The assisted photochemical conversion of precursor polymer synthesized via the procedure using tetrahydrothiophenium group is studied, particularly the influence of the substrate temperature and duration of the illumination period followed by optical absorption measurements. The optimal experimental conditions are obtained for a substrate temperature T = 110 degrees C and an illumination period of at least 30 min. The characterization of the optimized photochemically converted poly(p-phenylene vinylene) [PPV] has been investigated by means of optical absorption, infrared absorption, X-ray diffraction and resonant Raman scattering spectroscopy, We find that optical and structural properties of the optimized photoconverted are rather close to those of standard PPV.