Attosecond broadband multilayer mirrors for the water window spectral range

Abstract

Recent advances in the development of attosecond soft X-ray sources ranging into the ‘water window’ spectral range, between the carbon 1s and oxygen 1s states (284 eV - 543 eV), are also driving the development of suited broadband multilayer optics for attosecond beam steering and dispersion management. The relatively low intensity of current High Harmonic Generation (HHG) soft X-ray sources calls for an efficient use of photons, thus the development of low-loss multilayer optics is of uttermost importance. Here, we report about the realization of atomically smooth interfaces in broadband CrSc multilayer mirrors by an optimized ion beam deposition and assisted interface polishing process.