New near-IR lasing line due to a transition in the chlorine atom

Lasing at $\lambda$ = 904.5 $\pm$ 0.2 nm was observed when a mixture of the Ne:He:CCl$_4$ = 9$\times$ 10$^4$:10$^4$:1 composition was nuclear-pumped at a pressure of 100 kPa. The mixture contained molecular gases as impurities and one of them was N$_2$. It was postulated that this lasing line could be the result of $3p'F^0_{7/2}- 3s'^2D_{5/2}$ ($\lambda$ = 904.6 nm) transition in the N atom. An investigation was made of the influence of the N$_2$ impurity in this mixture on the stimulated emission at $\lambda$ = 904.5$\pm$ 0.2 nm and of the influence of CCl$_4$ as an impurity on the lasing of the N atom ($\lambda$ = 904.6 nm) in a mixture of the Ne:N$_2$ = 25$\times$ 10$^3$:1 composition at a pressure of 25 kPa. The CCl$_4$ impurity had a negative influence on the operational parameters of the nitrogen laser and the addition of N$_2$ to an Ne – He – CCl$_4$ mixture quenched lasing at $\lambda$ = 904.5 nm. It was therefore concluded that the observed lasing line is the result of a $4p^2P^0_{1/2} - 4s^2P_{1/2}$ ($\lambda$ = 904.5 nm) transition in the Cl atom and is a new lasing line.