Concurrent implementation of all-optical half-adder and AND & XOR logic gates based on nonlinear photonic crystal

A new design for concurrent implementation of all-optical half-adder and AND & XOR logic gates based on nonlinear photonic crystal ring resonator has been proposed. The finite different time domain and plane wave expansion methods are used to analyze the behavior of the structure. The ring resonator has a low switching time of about 0.85 ps and low switching power equal to $277,text{ mW}/upmu text{m}^{2}$ 277 mW / μ m 2 . The simulation results show that the contrast ratio is 12.78 dB for AND gate and 5.67 dB for XOR gate. Moreover, the operational wavelength of the input ports is $1.55,upmu text{m}$ 1 . 55 μ m . Since the structure has a simple geometric shape with clear operating principle, it is potentially applicable for photonic integrated circuits.