Self-focusing of laser radiation in molecular gases

Self-focusing and self-defocusing of CO₂ laser pulses of 1.6 to 80 nsec duration was observed in SF₆ gas for several lines in the 10P branch. It was observed that self-focusing depends on the vibrational excitation of the molecules and on their distribution function. This new self-focusing mechanism may be useful for propagation of high-power laser radiation in the atmosphere.