Abstract

The generation of terahertz (THz) radiation during the propagation of subpicosecond pulses in liquid media is investigated using a theoretical model considering the relative contribution of Kerr and plasma nonlinearity. The dependences of the THz emission generation efficiency on the contribution of plasma nonlinearity with a fixed third-order nonlinearity value revealed the existence of weak and strong ionization modes. It is shown that the transition between these modes is determined by the ratio of plasma to Kerr nonlinearity coefficients and the pump energy. In the strong ionization mode and with the fixed contribution of plasma nonlinearity, the optical-to-THz conversion efficiency decreases with increasing Kerr nonlinearity due to the redistribution of the pump energy for the third-order effects. These results contribute to estimating the potential of liquid media as highly efficient THz sources.

© 2019 Optical Society of America

Intensity modulated terahertz vortex wave generation in air plasma by two-color femtosecond laser pulses

Maksym Ivanov, Illia Thiele, Luc Bergé, Stefan Skupin, Danas Buožius, and Virgilijus Vaičaitis
Opt. Lett. 44(15) 3889-3892 (2019)

Flat liquid jet as a highly efficient source of terahertz radiation

Anton N. Tcypkin, Evgenia A. Ponomareva, Sergey E. Putilin, Semen V. Smirnov, Sviatoslav A. Shtumpf, Maksim V. Melnik, Yiwen E, Sergei A. Kozlov, and Xi-Cheng Zhang
Opt. Express 27(11) 15485-15494 (2019)

Brunel harmonics generated from ionizing clusters by few-cycle laser pulses

Xiaohui Gao, Bonggu Shim, and Michael C. Downer
Opt. Lett. 44(4) 779-782 (2019)

Impact-ionization mediated self-focusing of long-wavelength infrared pulses in gases

Xiaohui Gao and Bonggu Shim
Opt. Lett. 44(4) 827-830 (2019)

Terahertz generation in parallel plate waveguides activated by nonlinear metasurfaces

Symeon Sideris and Tal Ellenbogen
Opt. Lett. 44(14) 3590-3593 (2019)