Single-cycle megawatt terahertz pulse generation from a wavelength-scale plasma oscillator driven by ultrashort laser pulses

摘要

The tremendous applications of terahertz (THz) spectroscopy and imagingrequire THz sources in different parameters. We propose a novel scheme togenerate single-cycle powerful THz pulses by ultrashort intense laser pulsesincident obliquely on a tenuous plasma slab of few THz wavelengths inthickness. This is made possible by driving a large amplitude electron plasmawave in the plasma slab, thus producing a net transient current at the plasmasurfaces. Theory and simulations show that such a THz source is capable ofproviding megawatt power and field strength of MV/cm, which may open up newhorizons for nonlinear THz science and applications.