Development of experimental setups to study single molecules and condensation at the molecular level

This talk will be divided into three parts. In the first, I will present our efforts to build an instrument operating at cryogenic temperatures to make high-resolution spectroscopic measurements on isolated and "complex" molecules in the harmonic range. The facility currently combines a buffer gas cooling chamber and a ring cavity/reinforced cavity spectrometer (CRDS-CEAS).
In the second part, I will present our work on water-containing van der Waals complexes probed with the CW-CRDS for neutral complexes. The focus will be on H2O-CO2 and our efforts to produce larger mass-selected aggregates.
Finally, I will present measurements we have made to characterize the lifetime of water droplets in air using a new method based on Mie scattering measurements. This last study was motivated by papers published in the context of the COVID-19 pandemic and led us to explore the field of mass photometry.