Optical quasi logic gates based on polarization-dependent four-wave mixing in subwavelength metallic waveguides

All-optical quasi logic gates are demonstrated by means of polarization-dependent four-wave mixing (FWM) in metal-insulator-metal (MIM) waveguides filled with a Kerr nonlinear medium. By using finite-difference-time-domain (FDTD) methods, we perform a quantitative comparison of the FWM efficiency associated with different pump polarization states. By manipulating the core thickness and the polarization properties of the pump and signals, all-optical NOT, NAND, NOR, and NXOR logical functions are obtained.