Spectroscopic determination of NO_2, NO_3, and O_3 temporal evolution induced by femtosecond filamentation in air

摘要

By means of a cavity-enhanced absorption spectroscopy technique, we have monitored the temporal evolution of O_3, NO_2, and NO_3 (NO_x) formation after the filamentation of femtosecond laser pulses in air, providing a precise real-time measurement of the accumulative contribution of filaments. We have found that the growth of NO_3 concentration in the atmosphere after the onset of a filamentation regime is 3 orders of magnitude lower than that of NO_2 and O_3. The multi-wavelength feature of the technique allows the simultaneous sampling of NO_x and O_3 directly in the filament region.