Modern Physics Letters B
THEORETICAL STUDY OF TRANSMISSION SPECTRUM IN CAVITY-WAVEGUIDE SIDE-COUPLED SYSTEMS
Chuanbo Dong, Tao Wang, Wei Yan, Xiaoming Li
Abstract
Starting with one-cavity side-coupled with waveguide system, we theoretically study on transmission spectrum for a two-cavity side-coupled with waveguide system based on coupled mode theory by using light-tracing method. Interesting effects called all-optical analog to EIT appear in some cases. 3D finite-difference time-domain (FDTD) method provides optical modes distributions at different wavelengths, including the EIT-like wavelength. Influences of different parameters on the narrow EIT-like peak such as cavity quality factors Q, frequency difference detuning Δω, and phase difference detuning between cavities ΔΦ are discussed. Compared with previous studies, this method is easier to understand and can be used as a model for both standing cavities like line-defect photonic crystal cavities and whispering gallery modes cavities like microring cavities.