The suitability of normal SOI nanowaveguides for terahertz pulse train generation

We numerically study the modulational instability (MI) gain at low input powers in a normal silicon-on-insulator (SOI) nanowaveguide. We find that, taking free carrier (FC)-effects in the MI gain analysis made the modulation unstable, due to an additional interaction of free carrier-induced dispersion and nonlinearity and hence made the normal SOI nanowaveguide suitable for nonlinear devices like terahertz pulse train generation, super continuum generation and wavelength conversion.