Extreme THz fields from two-color filamentation of mid-infrared laser pulses

Abstract

Nonlinear THz photonics is probably the last frontier of nonlinear optics. The strength of both the electric and the magnetic fields of these ultrashort low frequency light bunches opens the way to exciting science and applications. Progress in the field though is slow because of the deficiency in suitable sources. Here we show that two-color filamentation of mid-infrared 3.9 um laser pulses allows one to generate single cycle THz pulses with multi-millijoule energies and extreme conversion efficiencies. Moreover, the focused THz peak electric and magnetic fields reach values of GV/cm and kT, respectively, exceeding by far any available quasi-DC field source today. These fields enable extreme field science, including into other, relativistic phenomena. Besides, we elucidate the origin of this high efficiency, which is made up of several factors, including a novel mechanism where the harmonics produced by the mid-infrared pulses strongly contribute to the field symmetry breaking and enhance the THz generation.

6 pages, 6 figures

Cited by in corpus (4)

• Gas-plasma based generation of broadband THz radiation with 640 mW average power
• Flat liquid jet as a highly efficient source of terahertz radiation
• Boosting terahertz-radiation power with two-color circularly polarized midinfrared laser pulses
• Generation of intense terahertz radiation by two-color filamentation of laser pulses with different wavelengths