Plasmonic Optics and Superlenses
Speaker: Zhaowei Liu , UC Berkeley
The imaging resolution of conventional optical lens system is limited by diffraction. Emerging artificially engineered metamaterials offer a new possibility to build a superlens that overcomes such a limit. In 2003, we experimentally proved that a thin silver slab can significantly enhance the evanescent waves thus provide a possibility to form an ultrahigh resolution image in the near field. We further developed two types of superlenses, namely far-field superlens (FSL) and hyperlens, which can bring such high resolution image from the near field into the far field. Our preliminary experimental results for both FSL and hyperlens have shown at least twofold resolution improvement comparing with conventional lenses. The ultimate resolution, which is only limited by the intrinsic material loss and fabrication imperfection, however can be improved much further (~tenfold). The optical superlenses opened new and exciting possibilities for the fields such as real-time nanoscale optical imaging and sensing, nanolithography, and high density optical storage. I will also talk about some of my work in 2D plasmonics such as surface plasmon interference and plasmonic lens.