Fig. 1. Schematic of the polarization filter cell structure. Top layer is a metal compound in rectangular strips. Thickness and the width of the three rectangular strips is h1=20  nm and w=100  nm. Middle and bottom layers are MgF2 and a gold film, respectively. Thicknesses of the MgF2 layer and gold film are h2=50  nm and h3=180  nm, respectively. Dimensions of the filter cell structure in both x- and y-directions are p=600  nm.

Fig. 2. Simulated reflection spectra of the filter with lx1=300  nm, lx2=450  nm, and ly=350  nm for Ex and Ey polarization.

Fig. 3. Distributions of the electric field Ez at the surface of the metal compound rectangular strips corresponding to the following; Ex polarization at the resonant dip (a) 1310 and (b) 2000 nm; (c) Ey polarization at the resonant dip 1516 nm.

Fig. 4. Simulated reflection spectra of the filter structure as a function of the length; (a) lx1 with Δlx1=20  nm and lx2 is fixed at 450 nm; (b) lx2 with Δlx2=20  nm and lx1 is fixed at 300 nm for Ex polarization.

Fig. 5. Simulated reflection spectra of the filter structure as a function of the length of the gold strips lx1 and lx2 with every step of 20 nm at the same time, and ly is fixed at 350 nm for Ex polarization.

Fig. 6. Simulated reflection spectra of the filter structure as a function of the length of the gold strips lx1 and lx2 with every step of 20 nm at the same time, and ly is fixed at 350 nm for Ey polarization.

Fig. 7. Schematic of the dual-band polarization filter cell structure. Top layer is two gold asymmetrical cross resonators. Thickness and the width of the four rectangle strips is h1=20  nm and w=100  nm. Middle and bottom layers are MgF2 and gold films, respectively. Thicknesses of the MgF2 layer and gold film are h2=70  nm and h3=180  nm, respectively. Dimensions of the filter cell structure are px=1000  nm and py=600  nm along the x- and y-directions, respectively.

Fig. 8. Simulated reflection spectra of the filter with lx1=300  nm, lx2=440  nm, ly1=360  nm, and ly2=510  nm for Ex and Ey polarization.

Fig. 9. Simulated reflection spectra of the filter structure as a function of the length of the gold strips lx1 and lx2 with every step of 20 nm at the same time, while ly1 and ly2 are fixed at 340 and 490 nm, respectively, for Ex polarization.

Fig. 10. Simulated reflection spectra of the filter structure as a function of the length of the gold strips ly1 and ly2 with every step of 20 nm at the same time, while lx1 and lx2 are fixed at 300 and 440 nm, respectively, for Ey polarization.