Characteristics of defect modes in side-coupled and mutually coupled microresonator arrays

Abstract

We present both theoretically and experimentally the existence of defect modes in side-coupled and mutually coupled microresonator arrays. The qualitative difference between the two types of defect modes is investigated. The Q factor of both defect modes for varying defect sizes is characterized, and an enhancement of ∼30× relative to individual loaded resonators is demonstrated. The defect modes are then compared with coupled resonator–induced transparency (CRIT), indicating that the defect modes based on side-coupled microresonator arrays are actually the extension of the CRIT resonance in two-resonator structures.