Generation of terahertz pulses from tightly focused single near-infrared pulses in double-plasmon waveguides

Abstract

The difference-frequency (DF) nonlinear mixing terahertz (THz) pulse generation from Fourier components of a single tightly focused near-infrared pump pulse in a double-plasmon waveguide is considered. Under an appropriate choice of its parameters, such a waveguide ensures an efficient transverse confinement of the THz field and provides low dispersion of the THz mode refraction index. As a result, the generation of short powerful single-cycle THz pulses becomes possible. In comparison with traditional (without waveguiding) schemes of DF THz pulse generation from a single pump pulse (optical rectification), the proposed method allows one to significantly (by ~50 times) reduce the pump pulse power while providing the same THz pulse output intensity and pump-THz conversion efficiency.