HIGH PHOTOREFRACTIVE GAIN IN NEMATIC LIQUID-CRYSTALS DOPED WITH ELECTRON-DONOR AND ACCEPTOR MOLECULES

Liquid crystalline composite materials have been prepared that are str ongly photorefractive. Nematic liquid crystals were doped with both el ectron donor and electron acceptor molecules that undergo facile, phot oinduced, electron transfer reactions to yield mobile ions. A photoref ractive gain ratio of 1.88 was observed. This gain ratio was achieved with low applied electric fields (0.4 kilovolts per centimeter) requir ing only a 1.5-volt battery and low light intensities (100 milliwatts per square centimeter) in samples 37 to 88 micrometers thick that show ed no loss in gain over a 6-month period.