We prepared the side-chain electro-optic polymers by the active bonding of cyanate- and hydroxy-functional groups, and employed these side-chain polymers as hosts for the bi-chromophore system to enhance the electro-optic coefficient (r(33)). In singular chromophore polymer (in PMMA host), the dependence of EO response on loading concentration was examined, r(33) about 26 pm/V was obtained. In order to further incorporate the chromophore. the loading behavior in binary chromphore systems was investigated. The optimal r(33) more than 40 pm/V was achieved, which was almost the sum of two individual polymers. Furthermore, the temporal stability at room temperature and 85 degrees C, respectively, over 500 h was evaluated for the potential application on electro-optic devices. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.