High-order harmonic generation in X-ray range from laser induced noble gas multivalent ions

TL;DR

This paper demonstrates a low-cost, compact method for generating high-energy X-ray photons (~5.2 keV) via high-order harmonic generation in noble gas ions, enabling accessible attosecond physics research.

Contribution

It introduces a novel approach using near-infrared laser interaction with krypton ions to produce the highest photon energy from high-order harmonic generation to date.

Findings

Achieved ~5.2 keV photon energy spectrum.

Demonstrated high-order harmonic generation in noble gas ions.

Reduced experimental complexity for multi-keV X-ray production.

Abstract

Sub-femtosecond x-ray burst is powerful tool for probing and imaging electronic and concomitant atomic motion in attosecond physics. For years, x-ray source (above 2 keV) had mainly been obtained from X-ray free electron laser (XFEL) or synchrotron radiation, which are high energy consumption, high cost and huge volume. Here we propose a low-cost and small-size method to generate X-ray source. We experimentally obtained high photon energy spectrum (~ 5.2 keV) through both atom and multiple valence state ions using a near-infrared 1.45 {\mu}m driving laser interacting with krypton gas, according to our knowledge, which is the highest photon energy generated through high-order harmonic generation up to now. In our scheme, multi-keV photon energy can be achieved with a relaxed requirement on experimental conditions, and make time-resolved studies more accessible to many laboratories that are capable of producing high energy photon extending to hard x-ray region. Furthermore, our scheme minimizes the influence of X-ray fluorescence process on detection, and can also be utilized to study the quantum-optical nature of high-order harmonic generation.