Guided mode resonance in planar metamaterials consisting of two ring resonators with different sizes
Yu Zhen, Che Hang, Liu Jianjun, Jing Xufeng, Li Xiangjun, Hong Zhi †
       

(color online) (a) Schematic diagram of a unit cell consisting of two closed square metallic ring resonators with different lengths a1 and a2. Micrographs of two fabricated samples with (b) , and (c) , .