Electromagnetically Induced Transparency and Absorption in Directly Coupled Whispering-Gallery Mode Microcavities

Xu Huang,Chuan Wang,Tie-Jun Wang

doi:10.1109/jphot.2022.3151506

Abstract

Optical interference and the related effects are key elements which could exhibit the properties of both classical and quantum optical systems. Usually, the interference between different optical paths may produce intriguing effects, such as the electromagnetically induced transparent (EIT) and so on. In this work, we study the interference effects in directly coupled whispering-gallery mode (WGM) micro-resonators, in which the emergence of EIT and electromagnetically induced absorption (EIA) could be observed. We find by tuning the coupling strength between the resonators, the modulation phase may control the appearance and disappearance of EIT (EIA). Furthermore, we prove the existence of fast and slow light, and propose a scheme for effective switching between them. This work provides a new strategy for obtaining slow light and quantum storage in the WGM micro-resonators.

Highlights

O PTICAL interference is a typical effect in both classical and quantum optics
electromagnetically induced transparent (EIT) or electromagnetically induced absorption (EIA) can be obtained by tuning the coupling strength and phase control of the resonator, which provides a new method for obtaining slow light [89], ground state cooling [90], second-harmonic generation [91] and quantum storage [92]
It is worth mentioning that near the phase θ = 1.515π, when the coupling strength is κ = 23.7MHz and κ = 167.8MHz, the group delay is with the opposite sign, which means that the slow-to-fast and fastto-slow light effects can emerge by changing the coupling strength.Compared with the slow light in the classic EIT [99], [100], the group delay of our slow light has improved by nearly an order of magnitude, and we have studied the fast light effects in the system

Summary

INTRODUCTION

O PTICAL interference is a typical effect in both classical and quantum optics. And it has been widely demonstrated in nanophotonic devices, such as in the plasmonic devices and optical microcavities. In the WGM optical microcavities, the resonant light field is restricted by the total internal reflection and circulates around the curved inner boundary of the optical microcavities This special architecture can greatly enhance the light-matter interactions due to the high quality factor. The coupled resonator induced transparency and absorption caused by the interference between the WGM microcavities is demonstrated [87]. The transparency and absorption of chiral light state modulation at anomalous points in an indirect coupled resonator system is discussed [88] From these results, EIT or EIA can be obtained by tuning the coupling strength and phase control of the resonator, which provides a new method for obtaining slow light [89], ground state cooling [90], second-harmonic generation [91] and quantum storage [92]. We believe this work may provide a new strategy for the fast or slow light generation and switching in the nanophotonic system

THEORETICAL MODEL

RESULTS AND DISCUSSIONS

SUMMARY