UV lasing in a multipass copper vapour amplifier – nonlinear crystal system

A UV-radiation source based on a single-stage multipass copper-vapour laser amplifier and a nonlinear DKDP crystal is discussed. The peak pulse power of the laser radiation at the nonlinear crystal input was enhanced considerably by using a special design of the multipass amplifier, resulting in efficient lasing at the sum frequency (at 0.271 μm) of the 0.51-μm and 0.578-μm copper lines.