Demonstration of high-repetition-rate tabletop soft-x-ray lasers with saturated output at wavelengths down to 13.9 nm and gain down to 10.9 nm

Saturated tabletop lasers operating at 5 Hz repetition rate with average powers > 1 mu W were demonstrated at wavelengths between 16.5 and 13.9 nm in the 4d S-1(0)-4p P-1(1) transitions of Ni-like ions. The results were obtained using picosecond laser heating pulses with an energy of only 1 J by optimizing the angle of incidence for maximum energy deposition. Lasing was also observed for shorter wavelength transitions of the same isoelectronic sequence, with amplification in the 11.9 nm line of Ni-like Sn approaching gain saturation, and progressively reduced gain for wavelengths as low as 10.9 nm for Ni-like Te. These high repetition rate soft x-ray lasers will enable new applications in science and the development of unique metrology and processing tools for industry.