Terahertz monolayer metamaterials modulated by high power THz lasers

Abstract

The Terahertz laser modulating processes of monolayers of spheres have been theoretically investigated by using density functional and electromagnetic scattering method. The introduced free energy including static energy, electronic excitations and atomic vibrations was calculated by the density functional method. Thus, the heat capacity, the coefficient of thermal expansion and dielectric constant of materials could be obtained at various temperatures. When the high power THz laser passes through a CdTe sphere, the temperature traces can be changed and calculated by setting any laser waveforms. At a special frequency point, the real parts of permittivity could exhibit an oscillation with double modulation frequency. Furthermore, it was found that the resonance of monolayers could be dynamically tuned, and the oscillation behaviors of transmission are consistent with the modulation waveform. Finally, the resonant frequencies at Terahertz regions could be shifted to a given frequency by adjusting the lattice constants of monolayers.