Spinning indirectly coupled optical resonators

A spinning optical resonator is an excellent platform for realizing nonreciprocity. Here, we demonstrate the distinctive isolation features in spinning indirectly coupled resonators, where the nonreciprocal light propagation and probing mechanism via mechanical rotation have been achieved. Interplay with nanoparticles induces a tunable one- or two-way transmission through differential rotation, which can also be employed to realize the improved capability of particle detection. By pushing an individual resonator into a rotation-induced exceptional point (EP) condition, an EP associated isolation pattern is observed with avoided crossing. Our results may promote the development and understanding of nonreciprocity, rotation devices and anti-parity-time symmetry.