Design of a three-input all-optical compact NOR gate based on a two-dimensional photonic crystal

In this article, a NOR gate with three optical inputs is designed in the substrate of two-dimensional photonic crystals. A combination of multiple gates is used to design electronic gates with more inputs. A single structure can be used directly for multi-input gates in photonic crystals. In this article, a three-input optical NOR gate is designed using photonic crystals with a small size and a simple structure. The high and low logic at the input and output is defined based on the optical power of the input source in the "ON" state. For light propagation in the structure, the property of PBG is used, which is that light is guided through waveguides. In the design of this gate, the difference between the upper and lower logic states has been tried to be maximized. The features of the proposed gate are the simplicity of the structure and the use of low-defect rods and simple waveguides. These features make the proposed NOR gate suitable for compact, high-precision optical integrated circuits.