Coherent resonant transmission

TL;DR

This paper investigates how intra-resonator intermodal coupling affects reflectionless coherent light transport in coupled resonator arrays, enabling controlled mode conversion and advancing integrated photonics.

Contribution

It reveals the constructive role of intra-resonator intermodal coupling in achieving coherent resonant transmission and mode switching, a novel insight for photonic control.

Findings

Intra-resonator intermodal coupling facilitates reflectionless transmission.

Superposition coefficients determine mode chirality of transmission.

Time-reversal and CRT enable perfect mode conversion.

Abstract

The reflectionless coherent light transport in the coupled resonator array is investigated in the presence of intra-resonator intermodal coupling between the clockwise and counterclockwise modes, which plays a constructive role for modulating the light flow rather than inducing the unwanted backscattering. The interplay between the intra-resonator intermodal coupling and the inter-resonator couplings enables the coherent resonant transmission (CRT) of the properly superposed injection constituted by the clockwise and counterclockwise modes. The superposition coefficients of the initial excitation determine the mode chirality of the resonant transmission. Sequentially experiencing the time-reversal process of CRT and the CRT realizes the perfect mode conversion that the mode chirality of the injection wave switches into the opposite after resonant transmission. Our findings on the coherent light transport provide insights for the control and manipulation of light field in the integrated photonics, nanophotonics, chiral optics, and beyond.