Dispersion-free monochromatization method for selecting a single-order harmonic beam

TL;DR

This paper introduces a multilayer mirror-based method to select a single high harmonic order from multiple orders, maintaining pulse duration and broad tunability, advancing ultrafast soft x-ray experiments.

Contribution

The authors present a novel multilayer mirror design that achieves dispersion-free monochromatization of high harmonic beams, enabling efficient single-order selection with broadband tunability.

Findings

Realizes perfect extraction of a single harmonic order

Maintains femtosecond to attosecond pulse durations

Offers broadband tunability and high reflectivity

Abstract

We propose a method to monochromatize multiple orders of high harmonics by using a proper designed multilayer mirror. Multilayer mirrors designed by our concept realize the perfect extraction of a single-order harmonic from multiple-order harmonic beam, and exhibit broadband tenability and high reflectivity in the soft-x-ray region. Furthermore, the proposed monochromatization method can preserve the femtosecond to attosecond pulse duration for the reflected beam. This device is very useful for ultrafast soft x-ray experiments that require high-order harmonic beams, such as femtosecond/attosecond, time-resolved, pump-probe spectroscopy.