Cavity-Free Lasing from Molecular Nitrogen Ions in Air Laser Plasma

—The paper presents the results of a study of the temporal and spectral characteristics of lasing at transition of molecular nitrogen ions in laser plasma created by a radiation pulse with central wavelength of 950 nm, duration of 60 fs and energy of 10 mJ. The parameters of the active medium are analyzed and a possible mechanism for the formation of picosecond duration of the radiation pulse is discussed.