Light control in a hemicylindrical whispering gallery microcavity-parallel plate waveguide system

We have shown that a structure composed of a semiconductor hemicylinder and a dielectric waveguide separated by a thin metal layer permits efficient and easy light control. In such a system, it is possible to ensure matching between TE and TM modes of a low refractive index waveguide with the corresponding whispering gallery modes of the hemicylinder of a higher refractive index, a circumstance that allows one to reduce the resonator sizes to the order of the exciting wavelength in the vacuum still having rather high Q-factor around 2*10^4. Due to pronounced electro-optical properties of the resonator medium, one is able to effectively control the output light intensity by varying the refractive index of the hemicylinder in the order of 10^(-4).