Prepulsing of laser-produced plasmas for more efficient pumping of extreme-ultraviolet lasers

We have used a low-energy prepulse to enhance the soft-x-ray emission of laser-produced plasmas in a parameter range that has been used to pump photoionization lasers. We have prepulsed a laser-produced-plasma-pumped Xe iii 109-nm laser, which was pumped with an 80-ps 1064-nm pulse, and we observed a greater than tenfold increase in output.