Terahertz emission pattern from a single-color filament plasma

We study the angular distribution of different spectral com-ponents of the terahertz emission from a single-color laser filament plasma. The opening angle of a terahertz cone is experimentally demonstrated to be proportional to the inverse square root of both plasma channel length and tera-hertz frequency in the non-linear focusing mode, whereas in the case of linear focusing this dependence breaks down. We also experimentally show that any conclusions of terahertz radiation spectral composition require the angle range from which it is collected to be specified. (c) 2022 Optica Publishing Group

Automated summary

We investigate the angular distribution of different spectral components of terahertz emission from a single-color laser filament plasma. The experimental results show that the opening angle of a terahertz cone is proportional to the inverse square root of both the plasma channel length and terahertz frequency in the non-linear focusing mode, but this relationship breaks down in the case of linear focusing. We also demonstrate experimentally that any conclusions about the spectral composition of terahertz radiation need to specify the angle range from which it is collected.