Dielectric optical waveguide coupling analysis using two-dimensional finite-difference in time-domain simulations

Wave Coupling in the coupling section of a dielectric optical waveguide is discussed using even- and odd-mode analysis. The dispersion relations of di fferent modes were obtained by solving Maxwell equations. The two-dimension al finite-difference in time-domain method was implemented to solve these e quations. The even and odd modes were characterized by applying different e xcitation sources. A large number of rime steps were taken to reveal the fi ne structure of the propagation modes. The propagation constants of these m odes at the coupling frequency were calculated, and the optical-coupling le ngth was dertermined. The,result is in good agreement with those obtained b y the Marcatili method. * (C) 2000 John Wiley St Sons, Inc.