Spatio-temporal characterization of ultrashort laser beams: a tutorial

International audienceThe temporal characterization of ultrafast laser pulses has become a cornerstone capability ofultrafast optics laboratories and is routine both for optimizing laser pulse duration and designingcustom fields. Beyond pure temporal characterization, spatio-temporal characterization providesa more complete measurement of the spatially-varying temporal properties of a laser pulse.These so-called spatio-temporal couplings (STCs) are generally nonseparable chromaticaberrations that can be induced by very common optical elements—for example, diffractiongratings and thick lenses or prisms made from dispersive material. In this tutorial we introduceSTCs 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 ofspatio-temporal characterization techniques with a view to mention most techniques, but also toprovide greater details on a few chosen methods. The goal is to provide a reference and acomparison of various techniques for newcomers to the field. Lastly, we discuss nuances ofanalysis and visualization of spatio-temporal data, which is an often underappreciated andnon-trivial part of ultrafast pulse characterization