Fundamentals of heterodyne wave mixing spectroscopy: a tutorial
Daniel Groll, Thilo Hahn, Paweł Machnikowski, Tilmann Kuhn, Jacek Kasprzak, and Daniel Wigger
We provide a theoretical and experimental overview of heterodyne wave mixing spectroscopy, focusing mainly on four-wave mixing (FWM). We start with the fundamental theory of optically driven two-level systems and then provide a detailed overview of a modern heterodyne wave mixing setup, supported by theoretical modeling of the signal detection process. This tutorial is dedicated to students, young researchers, as well as experts in the field of nonlinear spectroscopy in general and FWM in particular.