Fig. 1. Schematic of the metallic nanoslit.

Fig. 2. (a) Comparison between the exact values neff and the rough values neffa, for copper at 0.5 THz. The black curves are the rough solutions neffa and the red curves denote the exact values neff. The solid curves are Re(neffa)−1 and the “o” signs represent Re(neff)−1. The dashed curves are Im(neffa) and the “+” signs show Im(neff). (b) The relative deviation of neffa. The solid curve is the relative deviation of Re(neffa)−1, and the dashed curve represents the relative deviation of Im(neffa).

Fig. 3. Comparison between the exact values and the calculated values of the attenuation coefficient in the width ranging from 1 to 10 mm for copper and 0.5 THz. The red curves are the exact values, and the “o” signs show the calculated values.

Fig. 4. Magnetic field Hy for metal copper and 0.5 THz. (a) The case for the metallic slit with width of 5 nm. (b) The case for the width of 50 nm. (c) The case for the width of 500 nm.