Laser action at 3577 Å in proton-beam-pumped Ar-N2 mixtures

Abstract

Laser action at 3577 Å has been achieved in argon/nitrogen mixtures of 400–1140 Torr total pressure by use of an intense proton beam from a magnetically insulated diode. The threshold for laser action in 700 Torr of 75% Ar/25% N2 was ∼1.3 MW/cm3 of deposited proton beam power. Laser power increased nearly four orders of magnitude as the deposited energy was raised to 15 times the threshold value. Amplified spontaneous emission increased rapidly with a deposited proton power of ≳16 MW/cm3. A maximum laser intensity of 450 kW/cm2 (1.1 mJ for 20 nsec FWHM with a 0.12-cm2 area) was obtained, without optimization of the output coupling mirror, in 25% N2 mixtures at 1140 Torr total pressure.