Spatio-temporal characterization of ultrashort laser beams: a tutorial

TL;DR

This tutorial provides a comprehensive overview of spatio-temporal characterization of ultrashort laser pulses, explaining the underlying concepts, common techniques, and data analysis methods to aid researchers in the field.

Contribution

It offers a detailed introduction to spatio-temporal couplings, reviews various characterization techniques, and discusses data analysis and visualization strategies for ultrafast laser pulses.

Findings

Overview of spatio-temporal couplings and their origins

Comparison of multiple characterization techniques

Guidance on data analysis and visualization methods

Abstract

The temporal characterization of ultrafast laser pulses has become a cornerstone capability of ultrafast optics laboratories and is routine both for optimizing laser pulse duration and designing custom fields. Beyond pure temporal characterization, spatio-temporal characterization provides a more complete measurement of the spatially-varying temporal properties of a laser pulse. These so-called spatio-temporal couplings (STCs) are generally nonseparable chromatic aberrations that can be induced by very common optical elements -- for example diffraction gratings and thick lenses or prisms made from dispersive material. In this tutorial we introduce STCs and a detailed understanding of their behavior in order to have a background knowledge, but also to inform the design of characterization devices. We then overview a broad range of spatio-temporal characterization techniques with a view to mention most techniques, but also to provide greater details on a few chosen methods. The goal is to provide a reference and a comparison of various techniques for newcomers to the field. Lastly, we discuss nuances of analysis and visualization of spatio-temporal data, which is an often underappreciated and non-trivial part of ultrafast pulse characterization.