Finite size effects on one dimensional coupled cavity optical waveguides

Abstract

The properties of an infinite periodic coupled cavity optical waveguide are completely determined by the tight binding parameter κ. One dimensional finite size coupled cavity optical waveguide (FSCCOW) structures, which are specified by the cavity number, substrate and covering layers, are investigated using transfer matrix method in this paper. Our results show that the envelope functions of the local minima and maxima in the transmission spectrum are invariant with respect to the cavity number, and the envelopes of the group velocity spectrum do not converge to each other with the increasing of cavity number. These results allow us better understand the asymptotic behaviors of FSCCOWs on increasing cavity number. We also study the impact of the substrate and covering layers on the shape of the envelope functions, and find that the quasiflat ranges shift sensitively from the band center to the band edges when the thickness of the content layers in the substrate layers and covering layers are changed slightly.