Lu, Zhaolin Shi, Shouyuan Schuetz, Christopher A. Murakowski, Janusz A. Prather, Dennis W. Media 2: Three-dimensional photonic crystal flat lens by full 3D negative refraction Originally published in Optics Express on 25 July 2005 (oe-13-15-5592) Three-dimensional;media;25 July 2005;3 D;photonic;lens;crystal;Optics Express;refraction;oe 2005-07-25
    https://opticapublishing.figshare.com/articles/media/Media_2_Three-dimensional_photonic_crystal_flat_lens_by_full_3D_negative_refraction/4933118
10.1364/OPEX.13.005592.m002