Extra-narrowband metallic filters with an ultrathin single-layer metallic grating

Wang Ran^{1, 2}, Gong Qi-Huang^{1, 3, 4}, Chen Jian-Jun^{1, 3, 4, †}

(a) SEM image of the 2D orthogonal grating with the periods of P₁ = 400 nm and P₂ = 430 nm. (b) Zoomed-in SEM image of the 2D orthogonal grating. Experimental transmission spectra of the samples under (c) p-polarization, (d) s-polarization, and (e) 45° polarization incident beam illumination.