IDENTIFICATION OF WATER-VAPOR LASER LINES

Abstract

Twenty five laser lines in water vapor are identified as transitions between known vibration‐rotation levels. The mechanism is discussed: The initiating factor is a weak perturbation involving close resonance between levels of the bending overtone and the stretching fundamentals. Three resonances account for most of the strongest lines: 020, 5₅₀ ↔ 100, 5₁₄, at 4050 cm⁻¹, 020, 6₆₁ ↔ 001, 6₃₃, at 4408 cm⁻¹, and 020, 8₄₄ ↔ 100, 8₀₈ at 4387 cm⁻¹ above the zero level. The 2527952.8 MHz line is assigned to 001, 6₄₂ → 020, 6₆₁.