Photorefractive Composites Based on Nanocrystalline Carbocyanine Dye J-Aggregates with a Fast Response Time

The use of carbocyanine dye J-aggregates as sensitizers of photoelectric sensitivity and chromophores with the third-order nonlinear optical polarizability made it possible, by the action of two intersecting He–Ne laser (633 nm) beams and an applied electric field, to obtain photorefractive spatial modulation of the refractive index in a nonplasticized polymer layer having the glass transition temperature of about 230°C with a short (≤20 ms) time of response to this action. A fairly high two-beam-coupling gain coefficient was obtained, which reached a value of Γ = 218 cm–1 at an applied field of E0 = 50 V/μm. The net internal gain (difference between the beam-coupling gain coefficient Γ and the absorption coefficient α) was Γ – α = 143 cm–1 under these conditions.