Ultra-large nonlinear parameters and all-optical modulation of a transition metal dichalcogenides on silicon waveguide.

We integrate monolayer TMDCs into silicon-on-insulation (SOI) waveguides and dielectric-loaded surface plasmon polariton (DLSPP) waveguides to enhance nonlinear parameters (γ) of silicon-based waveguides. By optimizing the waveguide geometry, we have achieved significantly improved γ. In MoSe-on-SOI and MoSe-in-DLSPP waveguide with optimized geometry, the maximum γ at the excitonic resonant peak (λ) is 5001.87 Wm and 119111.94 Wm respectively for each case. Based on this, we designed all-optical TMDCs-on-SOI phase and extinction waveguide modulators, achieving π-phase and 3 dB modulation with millimeter-scale modulation lengths under an optical pump intensity of 1 GW/[Formula: see text] at the optical communication wavelengths of 1310 nm and 1550 nm. At the λ of MoSe, a modulation length of only 75 [Formula: see text]m is required for π-phase modulation, while a modulation length of 1.36 mm is sufficient for 3 dB modulation. Our work provides new insights for achieving miniaturized and low-power optical communication and networking applications.