Pulsed Laser Deposition, PLD technique was used to fabricate ZnS thin films deposited on crystalline substrate of Al2O3 under high vacuum condition. The deposition conditions were optimized. The laser induced plasma LIP, spectroscopic technique was used to diagnose the plasma produced by laser ablation. Elemental analysis by energy dispersive X-ray spectroscopy (EDX) indicates higher S content in ZnS films produced at higher fluence. Interferometery was used to measure the thickness of the films, UV/VIS absorption as will as fluorescence spectroscopy was carried out on both thin layers and bulk samples. Blue shift was obtained in absorption and emission spectra indicating the confinement of the film.