In the present work, a novel proof oc concept for rewritable ultra high density nano optical data storage devices has been discussed. Nano silver films are prepared on glass substrates by DC Magnetron sputtering technique at lower temperature (T= 150 K). When these films are oxidised and are irradiated with blue light (λ= 485 nm), a fluorescence emission is observed in the red region (μ ~ 650 nm) . These films are analysed by XRD and AFM. Emission spectrum was recorded using fluorometer. Films of thicknesses 50Å to 600Å are prepared and compared the fluorescence properties. It is observed that the fluorescence emission from the silver clusters depends on growth parameters in sputtering (like substrate temperature or deposition rate) and on the oxidation temperature.