High-order parametric generation of coherent XUV radiation

Extreme ultraviolet (XUV) radiation finds numerous applications in spectroscopy. When the XUV light is generated via high-order harmonic generation (HHG), it may be produced in the form of attosecond pulses, allowing access to unprecedented ultrafast phenomena. However, the HHG efficiency remains limited. Here we present an observation of a new regime of coherent XUV emission which has a potential to provide higher XUV intensity, vital for applications. We explain the process by high-order parametric generation, involving the combined emission of THz and XUV photons, where the phase matching is very robust against ionization. This introduces a way to use higher-energy driving pulses, thus generating more XUV photons. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

A new regime of coherent XUV emission has been observed, showing potential for higher XUV intensity crucial for applications. The study explains the process of high-order parametric generation, involving the combined emission of THz and XUV photons with robust phase matching against ionization. This provides a way to use higher-energy driving pulses for generating more XUV photons.