A Cavity-Enhanced Spectroscopist's Lens on Molecular Polaritons

Polariton chemistry has been hailed as a potential new route to direct molecular processes with electromagnetic fields. To make further strides, it is essential for the community to clarify which unusual polaritonic phenomena are true hallmarks of cavity quantum electrodynamics and which can be rationalized with classical optical physics. Here, we provide a tutorial perspective on the formation, spectroscopy, and behavior of molecular polaritons using classical optics. Where possible, we draw connections to cavity-enhanced spectroscopy and recast open questions in terms that may be more familiar to the broader community of physical chemists.