POLARIZATION CONVERTER IN A BURIED SI-WIRE WAVEGUIDE LOADED WITH A METAL STRIP

A polarization converter with a metal strip is developed in a buried waveguide with a rectangular core. The eigenmode analysis reveals that the insertion loss is mainly due to the field mismatch of the TM mode at the connection between the input (output) and conversion waveguides. It is found that the transition loss of the TM mode decreases，as the aspect ratio of the core is increased，leading to a reduction in the insertion loss