The Physics department at BHSU has created a state-of-the-art spectroscopy laboratory for ongoing research in association with the Sanford Underground Lab. The spectroscopy lab is building a custom Cavity Ring-Down Spectroscopy system for detecting very low levels of chemical impurities in Argon gas. This gas will be employed as the detection medium in future dark matter experiments in Lead, SD at the Sanford Underground Research Facility (SURF).