Photorefractive effects in the organic crystal 2-cyclooctyIamino-5-nitropyridine (COANP) doped with 7,7,8,8-tetracyanochinodimethane (TCNQ)

Abstract

Photorefractive effects (due to electro-optic index change driven by photoinduced space-charge fields) have been found in a wide range of inorganic materials such as LiNbO3, KNbO3, Bi12SiO20, BaTiO3, GaAs, InP:Fe and others. To our knowledge, no such effects have been reported yet for an organic crystal. In this paper we report the observation of photoinduced gratings in an electro-optic molecular crystal which has been intentionally doped to induce photorefractive properties.