Theoretical investigation of silicon MOS-type plasmonic slot waveguide based electrooptic modulators

A silicon nanoplasmonic electrooptic modulator is designed and theoretically analyzed, which is composed of lateral silicon metal-SiO₂-Si-metal plasmonic hybrid slot waveguides for phase shifter and ultracompact V-shape splitter/combiner to link the plasmonic waveguides and the Si dielectric waveguides, thus it can be directly implemented into the conventional Si dielectric waveguide based electronic photonic integrated circuits and be fabricated using fully CMOS compatible processes. The modulator parameters are optimized through a systematic analysis using 2D numerical simulation. For a modulator with 3-μm-long Cu-SiO₂(2nm)-Si(50 nm)-Cu phase shifter and 0.35-μm-long splitter/combiner operating at 1.55-μm wavelength, numerical simulation shows insertion loss of ~ -8.7 dB, extinction ratio of -6.8 dB - which is achieved at -5.6 V bias, and speed of ~500 GHz.