Low loss coupler to interface silicon waveguide and hybrid plasmonic waveguide

A metallic coupler is proposed to interface a silicon on insulator (SOI) waveguide with a narrow hybrid plasmonic waveguide (200× 200 nm). The device operation is investigated and optimized to attain the best tradeoff between the mode confinement and the propagation loss. Calculations reveal that a high confinement and low loss of the energy is achieved from a silicon slab waveguide into the dielectric slot of area 200×200 nm2 and a coupling efficiency of 70% (0.8 dB) at the 1.55 μm telecommunication wavelength can be achieved.