Dynamic readout of subdiffraction-limited pit arrays with a silver superlens

Recent theoretical and experimental results suggested that the silver superlens could be constructed through controlling silver thin film thickness and preparation conditions, and applied in subdiffraction-limited optical imaging and optical lithography. In this work, we report another significant application of silver superlens—ultrahigh density optical data storage. With the silver superlens the subdiffraction-limited pit arrays on an optical disk are dynamically read out and the carrier-to-noise ratio can reach $25dB$ for the thin film thickness of $46nm$⁠. The readout laser power and readout velocity have little effect on the carrier-to-noise ratio. Additionally, in our experiment the silver thin film thickness needs to be controlled in the range from $20to80nm$⁠.