| 초록 |
Hyperbolic metamaterials (HMMs) can be made by stacking layers consisting of metal and dielectric pairs (Multilayer structure) or placing metal nanorods inside of dielectric (Vertical structure). In comparison with multilayer structure HMM that employ resonances, vertical structure HMM does not require any resonance. Through this feature, it reduced resistive losses and broadened the working frequency. Here, we have simulated the vertical structure for negative refraction with various combination over the visible range. Al rod has been chosen as a metal and changed its size from 20 nm to 40 nm. At the same time, the dielectric part has also been changed by Al2O3, ZrO2, TiO2, SiO2, and HfO2. With calculation of Poynting vector to check the directional energy flux of an electromagnetic field, we ensured negative refraction of each combination. The combination we found will show negative refraction in the visible range and light manipulation over broad wavelength region can be achieved. |
