Optimal conditions for the emission from a He–Ne laser as a result of the 4d'4–3p9 transition in Ne at λ ≈ 2.4 μm

An experimental investigation was made of the dependence of the power of the radiation emitted as a result of the 4d'₄–3p₉ transition on the parameters of the active medium and the resonator. The optimal values of the pressure and composition of the mixture, of the discharge current, and of the reflection coefficient of the exit mirror needed to ensure such lasing were found. Under the optimal conditions the output power was 0.02 mW. The gain was 0.4 m ^– 1. The mechanism of a population inversion responsible for the investigated transition was analyzed.