Discontinuous spectral element method modeling of optical coupling by whispering gallery modes between microcylinders

We introduce a high-order time-domain discontinuous spectral element method for the study of the optical coupling by evanescent whispering gallery modes between two microcylinders, the building blocks of coupled resonator optical waveguide devices. By using the discontinuous spectral element method with a Dubiner orthogonal polynomial basis on triangles and a Legendre nodal orthogonal basis on quadrilaterals, we conduct a systematic study of the optical coupling by whispering gallery modes between two microcylinders and demonstrate the successful coupling between the microcylinders and also the dependence of such a coupling on the separation and the size variation of the microcylinders.