Gain, saturation, and optimization of the XeF discharge laser

Abstract

In this work a xenon-F2 plasma diluted in helium has been operated as a pulsed amplifier for the B→X transition of XeF. Two synchronously excited plasmas were produced by preionized discharges in atmospheric electrical avalanche devices switched by hydrogen thyratrons. The principle output obtained at 352 nm from the tube serving as an oscillator was optically delayed and then was threaded through the second discharge. Calibrated attenuation of this beam injected into the amplifier provided data on the overall amplification ratio. From these data effective saturation intensities of 620 and 860 kW/cm2 were found for operation at pressures of 2.7 and 3.7 atmospheres, respectively. Corresponding small signal gains were found to be moderately high, reaching 0.11 and 0.13 cm−1, for the two conditions, respectively. Based upon these results for the gain and saturation parameters, a self-excited oscillator was designed to be optimized simultaneously for energy density and efficiency. By matching the ringing time of the driving circuit to the characteristic time of the discharge a XeF device was realized which produced 10-ns output pulses representing an energy density of 2.7 J/liter and an efficiency relative to storage of 1.6%.