ИСТИНА

Driven by high-power laser radiation in the mid-infrared range, plasma currents become a source of secondary ultrabroadband radiation in the terahertz (THz) and microwave ranges. For its correct and complete spatial, spectral, and polarization characterization, it is necessary to use a whole complex of various complementary measurement techniques of ultrafast optics, THz photonics and microwave electronics. For the purpose of a comprehensive analysis of the generated microwave-THz supercontinuum, in the presented work, a combination of methods of electro-optical sampling and autocorrelation analysis is used together with radio-electronic measurements using coaxial-wave adapters and broadband horn antennas. Such a set of detection techniques provides an accurate description of the spatial, spectral, and polarization properties of the generated microwave-THZ supercontinuum in the range from 0.1 GHz to 17 THz, which has a wide-angle pattern and exhibits features of the secondary radiation of longitudinal and transverse laser induced plasma currents. This research was supported in part by Russian Foundation for Basic Research (Project Nos. 20-32-90228, 20-21-00140), Russian Science Foundation (Project Nos. 20-12-00088, 22-22-00955, 22-22-00964), and Theoretical Physics and Mathematics Advancement Foundation «BASIS» (Project No. 18-2-6-157-1).