Finite-size effect on one-dimensional coupled-resonator optical waveguides

The finite-size effect on the dispersion relation and the group velocity of one dimensional coupled-resonator optical waveguide (CROW) structures, was studied. Thelen's method was used to optimize the configuration of the CROW structure and to reduce the oscillations on the transmission and group velocity curves. The results show that the dispersion relation and the group velocity curves of a finite-size CROW oscillate along those of the corresponding infinite-extended ones. The results also show that the bandwidth and the group velocity in the impurity pass band depend on the structure configuration of the unit cell, but not on the number of the unit cell.