Reversible fast to slow-light transition originating in the optical analog of EIA-EIT transformation in optical resonators

Abstract

Coupled-resonator-induced transparency (CRIT) and coupled-resonator-induced absorption (CRIA) are the all-optical analogs of electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA), and enable an optical pulse to propagate subluminally and superluminally in integrated photonic systems, respectively. Here, we describe the results of a theoretical study, which reveals a reversible CRIA-CRIT transition using coupled optical ring resonators. Analogous to the dispersion reversal occurring in the EIA-EIT transition, the dispersion also reverses during the CRIA-CRIT transition. Besides the EIA-EIT crossover analogy, we describe additional analogs of the coherent atomic phenomena arising in the CRIA-CRIT transition. We also discuss the specific conditions that lead to strongly enhanced dispersion. Furthermore, in contrast to the previous studies on coupled resonators, we reveal acquiring a critically and undercoupled slow-light CRIT from an overcoupled fast-light CRIA. Our experimentally viable study provides a route for the dynamic control and reversal of dispersion, which, among other, is important for quantum information technology, the Fresnel light dragging effect, temporal cloaking, and enhanced performance of the optical devices.