Comparison of the temperature dependence of optical poling between guest-host and side-chain polymer films

A comparison of temperature-dependent optical poling between two azopolymer s, a side-chain polymer system (disperse red 19-functionalized polyimide po lymer) and a guest-host polymer (dispersed red 1-doped polymethyl methacryl ate), has been performed at various poling temperatures ranging from 25 to 70 degrees C. The observed saturation levels of induced second-order nonlin ear susceptibility in all cases could be resolved into two components with a faster and a slower decay process after poling, which were respectively a ttributed to the cis-to-trans isomerization and the loss of induced polar o rder by orientational diffusion of azo chromophores. The saturation level a nd its slower decay component were observed to increase with the increase o f poling temperature in the side-chain polymer, but to decrease in the gues t-host system. The faster decay components were observed to decrease with p oling temperature in both the systems. The decay times of the faster compon ent decreased with temperature in the two polymers. The decay times of the slower component in the guest-host polymer, which were much smaller than th ose in the side-chain polymer, also decreased with temperature. All the obs ervations have been explained physically. (C) 1999 American Institute of Ph ysics. [S0021-8979(99)07202-3].