Reversible photoinduced phase transition and image recording in polymer-dispersed liquid crystals

Abstract
The photoinduced phase transition of nematic liquid crystalline (LC) emulsions containing 4-n-butyl-4'-methoxyazobenzene (BMAZ) was studied in a polyvinylalcohol (PVA) film as a supporting medium. Phase transition was reversible and accompanied by a large change in transmittance as well as a change in birefringence. Photorecording by the method described provided a quick response and long-lasting images due to perfect fixation of LC emulsions into PVA film, unless reverse isomerization of BMAZ takes place. The 3 mu m thick films containing LC emulsions with diameter 2 mu m showed about 6 mu m of resolving power.