Dispersion properties of photonic crystal coupled-cavity waveguides

In this paper, we will focus on CCW waveguides, which building block consists of a photonic crystal cavity of a moderate Q-factor, i.e., Q~103. We will show that despite increased radiation loss that cannot be avoided in the present design, a chain of more than 50 cavities can be coupled, as confirmed by both transmission experiment and near-field imaging. Moreover, formation of a smooth and continuous transmission band is observed even for structures consisting of a limited number of coupled cavities (six to ten, depending on the actual Q).