Change of Discharge Current in CO2 Plasma Induced by Q-switched CO2 Laser

A change of discharge current is observed in CO2 plasma by irradiation with a Q-switched CO2 laser. It is elucidated that the increase of the discharge current just after the incidence of laser pulse is a correlated effect with an amplification mechanism of the laser pulse power. Evidence is also presented to support an interpretation that the rise and decay times of the current change produced by the laser pulse are effective measures of the relaxation times of the vibrational levels (10°0) and (00°1) of CO2 molecules in plasma. The effect of foreign gases is also examined.