Tunable and efficient terahertz radiation generation by photomixing of two super Gaussian laser pulses in a corrugated magnetized plasma

摘要

A scheme of terahertz (THz) radiation generation is investigated by photo-mixing of two super Gaussian laser beams having different frequencies (ω_1, ω_2) and wave numbers (k_1, k_2) in a performed corrugated plasma embedded with transverse dc magnetic field. Lasers exert a nonlinear ponderomotive force, imparting an oscillatory velocity to plasma electrons that couples with the density corrugations (n' = n_(α0)e~(iαz)) to generate a strong transient nonlinear current, that resonantly derives THz radiation of frequency ～ω_h (upper hybrid frequency). The periodicity of density corrugations is suitably chosen to transfer maximum momentum from lasers to THz radiation at phase matching conditions ω=ω_ 1-ω_2 and k = k_1 - k_2 + α. The efficiency, power, beam quality, and tunability of the present scheme exhibit high dependency upon the applied transverse dc magnetic field along with q-indices and beam width parameters (α_0) of super Gaussian lasers. In the present scheme, efficiency ～10~(-2) is achieved with the optimization of all these parameters.