Observation of rotational population transfer effect for an HF chemical laser

When a CO₂ gas absorption cell was placed within the optical cavity of a low pressure pulsed HF laser, the specific vibration- rotation line of the HF laser disappeared, which influenced both the intensity and pulse duration of the neighbouring lines. This behavior strongly depends upon the rotational population transfer in HF. By measuring the time response of this behavior, it was found that the rate constant for the rotational population transfer was in the range of 10⁷ s^-1 torr^-1 for the SF₆/H₂ lasing mixture.