In this talk, I willdiscuss my lab’s efforts to harness optical enhancement cavities both as aplatform to explore molecular physics under strong light-matter interactionsand as tools for precision spectroscopy.

Polaritons are hybridlight-matter states with unusual properties that arise from strong interactionsbetween a molecular ensemble and the confined electromagnetic field of anoptical cavity. Cavity-coupled molecules appear to demonstrate energetics,reactivity, and photophysics dramatically distinct from their free-spacecounterparts, but the mechanisms and scope of these phenomena remain uncertain.I will discuss our new experimental platforms to investigate molecular dynamicsunder strong coupling. In one thrust, we are engineering polariton formation incold gas-phase molecules, where attaining sufficiently strong light-matterinteractions is a challenge and had not been previously reported. We areharnessing this infrastructure as a testbed to study fundamental polariton photophysicsand chemistry. We are also searching for signatures of cavity-altered dynamicsin benchmark condensed-phase systems using ultrafast transient absorption spectroscopywith the goal of better understanding exactly how and when reactivetrajectories may be influenced by strong light-matter interactions.

I will also discuss ourefforts in cavity-enhanced spectroscopy of complex molecular systems. Cavity-coupledfrequency comblasers enable simultaneously high-resolution, high-sensitivity, broadband, andrapid-acquisition spectroscopic measurements. We are using cavity-enhancedfrequency comb spectroscopy to reveal the structure and behavior ofastrochemically-relevant molecules and clusters. We are also extending thesetechniques towards the study of atmospherically-relevent aerosols.