Repetitively pulsed, 70-J photolytic iodine laser with excellent optical and long/reliable operation

The performance of a repetitively pulsed, 70 joule, closed cycle 1.3 /spl mu/M photolytic atomic iodine laser with excellent beam quality (BQ=1.15) is presented. This BQ was exhibited in the fundamental mode from a M=3.1 confocal unstable resonator at a 0.5 Hz repetition rate. A closed cycle scrubber/laser fuel system consisting of a condensative-evaporative section, two Cu wool I/sub 2/ reactor regions, and an internal turbo-blower enabled the laser to operate very reliably with low maintenance. The fuel system provided C/sub 3/F/sub 7/I gas at 10-60 torr absent of the photolytic quenching by-product I/sub 2/. Using a turbo-molecular blower longitudinal flow velocities greater than 10 m/s were achieved through the 150 cm long by 7.5/spl times/7.5 cm/sup 2/ cross sectional photolytic iodine gain region. In addition to the high laser output and excellent BQ, the resulting 8-12 /spl mu/s laser pulse had a coherence length greater than 45 meters and polarization extinction ratio better than 100:1. Projections from this pulsed photolytic atomic iodine laser technology to larger energies, higher repetition rates, and variable pulse widths are discussed.<
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