Topological resonances in a Möbius ring resonator

Abstract A Möbius strip, fascinating for its unique topological property of being a one-side nonorientable surface, has inspired mathematicians, physicists, engineers, and artists many centuries. In coherent system, waves on the surfaces reveal rich dynamics due to interplay coherence topology. Here we experimentally observe resonances in ring resonator formed twisted optical fiber loop. The polarization-maintaining encourages hybridization two polarization states, giving rise crucial Berry phase. This geometrical phase leads frequency shifts resonant modes with non-trivial fractional mode number. Moreover, are topological, only resonating certain polarized circular chirality. These features introduce factors into wave resonances, paving way information processing quantum information, dynamics.