A novel hole-transporting poly[methyl(3-phenothiazine-10-ylpropyl)siloxane] (PSX-PTZ) was synthesized by a post hydrosililation and it showed low glass transition temperature (T,). The 50 pm thick PR material containing 30 wt.% nonlinear optical chromophore (PSX-PTZ composite) has several attractive feature when compared to the poly(N-vinylearbaz)-based composite, including no need for additional plasticizers. PSX-PTZ composite showed a diffraction efficiency 67% at 30 V/mu m, which corresponded to a speed of 4.2 s. (C) 2008 Elsevier Ltd. All rights reserved.