Arbitrary power-splitting-ratio achieved in 1x2 hybrid plasmonic multimode interference device by structure symmetry broken

Abstract

The power-splitting-ratio (PSR) of the 1 x 2 multimode interference (MMI) device based on hybrid plasmonic waveguide is studied theoretically. Other than the finite and fixed PSR in conventional MMI, by rational breaking the symmetry of the structure, arbitrary PSR can be achieved, while the original advantages of MMI devices including large fabrication tolerance, wide operation bandwidth, and compact size (1x1.1-1.5 mu m(2)) are well-kept. Besides, unlike the regular hybrid-plasmonic-waveguide based device suitable only to TM polarization, the power splitter design presented here could be also possible available to TE polarization incidence. Introducing tapered structure may further improve its performance on both TE and TM polarization cases.