Polarization mode conversion in an optical microdisk resonator vertically coupled to a waveguide bus

Due to the existence of non-zero, and asymmetric cross-polarization coupling coefficients between a microdisk and a waveguide, microdisks with minimal internal losses and small radii vertically coupled to waveguides can be engineered as a polarization rotator. A semi-analytical calculation method is presented to realize microdisk-waveguide system as a polarization rotator.