Cavity Ring-Down Spectroscopy
Summary
In the Cold Atom Nanophotonics group a Bose-Einstein condensate of photons is being realized using a dye-filled microcavity. One key element of this experiment is the high reflectivity of the mirrors forming the microcavity.
In this thesis we report on cavity ring-down spectroscopy. This technique was used to measure the reflectivity for a set of identical high reflectivity mirrors from CRD Optics. For wavelengths ranging from 560 nm to 580 nm, we measured reflectivities of R~99.8%. This is a factor 1000 less reflective than the expected reflectivity of R=99.9998%. We review factors which could contribute to this difference, most noteworthy being the cleanliness of the mirrors.