On the nonreciprocal propagation of light waves in asymmetric lossy system of thin films

TL;DR

This paper demonstrates that nonreciprocal light propagation can occur in passive, asymmetric, lossy thin film systems without the need for electromagnetic coupling, temporal variation, or nonlinear effects, supported by theoretical and experimental validation.

Contribution

It reveals a new mechanism for optical nonreciprocity in passive asymmetric lossy systems, expanding potential applications in nonreciprocal optical devices.

Findings

Nonreciprocal propagation observed in asymmetric lossy thin films.

Theoretical analysis aligns with experimental results.

Passive systems can exhibit nonreciprocity without nonlinear effects.

Abstract

Optical nonreciprocity is the phenomenon where light behaves differently when traveling in the forward direction compared to the backward direction. This nonreciprocal behavior is typically achieved in systems that exhibit electromagnetic coupling, temporal variation, and nonlinear properties. In this work, we demonstrate that nonreciprocal behavior can also exist in an optically asymmetric lossy system without requiring these conditions. In our study, we theoretically investigate the nonreciprocal propagation of light waves in a passive asymmetric optical system made from a thin film that experiences some losses. Our theoretical analysis has been experimentally validated. This type of system can be utilized in passive nonreciprocal devices.