The photorefractive effect of the organic/inorganic polymer composite based on the chemically hybridized CdS-PVK nanocomposite doped with DO3 NOL chromophores and plasticizer 9-ethylcarbazole (ECZ) is reported. The CdS particles, acting as photosensitizers, show a nanoscale size in PVK adopting transmission electron microscopy. The photoluminescence (PL) spectra of CdS-PVK nanocomposite are studied. In order to approximate relative energy-level positions, the oxidation/reduction potentials of the chromophore DO3 are investigated by cyclic voltammetry. An asymmetric two-beam coupling confirms the photorefractivity of CdS-PVKDO3ECZ gain of 35.4 cm-1 and a diffraction efficiency of 3.4% is obtained without the external field.