XUV Frequency Combs via Femtosecond Enhancement Cavities

TL;DR

This paper reviews advances in tabletop XUV sources using femtosecond enhancement cavities, highlighting their high flux, repetition rate, and spectral coverage, enabling precision spectroscopy and future scientific applications.

Contribution

It provides a comprehensive review of the state-of-the-art in XUV frequency comb generation via femtosecond enhancement cavities, including recent technical developments and challenges.

Findings

Generation of 10^14 photons/sec in XUV

High repetition rates over 50 MHz

Spectral coverage from 40 nm to 120 nm

Abstract

We review the current state of tabletop extreme ultraviolet (XUV) sources based on high harmonic generation (HHG) in femtosecond enhancement cavities (fsEC). Recent developments have enabled generation of high photon flux (1014 photons/sec) in the XUV, at high repetition rates (>50 MHz) and spanning the spectral region from 40 nm - 120 nm. This level of performance has enabled precision spectroscopy with XUV frequency combs and promises further applications in XUV spectroscopic and photoemission studies. We discuss the theory of operation and experimental details of the fsEC and XUV generation based on HHG, including current technical challenges to increasing the photon flux and maximum photon energy produced by this type of system. Current and future applications for these sources are also discussed.