Residual-current excitation in plasmas produced by few-cycle laser pulses.
Along with the generation of extreme-ultraviolet and soft x-ray radiation, gas ionization by an intense few-cycle laser pulse can also induce the generation of low-frequency terahertz waves. The latter is caused by the excitation of a residual quasi-dc current in the produced plasma by the electric field of the laser pulse. We describe this phenomenon using the quantum-mechanical approach based on solving the 3D time-dependent Schrödinger equation. We calculate the dependences of the residual-current density on the carrier-envelope phase, duration, and intensity of the few-cycle laser pulse, and find optimal conditions for high-efficiency realization of the studied phenomenon.
Silaev
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AA
Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod 603950, Russia.
Vvedenskii
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NV