Unimodal distribution of terahertz emission from single-color filament plasma

Abstract

Abstract We study the angular distributions of various spectral components of terahertz radiation generated in an air plasma of a single-color filament with a laser wavelength of 930 nm. It is experimentally shown that at a 20-fold excess over the critical power for self-focusing the distribution of terahertz radiation at all studied frequencies is unimodal. The obtained pattern differs significantly from the angular distribution of terahertz radiation observed in the case of filamentation of pulses with a shorter wavelength.