Thirty-five photons (

m) per photolytic F atom have been obtained from a 40-cm
3photochemical laser filled with 400 torr of F
2, 100 torr of H
2, and minor amounts of Ar and O
2mixed at 300 K. With 0.035-percent dissociation of the F
2, 0.83-J 250-ns full width at half maximum (FWHM) pulses were observed.