Photoinduced birefringence and cooperative molecular reorientation in azo copolymer: optical characterization for rewritable memory application

Abstract

In this paper, new azobenzene copolymers (PCDY and PPDY) with large photoinduced birefringence and good long-term stability of a recorded data have been introduced. The largest photoinduced value of 0.289 was obtained on the PCDY50 at 458 nm light irradiation. This value was brought about a result of molecular cooperative reorientation of cyanoazo and bisazobenzene moieties. It should be noted that the PCDY50 exhibited quite stable characteristics on the archival viewpoint. Furthermore, if we can optimize experimental conditions, more than 10 5 cycles of reversible data storage could be achieved. Making use of these superior characteristics of the PCDY50, an application for rewritable holographic memory and/or other optical addressable devices is anticipated.