Ultrathin Nonlinear Metasurface for Optical Image Encoding Walter, Felicitas ; Li, Guixin ; Meier, Cedrik ; Zhang, Shuang ; Zentgraf, Thomas Abstract Publication: Nano Letters Pub Date: May 2017 DOI: 10.1021/acs.nanolett.7b00676 Bibcode: 2017NanoL..17.3171W