Electromagnetically Induced Transparency and Fano Resonances in Waveguides and U-shaped or Cross-shaped Resonators

Abstract

In this paper, we study one-dimensional (1D) integrated photonic systems composed of waveguides connected to resonators.We explain and discuss the appearance of two unique resonance phenomena: Fano transparency and electromagnetically induced transparency (EIT).These resonances play a crucial role in optimizing signal filtering in photonic devices.Our study focuses on two geometrical configurations: a cross-shaped arrangement with collocated lateral resonators at the same site and a U-shaped configuration with resonators positioned at different sites.We use Transfer Matrix Method (TMM) to analyze these configurations, improving existing theoretical models for photonic waveguide systems.Using this method, we can manipulate the geometrical parameters of resonators to fine-tune the transmission properties associated with the Fano and EIT resonances.Our results indicate that symmetrical resonators eliminate Fano resonance in cross-shaped structures, while the introduction of asymmetrical resonators induces their emergence.For U-shaped structures, we demonstrate the presence of Fano and EIT resonances, and show that their manifestation depends on the geometric parameters of the resonators.Our research has two major implications: Firstly, it advances the theoretical knowledge of resonance phenomena in photonic waveguides.Secondly, it provides a methodology for the design of photonic structures with adapted transmission characteristics, opening the way to applications in advanced signal processing technologies.