating and the light‐intensity pattern which produces it is different according to whether drift or diffusion is operative only for short drift lengths.