Excitation Process of the N2 IR (B3Πg-A3Σu+) Laser Transition. II

Abstract

The excitation process of the IR (B3Πg-A3Σu+) laser action in the N2 molecule is investigated by rate equation analysis of the time lag between the uv (C3Πu-B3Πg) and IR laser pulses in an axially-excited N2 laser. It is found that with an increase in pressure the main excitation process of the upper IR laser level changes from direct electron impact excitation inclusive of the cascade process due to the UV laser action to collisional excitation transfer from the a1Πg metastable state. The collisional excitation transfer dominates the excitation process for the upper IR laser level at optimum pressures for the IR output power. The time-dependent behaviors of the quantities relevant to the IR laser action in the proposed model are given in detail.