Characterization of A High-Repetition-Rate Laser Filament-Induced Plasma in Air Using Optical Emission Spectroscopy

Simulation and characterization of plasma-chemical kinetics for laser-induced filamentation experiments become increasingly critical as novel laser systems give access to increasing repetition rates, where accumulation effects cannot be ruled out due to the short time between pulses [1]. Previous studies of filament plasmas have focused mainly on retrieving the electron density, neglecting the plasma's molecular composition and its effect on its optical properties. Therefore, we focused on investigating how accumulation effects affect the photochemical reactions at higher laser repetition rates and their influence on the molecular composition of the resultant plasma by measuring the time-dependent plasma dynamics and parameters (gas temperature, electron temperature, electron density, and species-specific decay times) of laser-induced filaments at a repetition rate of 10 kHz.