Design of plasmonic half-adder and half-subtractor circuits employing nonlinear effect in Mach-Zehnder interferometer

Plasmonic metal-insulator-metal (MIM) waveguides have the unique attribute of propagating surface plasmons beyond the diffraction limit. In this paper, basic designs for half-adder and half-subtractor circuits are proposed based on the nonlinear effect in Mach-Zehnder interferometers designed using plasmonic MIM waveguides. The proposed devices are studied in the third optical communications window with transverse magnetic polarization. The designs are verified by the finite-difference time-domain technique with the help of MATLAB simulations.