Plasmon-Induced Transparency and High-Performance Slow Light in a Plasmonic Single-Mode and Two-Mode Resonators Coupled System

We investigate the plasmon-induced transparency (PIT) and slow-light properties in a plasmonic single-mode and two-mode resonators coupled system. The bare-state PIT effect originates from the destructive interference between a radiant standing-wave mode in the slot cavity and two subradiant travelling-wave modes in the ring resonator. A theoretical model is established to describe this PIT system, and the analytical results agree well with the numerical simulations. The difference between our structure and similar coupled resonators structures is shown. The transparency window can be tuned by adjusting the structural parameters, and two types of PIT lineshape are discussed in detail. The numerical results reveal that the PIT window with weakly resolved and equal doublet peaks exhibits high-performance slow light. A delay-bandwidth product larger than 1 and ultralow dispersion are obtained, and a delay of 1 bit with negligible pulse distortion is achieved in the proposed system.