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arXiv · 1908.11136

Bright single-cycle terahertz source based on gas cells irradiated by two-color laser pulses

T. V. Liseykina·S. V. Popruzhenko
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Abstract

We study the excitation of electron currents in a transparent cell of sub-millimeter size filled by an atomic gas and illuminated by an intense two-color femtosecond laser pulse. The pulse consists of a strong fundamental component and its second harmonic of low intensity, both circularly polarized. We show that for sufficiently small $20\mu$m cells the plasma oscillation excited by asymmetric ionization is almost spatially homogeneous within the interaction volume. This coherent dipole plasma oscillation results in a remarkably efficient conversion of the electron energy into that of radiation emitted in the terahertz frequency domain. Simultaneously, strong quasi-static electric fields of maximal strength $E_m\simeq 10$MV/cm are shown to exist inside the cell during several hundred femtoseconds after the ionizing two-color laser pulse has gone.

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T. V. Liseykina, S. V. Popruzhenko. 2019-08-29. Bright single-cycle terahertz source based on gas cells irradiated by two-color laser pulses. https://doi.org/10.1088/1742-6596/1412/4/042005

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