A self-contained coupled-mode theory for the coupled two asymmetric photonic crystal waveguides (PCWs) is presented. The first-order coupled-mode equations are derived under a weak coupling assumption. The coupling coefficients are obtained systematically by a matrix calculus using the modal solutions of each PCW in isolation. The coupled-mode equations are solved for contra-directional coupling between two asymmetric PCWs formed by a hexagonal lattice of circular air holes in a dielectric medium. The power transmission spectra at different output ports of the coupled PCWs are investigated. It is shown that the self-contained coupled-mode analysis is useful to characterize a peculiar feature of the contra-directionally coupled PCWs as a drop filter.
© 2014 Optical Society of America
Original Manuscript: November 25, 2013
Manuscript Accepted: December 21, 2013
Published: February 13, 2014
Vakhtang Jandieri, Kiyotoshi Yasumoto, and Jaromir Pistora, "Coupled-mode analysis of contra-directional coupling between two asymmetric photonic crystal waveguides," J. Opt. Soc. Am. A 31, 518-523 (2014)