Constructive Coherent Microwave Scattering for Studying Femtosecond Filamentation and Tabulating Photoionization Rates

In this study, we report on the use of coherent microwave scattering (CMS) in two distinct applications. First, CMS was employed to perform one-dimensional mapping of 3.9-µm mid-infrared femtosecond laser filaments in air. Second, CMS operated in the low-pressure Thomson regime was used to characterize photoionization rates in oxygen and nitrogen at 800 nm, which are of significant practical relevance to gaseous discharges, combustion science, high-speed aerodynamics, and filamentation physics.