# Advances in high-order harmonic generation sources for time-resolved investigations

## TL;DR

This paper reviews recent developments in high-harmonic generation sources, focusing on their application in time-resolved spectroscopy with attosecond pulses, highlighting new infrastructure and techniques.

## Contribution

It provides a comprehensive overview of experimental and theoretical advances in high-harmonic generation for attosecond science, including upcoming infrastructure developments.

## Key findings

- Discussion of experimental and theoretical works in high-harmonic generation
- Introduction of the Extreme Light Infrastructure Attosecond Light Pulse Source
- Potential for new time-resolved investigations at attosecond timescales

## Abstract

We review the main research directions ongoing in the development of high-harmonic generation-based extreme ultraviolet sources for the synthesization and application of trains and isolated attosecond pulses to time-resolved spectroscopy. A few experimental and theoretical works will be discussed in connection to well-established attosecond techniques. In this context, we present the unique possibilities offered for time-resolved investigations on the attosecond timescale by the new Extreme Light Infrastructure Attosecond Light Pulse Source, which is currently under construction.