While high harmonic x-ray sources are well established sources for ultrafast spectroscopy, the decrease in efficiency towards higher energies limits their application. Here, a loose-focused, TW mid-IR laser is used to generate high harmonic soft x-rays with pulse energies of a few nJ in the water window and easy energy scaling.
- Yuxi Fu
- Kotaro Nishimura
- Eiji J. Takahashi
