Theoretical study of 16-μm laser action from CO2 at low temperatures under conditions of pulsed discharge and externally applied 9.6-μm transfer laser

Abstract

An earlier model developed by others to study the 10.6‐μm laser transition in CO₂ has been extended for studying the 16‐μμ (02⁰0)→(01¹0) laser transition in cold CO₂. The rate equations take into account the rotational relaxation and collisional transfer of population among (02⁰0), (10⁰0), and (02²0) levels of CO₂. The model has been used to study the effect of various parameters on the 16‐μm output. It has been found that at higher pressures the collisional relaxation of the (02⁰0) level can be overcome by application of a more powerful 9.6‐μm pulse to achieve an inversion between the (02⁰0) and (01¹0) levels of CO₂. It is predicted that if transverse excitation is used in these cold mixtures, pulsed powers in excess of 100 kW could be obtained on 16 μm.