All-optical logic gate based on nonlinear effects of two-dimensional photonic crystals

: All-optical XOR, NOT and two-input AND logic gates are designed based on the nonlinear effect and linear interference effect of photonic crystals. The complex logic expressions are divided by inversion theorem, and all-optical NOR gate and four-input AND gate logic devices are designed by cascade combination. In this paper, the Finite-Difference Time-Domain (FDTD) method is used for simulation, and the coupling characteristics of nonlinear annular cavities are analyzed. Then, the above logic devices are designed under the condition that the signal wavelength is 1.47 mu m, and more input devices can be designed by expanding the input. The influence of signal power on the logic function of the four-input AND logic devices is analyzed. The results show that when the power of the signal light source is between 1.1 W/mu m 2 and 3.4 W/mu m 2 , the logical contrast ratio of the output is greater than 10 dB. The response time of the designed device is only 1.6 ps, the occupied area is small, and the device is easy to expand and integrate. It has great application prospect in optical processing systems and integrated optical paths.