Development of optical absorption sensors for geochemistry and earth sciences applications

In this talk, I will introduce the fundamentals of highly sensitive optical techniques based on absorption spectroscopy and resonant cavities (among others) for measuring gas composition — including both concentrations and isotopic signatures. These methods have a wide range of applications in geochemistry and Earth sciences, from the detection of atmospherically relevant trace species, with a focus on reactive molecules, to the in-situ measurement of dissolved gases and water isotopes, and the laboratory analysis of air bubbles trapped in ice. I will present recent developments from our group and illustrate how these instruments are applied to address key scientific questions.