Broadband coupler between silicon waveguide and hybrid plasmonic waveguide.

Efficient broadband coupling of light between a dielectric waveguide and a hybrid plasmonic waveguide is investigated theoretically. A plasmonic linear taper is used as a coupler which connects the two types of waveguides. Broadband coupling is realized by such a compact plasmonic taper with a length of only 0.4 microm, which achieves a coupling efficiency of 70% (1.5 dB) at the 1.55 microm telecommunication wavelength.