Nonreciprocal light propagation induced by a subwavelength spinning cylinder

Abstract

Nonreciprocal optical devices have broad applications in light manipulations for communications and sensing. Non-magnetic mechanisms of optical nonreciprocity are highly desired for high-frequency on-chip applications. Here, we investigate the nonreciprocal properties of light propagation in a dielectric waveguide induced by a subwavelength spinning cylinder. We find that the chiral modes of the cylinder can give rise to unidirectional coupling with the waveguide via the transverse spin-orbit interaction, leading to different transmissions for guided wave propagating in opposite directions and thus optical isolation. We reveal the dependence of the nonreciprocal properties on various system parameters including mode order, spinning speed, and coupling distance. The results show that higher-order chiral modes and larger spinning speed generally give rise to stronger nonreciprocity, and there exists an optimal cylinder-waveguide coupling distance where the optical isolation reaches the maximum. Our work contributes to the understanding of nonreciprocity in subwavelength moving structures and can find applications in integrated photonic circuits, topological photonics, and novel metasurfaces.

14 pages, 6 figures

References in corpus (8)

• Quantum spin Hall effect of light
• Chiral nanophotonic waveguide interface based on spin-orbit coupling of light
• Photonics of Time-Varying Media
• Quantum optical circulator controlled by a single chirally coupled atom
• Noiseless nonreciprocity in a parametric active device
• Rotating optical microcavities with broken chiral symmetry
• Optical isolation induced by subwavelength spinning particle via spin-orbit interaction
• Robust exceptional point of arbitrary order in coupled spinning cylinders