Designing a Circuit for High-Speed Optical Logic Half Subtractor

In this paper, a high-speed optical subtractor has been designed and simulated. This circuit is based on a photonic crystal structure with silicon rods embracing a circular cross-section in the air platform. This structure was performed based on the photonic band gap. The best performance of this subtractor is in the highly-usable telecommunication wavelength of 1550, laying in the range of the photonic band gap of this structure. To design the circuit, two inputs with optical sources and two outputs have been used for difference and borrow bit. The features of this logic half subtractor encompassed simple structure, small dimensions, and appropriate level of the outputs 1 and 0.