Dynamics of the Nuclear and Electrically Pumped 1.45-μm Atomic Carbon Laser in Mixtures of Helium + CO And Helium + CO₂

The first successful modeling of an impurity-type nuclear pumped laser (NPL) (i.e., one that employs trace densities of the lasing species in a noble gas buffer), atomic carbon at 1.45 μm, was achieved. Such NPLs are important due to their low flux threshold and quasi-steady-state oscillation. The atomic carbon NPL is unique in that time delays up to 5 ms are observed between the laser signal and the excitation pulse in helium + CO₂ mixtures while no delay is observed in helium + CO. Using a kinetic model in conjunction with an experimental program, we show that this difference in delay arises from slow dissociation of CO₂ to form CO. Significantly, the model also successfully simulates electrical pumping of He-CO or CO₂ mixtures.