Using both the tight-binding approximation and the finite-difference time domain method, we analyze two types of coupled-resonator optical waveguide (CROW), a coupled-microdisks waveguide and a waveguide composed of coupled defect cavities in a two-dimensional photonic crystal. We find that the dispersion relation of the CROW band can be simply described by a small coupling parameter κ, and the spatial characteristics of the CROW modes remain the same as those of the single-resonator high <i>Q</i> modes. As applications of these unique properties, we demonstrate that CROW’s can be utilized in constructing waveguides without cross talk and enhance the efficiency of second-harmonic generation.
© 2000 Optical Society of America
(130.2790) Integrated optics : Guided waves
(190.2620) Nonlinear optics : Harmonic generation and mixing
(190.4360) Nonlinear optics : Nonlinear optics, devices
(230.7370) Optical devices : Waveguides
Youg Xu, Reginald K. Lee, and Amnon Yariv, "Propagation and second-harmonic generation of electromagnetic waves in a coupled-resonator optical waveguide," J. Opt. Soc. Am. B 17, 387-400 (2000)