Dielectric surrounding bleaches the optical bond between a microdisk resonator and a straight optical waveguide
We performed a numerical study of a surrounding medium influence on coupling
efficiency between a microdisk resonator supporting optical whispering gallery modes and a
straight optical waveguide. Quality factors of the modes and relative optical power coupled to
the waveguide were calculated using COMSOL Multiphysics environment. It was shown that
the most efficient coupling takes place when propagation constants of the modes of the
microdisk and the waveguide match. The coupling can be significantly strengthened by
increasing the index of the surrounding medium.