We report on a few-cycle laser system delivering sub-8-fs pulses with 353 μJ pulse energy and 25 GW of peak power at up to 150 kHz repetition rate. The corresponding average output power is as high as 53 W, which represents the highest average power obtained from any few-cycle laser architecture so far. The combination of both high average and high peak power provides unique opportunities for applications. We demonstrate high harmonic generation up to the water window and record-high photon flux in the soft x-ray spectral region. This tabletop source of high-photon flux soft x rays will, for example, enable coherent diffractive imaging with sub-10-nm resolution in the near future.
© 2014 Optical Society of America
Original Manuscript: June 9, 2014
Revised Manuscript: July 14, 2014
Manuscript Accepted: July 29, 2014
Published: August 29, 2014
Jan Rothhardt, Steffen Hädrich, Arno Klenke, Stefan Demmler, Armin Hoffmann, Thomas Gotschall, Tino Eidam, Manuel Krebs, Jens Limpert, and Andreas Tünnermann, "53 W average power few-cycle fiber laser system generating soft x rays up to the water window," Opt. Lett. 39, 5224-5227 (2014)