Nonlinear Transparency of Dielectric - Metal - Dielectric 1D photonic crystals in the THz Range

Abstract

The resonant linear and nonlinear transmission properties in THz range of structures dielectric-metal-dielectric … are investigated theoretically. The thicknesses of metallic Ag or Au layers are of about 10 nm. The dynamics of the degenerated electron gas is described within the framework of the quantum hydrodynamic equations where the Bohm term is taken into account. To observe the resonant transmission, at the input there is a dielectric with a higher permittivity, whereas at the output is air. The incidence angle is chosen slightly below the full internal reflection angle. Because the nonlinearity of noble metals is high and almost dissipative, the nonlinearity results in the increase of the electron collision frequency. The transmission of THz electromagnetic waves increases sharply with the increase of the collision frequency. Thus the high dissipative nonlinearity in metals may play positive role in THz range for observing nonlinear phenomena in structures with thin metallic layers.