Incident Light Influence on the Transmission of Coupled Ring Resonators

The transmission matrix method is used to analyze the influence of incident light on coupled resonators. Two different types of incident light on the same coupled resonator geometry are shown to lead to different system transmission features. The EIT-like phenomenon occurs in the type Ⅰ case with the transmission being symmetric around the zero-single-pass-phase-shift frequency. In the type Ⅱ case the resonant frequency has a blue shift corresponding to the increasing coupling strength between the two ring resonators. Also, the critical-coupling-like condition exists in the type Ⅱ configuration to maintain the zero-single pass-phase-shift frequency. The incident light, as well as the geometry, partially determine the mode interference in the coupled ring resonator system.