Design and numerical analysis of multifunctional photonic crystal logic gates

All-optical multifunctional structures are at the beginning of the growth and development path to achieve an alloptical integrated circuit (AOIC). The main challenge of designing multifunctional all-optical nanostructures is to maintain the overall function of the structure compared to single-function nanostructures. Simultaneous application of logic gates of AND, XOR, half-adder, 1-bit comparator, reversible Feynman logic gate along with desirable and suitable function are some of the proposed nanostructure properties. The propagation modes in the structure are extracted by the plane wave expansion (PWE) method. The overall operation of the nanostructure, simulation, and numerical analysis of the proposed nanostructure for the submitted applications are performed using the numerical method finite-difference time-domain (FDTD). In the proposed multifunctional nanostructure, ultra-fast and ultra-compact logic gates with a maximum time delay of approximately 280 fs, an area of 104 mu m2, and a bit rate of 3.57 Tb/s are provided. In addition to the proposed ultra-compact logic gate, another advantage of the proposed multifunctional nanostructure is achieving the appropriate contrast ratio.