Characterization of single layer anti-reflective coatings for bolometer-based rare event searches

Combining analysis from phonon signals and photon signals is a powerful technique for reducing backgrounds in bolometer-based rare event searches. Anti-reflective coatings can significantly increase the performance of the secondary light-sensing bolometer in these experiments. As a first step toward these improvements, coatings of SiO$_2$, HfO$_2$, and TiO$_2$ on Ge and Si wafers were fabricated and characterized at room temperature and multiple angles of incidence.