Fig. 1

a Perspective view of the PNS. b Vertical view of the PNS as four nanoholes shrink (Δ < 0) or expand (Δ > 0) along the diagonals of the superlattice. c Transmission spectra of the PNS as a function of the shift distance of Δ. The PNS is under the illumination of the x-polarized incident wave with the incident angle of θ = 0. The parameters of the PNS are: Λ = 350 nm, r = 35 nm and H = 175 nm