Observation of classical dynamical isolation in nonadiabatically modulated photonic cavities

We experimentally demonstrate the phenomenon of dynamical isolation in harmonically modulated photonic cavities. We achieve this by strongly modulating a fiber ring cavity at a rate much faster than its linewidth. Such a nonadiabatically modulated cavity can show complete suppression of intracavity power even for an on-resonance input, resulting in dynamical isolation of the cavity field from the input light, as predicted in a recent theoretical study by Minkov et al. [APL Photonics 2, 076101 (2017)]. This counterintuitive behavior is strikingly different from the adiabatic regime typically studied in modulated photonic cavities, where the intracavity field is enhanced when the cavity’s instantaneous resonance frequency matches the input light’s frequency. Our work shows that periodically driven photonic systems can exhibit classical versions of quantum effects such as dynamical decoupling, which rely on modulating an open system at a rate faster than the system-reservoir interaction. Such effects have applications in signal optimization and frequency conversion in integrated photonics.