LAUSR

The physical understanding for retrieving super-resolution pits using metal thin films in optical information storage is given, where the reflection modulations both of bright and dark fields are demonstrated experimentally due to the reflection intensity change of metal thin films. A pump-probe setup is constructed to explore the transient reflection intensity change under different pump light intensities. The results show that the reflectivity increases for Al thin films while the reflectivity decreases for Cu and Zn thin films, corresponding to the reflection modulation of the bright and dark fields, respectively. The frequency response function also verifies that the cutoff frequency is extended through reflection modulation. This work gives an understanding on the optical super-resolution readout effect of metal thin films and is very useful in promoting the development of nano-optical information storage. (C) 2016 Optical Society of America