Absorption waves interaction in gas and plasma

摘要

Mechanisms of absorption wave of laser radiation and spectral characteristics of laser plasma were investigated at a laser breakdown in a normal atmosphere. Q-switched Nd:YAG laser operated at 1064 and 532 nm were used in experiment. Laser pulse consisted of prepulse and basic pulse for both laser wavelengths. Time interval between pulses was 15 ns, time duration (FWHM) was 4 ns for 532 nm wavelength, 5 ns for 1064 nm wavelength. Molecular emission and collapse of intensity of plasma continuum during the initial moments of laser plasma expansion were registered. It was carried out examination of colliding plasmas interaction which depended on absorption wave mechanism and distance between focal points of lens. The magnification of integrated intensity in case of plasmas interaction is registered. Decay time of continuous spectrum and lines emission was increased thus contrast of emission lines was also increased.