AC Field Enhancement of Diffraction From Permanent Gratings in Dye-Doped Liquid Crystals

Abstract

Permanent gratings can be written in doped liquid crystals with high dye concentration without any externally applied electric field, using low intensity, visible light. The gratings are adaptive as their diffraction efficiency can be easily modulated and controlled enhanced by an AC field. The diffracted intensity could also be modulated by a low frequency electric field with the magnitude of modulation decreasing for higher frequencies. The permanent gratings are durable, remaining in the cells for over a year even after application of high temperatures