Optical shutter driven photochemically from anisotropic polymer network containing liquid crystalline and azobenzene molecules

Polymer-dispersed liquid crystal (PDLC) with macroscopically uniaxial molecular alignment containing azobenzene molecules was produced. The PDLC was transparent because of this alignment. Upon photoirradiation to cause trans-cis photoisomerization of azobenzene molecules, the PDLC became translucent even at 30 degrees C. The PDLC system does not require the use of polarizers and electrodes to fabricate optical devices. The light scattering is ascribed to a biphasic morphology in the system produced transiently by means of the photochemical phase transition. (C) 1998 American Institute of Physics.