Fig. 1. Real part of the effective refractive index neff versus the incident wavelength λ and the slit width w in the MIM waveguide.

Fig. 2. Structure schematic of a slit MIM SPPs waveguide with three rectangle resonators.

Fig. 3. (a) Transmission spectrum of the MIM waveguide with two of the same side-coupled resonators; the contour profiles of the magnetic intensity distributions |Hz|2 of the device at (b) λ0=680  nm and (c) λ0=1334  nm.

Fig. 4. (a)–(f) Off-to-on (left peak) transmission spectra of a three rectangle resonator PIT system with different L1 values. (g)–(l) Off-to-on (right peak) transmission spectra of a three rectangle resonator PIT system with different L2 values.

Fig. 5. Transmission spectrum of the MIM waveguide with three rectangle resonators when L1=510  nm; the contour profiles of magnetic intensity distributions |Hz|2 of the device are at (a) λ=1289  nm, (b) λ=1334  nm, (c) λ=1414  nm, (d) λ=1306  nm, and (e) λ=1379  nm.

Fig. 6. (a) Off-to-on transmission spectra of a three rectangle resonator PIT system with different L values. (b) Off-to-on transmission spectra of three rectangle resonators PIT system with different d3 values.

Fig. 7. Transmission spectrum of the MIM waveguide with three rectangle resonators when L=50  nm; the contour profiles of the magnetic intensity distributions |Hz|2 of the device are at (a) λ=1289  nm, (b) λ=1334  nm, (c) λ=1388  nm, (d) λ=1306  nm, and (e) λ=1364  nm.