  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.
