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A magnetized plasma embedded with clusters offers an efficient way to second harmonic generation by intense short pulse laser. An X-mode laser exerts second harmonic pondermotive force on cluster electrons and produces a nonlinear current, driving the second harmonic radiation. In the process of hydrodynamic expansion of clusters, the electron plasma frequency passes through the surface Plasmon resonance, leading to resonant enhancement in the harmonic yield. The magnetic field shifts the Plasmon resonance. For typical parameters one may achieve power conversion efficiency of a few percent at normalized laser amplitude to (electron drift velocity of speed of light) of 0.1.

A scheme of terahertz generation, employing carbon nanotubes (CNTs) embedded metal surface is proposed. The surface is irradiated by two laser beams at angle of incidence θ. The lasers exert a ponderomotive force on CNT electrons at the beat frequency ω=ω1-ω2 and produce a nonlinear current, turning the nanotubes into an array of antennae emitting beat frequency THz radiation. The THz field is resonantly enhanced at the plasmon resonance, ω = ω p β / 2 , where ωp is the plasma frequency of the CNT electrons and β is a parameter that characterizes the metallic susceptibility of the CNTs. The collisions are a limiting factor and cause heating of CNTs.