Browsing by Author "Cheng, S. -C."

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Tight-binding theory for coupled photonic crystal waveguides
(2007-03-01)
Chien, F. S. -S
;
Tu, J. B.
;
Hsieh, W. -F.
;
Cheng, S. -C.
;
光電工程學系
The point-defect coupling under the tight-binding approximation is introduced to describe the behavior of dispersion relations of the guided modes in a single photonic crystal waveguide (PCW) and two coupled identical PCWs. The cross-coupling coefficient beta of a point defect in one PCW to the nearest-neighboring (NN) defect in the other PCW causes the split of the dispersion curves, whereas the cross-coupling coefficient gamma to the next-NN defects causes a sinusoidal modulation to the dispersion curves. Furthermore, the sign of beta determines the parities of the fundamental guided modes, which can be either even or odd, and the inequality parallel to beta parallel to