Nonreciprocal Bloch Oscillations in Magneto-Optic Waveguide Arrays

TL;DR

This paper demonstrates nonreciprocal optical Bloch oscillations in magneto-optic waveguide arrays caused by transverse magnetization and index gradients, revealing asymmetric mode behavior and phase coherence effects.

Contribution

It introduces a novel mechanism for nonreciprocal Bloch oscillations using magneto-optic effects and index gradients in waveguide arrays.

Findings

Normal modes have different wavenumbers in opposite directions

Significant phase coherence differences between modes

Non-reciprocity achieved via index gradients and magnetization

Abstract

We show that nonreciprocal optical Bloch-like oscillations can emerge in transversely magnetized waveguide arrays in the presence of an effective index step between the waveguides. Normal modes of the system are shown to acquire different wavenumbers in opposite propagation directions. Significant differences in phase coherence and decoherence between these normal modes are presented and discussed. Non-reciprocity is established by imposing unequal vertical refractive index gradients at the substrate/core, and core/cover interfaces in the presence of transverse magnetization.