  Cold Rydberg atoms are a promising platform for quantum technologies and
combining them with optical waveguides has the potential to create robust
quantum information devices. Here, we experimentally observe the excitation of
cold rubidium atoms to a large range of Rydberg S and D states through
interaction with the evanescent field of an optical nanofiber. We develop a
theoretical model to account for experimental phenomena present such as the AC
Stark shifts and the Casimir-Polder interaction. This work strengthens the
knowledge of Rydberg atom interactions with optical nanofibers and is a
critical step toward the implementation of all-fiber quantum networks and
waveguide QED systems using highly excited atoms.
