Precision spectroscopy of light atoms as tests of QED and development of nuclear structure theory

We report on recent high-precision spectroscopy of light elements, specifically beryllium and oxygen. For beryllium, we present updated results on the absolute transition frequencies of the 2s2p ³P°_J → 2s4s ³S₁ triplet transitions. For oxygen, we report absolute frequencies for multiple transitions, as well as isotope shift measurements of the 3s ⁵S°₂ → 3p ⁵P_J transitions in the stable isotopes. The oxygen isotope shifts will serve as reference data for upcoming measurements of the isotope shifts and hyperfine structure of neutron-rich oxygen isotopes.