Coupled-resonator optical waveguide: a proposal and analysis

We propose a new type of optical waveguide that consists of a sequence of c oupled high-Q resonators. Unlike other types of optical waveguide, waveguid ing in the coupled-resonator optical waveguide (CROW) is achieved through w eak coupling between otherwise localized high-Q optical cavities. Employing a formalism similar to the tight-binding method in solid-state physics, we obtain the relations for the dispersion and the group velocity of the phot onic band of the CROW's and find that they are solely characterized by coup ling factor kappa(1). We also demonstrate the possibility of highly efficie nt nonlinear optical frequency conversion and perfect transmission through bends in CROW's. (C) 1999 Optical Society of America.