Modeling of a pulsed CO/N2 molecular laser system

Abstract

A detailed numerical model has been developed for characterizing the important energy‐transfer processes operative in the CO/N₂ dc discharge laser system. The model is based upon a rate‐equation formulation which includes 30 levels of both CO and N₂ and treats multiquantum electron‐molecule excitation processes, single‐quantum vibration‐vibration exchange and vibration‐translation energy‐transfer processes, and both harmonic and overtone spontaneous emission terms. In this paper the time evolution of the CO vibrational distribution with and without N₂ is calculated, and the associated small‐signal gain is predicted and compared to the measurements of Jeffers and Wiswall. Good agreement is obtained between the predicted and measured delay times to maximum gain in a pulsed CO laser system for reasonable assumptions on the important system parameters. The variation in these predicted gains and time delays is explored for various values of the electron density, the translational‐rotational temperature, and the effect of added N₂ as a contribution toward improved experiment design in furthering the understanding of the phenomenology in the pulsed CO/N₂ laser system.