Optimal stimulated emission conditions in an He–Ne laser utilizing the 3p4–2s2 Ne (2.4 μm) transition

The output power due to the 3p₄–2s₂ lasing transition depended strongly on the He–Ne mixture composition. This was because trapping of resonance radiation from the 2s₂ level by the ground state influenced the inversion due to this transition. The absolute output power (0.15 mW) was determined for optimal compositions and pressures of the He–Ne mixture and an optimal exit mirror reflection coefficient. Measurements were made of the active medium gain (0.014 cm ^– 1). Under optimal conditions, stable lasing due to the selected transition could be achieved in a compact laser with a high excess over the threshold and an output power sufficient for this laser to be used to analyze the HF content in the atmosphere.