Near-field optical recording on a CdSe nanocrystal thin film

We demonstrate an optical recording on a CdSe nanocrystal (NC) thin film by using near-field scanning optical microscopy. Both positive and negative luminescent images were recorded on the CdSe NC thin film by utilizing photoluminescence (PL) enhancement and photobleaching, respectively. Since the PL enhancement is reversible, CdSe NC thin films are exploitable as rewritable optical recording media. On the other hand, CdSe NC thin films can also be used as write-once media when one utilizes photobleaching. The possibility of high-density optical storage on CdSe NC thin film is shown.