High average power, high repetition rate table-top soft x-ray lasers for applications in nanoscience and nanotechnology

There is great interest in table-top sources of bright coherent soft x-ray radiation for nanoscale applications. We report the demonstration of a compact, high repetition rate soft x-ray laser operating at wavelengths between 10.9nm to 18.9nm, including the generation of 0.15mW average power at $\lambda =$18.9nm and 0.1mW average power at $\lambda =$13.9nm. These short wavelength lasers were driven by an all diode pumped, chirped pulse amplification laser based on cryogenically-cooled Yb:YAG amplifiers that produces 1 Joule, picosecond duration pulses at 100 Hz repetition rate. Irradiation of solid targets results in the production of plasmas with large transient population inversions on the 4d$^{\mathrm{1}}$S$_{\mathrm{0}}\to $4p$^{\mathrm{1}}$P$_{\mathrm{1}}$ transition of Ni-like ions. Optimization of this high repetition rate laser combined with the development of high shot capacity, rotating targets has allowed the uninterrupted operation of this soft x-ray laser for hundreds of thousands of consecutive shots, making it suitable for a number of applications requiring high photon flux at short wavelengths. Work was supported by the NSF ERC for Extreme Ultraviolet Science and Technology using equipment developed under NSF Award MRI-ARRA 09-561, and by the AMOS program of the Office of Basic Energy Sciences, US Department of Energy.