Broadband spectra translation between mid-infrared band and telecom band in a nonlinear silicon-based symmetric hybrid plasmonic waveguide

A symmetric hybrid plasmonic waveguide is designed to realize high-efficient conversion between mid-infrared (MIR) and telecom wavelength bands. The proposed hybrid plasmonic waveguide consists of an insulator-metal-insulator structure buried into a silicon ridge on silica substrate. By using geometry optimization, the dispersion of waveguide is optimized, leading to broadband (resulting in a 3-dB bandwidth of 1,919 nm from 1.496 mu m to 3.415 mu m) and efficient (resulting in a peak conversion efficiency of -18.9 dB) four-wave mixing (FWM) in a 200-mu m-long waveguide pumped by a 1.725-mu m source of 0.5 W. This waveguide configuration shows its great potential in all-optical switching between MIR band and telecom band.