Investigation of quasi-cw lasing due to a self-terminating transition of the calcium atom in a hollow-cathode discharge

An investigation was made of the characteristics of lasing due to the self-terminating 4p¹P₁–3d¹D₂ transition of the calcium atom (λ = 5.544 μ) in a quasisteady-state hollow-cathode discharge. The maximum laser output power was 10.5 mW, the specific laser output power being not less than 30 mW/cm³. This was roughly a factor of 30 greater than the specific laser output power realized by exciting calcium vapor in the positive column of a discharge. The experimental results obtained were used to estimate the active-medium efficiency η_am = 0.21–0.59% and the gain κ≥0.36 cm^–1.