Optically induced birefringence and surface relief gratings in composite Langmuir-Blodgett (LB) films of poly[4 '-[[2-(methacryloyloxy)ethyl]ethylamino]-2-chloro-4-nitroazobenzene] (HPDR13) and cadmium stearate

Photoinduced trans-cis-trans isomerization, optical storage, and surface re lief gratings are demonstrated in mixed Langmuir-Blodgett (LB) films of pol y[4'-[[2-(methacryloyloxy)ethyl]ethyl amino]-2-chloro-4-nitroazobenzene] (H PDR13) and cadmium stearate (CdSt). The trans-cis-trans photoisomerization of the azobenzene chromophores from HPDR13 in the mixed LB him was achieved with a circularly polarized laser light. The birefringence induced by a li nearly polarized laser light decreased with the number of layers and increa sed with the weight percentage of HPDR13 in the mixed LB film. The surface relief gratings recorded by exposing the mixed LB film to an interference p attern produced by the laser light were visualized through atomic force mic roscopy (AFM). Interestingly, it seems that the nonphotoactive CdSt domains have also migrated along with HPDR13 while recording the surface relief gr atings.