Silicon-on-silica waveguides-based all-optical logic gates at 1.55 μm

The demand for faster and more efficient integrated photonic circuits has prompted the rise of silicon-on-insulator technology. In this paper, silicon-on-silica waveguides have been employed for the all-optical realization of a complete family of logic gates, including XOR, AND, OR, NOT, NOR, NAND and XNOR operated at 1.55 mu m. This waveguide consists of three identical slots and six microring resonators, all made of silicon patterned on silica. The principle of operation of these logic gates is based on the constructive and destructive interference induced by the phase difference between the input signals. The gates' performance is evaluated against the contrast ratio (CR) metric. Compared to existing waveguides, the proposed waveguides achieve higher CRs with a speed as high as 120 Gb s(-1).