Composite thin films of PbTiO3 nano-crystals and high transparency polymer polyetherketone(PEK-c) for application of non-linear optical devices were prepared by spin coating. The size of PbTiO3 nano-crystals was estimated to be 30-40 nm using a transmission electron microscope. The refractive index and the mode propagation losses at 633 nm were measured using the prism coupling technique and improved photographic technique respectively. They were found to be 1.6545 and 2.00 dB cm-1 (fundamental mode),respectively. Moreover, it is observed that this loss is increased at higher mode indices.