Gain and saturation of the atomic fluorine laser

Abstract

In this work a dilute fluorine plasma pumped by the ion-ion recombination of H+2 and F− has been operated as a pulsed amplifier. Two synchronously excited plasmas were produced by preionized discharges in an atmospheric electrical avalanche device switched by hydrogen thyratrons. Two principal outputs having wavelengths of 745 and 635 nm were obtained from the tube serving as an oscillator. These were dispersed so that they could be individually threaded through the second discharge. Calibrated attenuation of the beam from the oscillator subsequently injected into the amplifier provided data on the overall amplification ratio. From these data effective saturation intensities of 1.2 and 4.5 kW/cm2 were found for the transitions at 745 and 635 nm, originating on the 3p4P05/2 and 3p4S03/2 states of F*, respectively. Corresponding small signal gains were found to be extremely high, reaching 0.44 and 0.31 cm−1, for the two transitions, respectively.