Shen, Bing Wang, Peng Polson, Randy Menon, Rajesh Media 4: Integrated metamaterials for efficient and compact free-space-to-waveguide coupling Originally published in Optics Express on 03 November 2014 (oe-22-22-27175) 03 November 2014;media;oe;Optics Express;free-space-to-waveguide;metamaterial;Integrated 2014-11-03
    https://opticapublishing.figshare.com/articles/media/Media_4_Integrated_metamaterials_for_efficient_and_compact_free-space-to-waveguide_coupling/4947560
10.1364/OE.22.027175.m004