2 × 2 Compact Silicon Waveguide-Based Optical Logic Functions at 1.55 μm

Compact waveguide crossing is a fundamental component of optoelectronic fusion chip solutions due to its orders-of-magnitude smaller footprint than that of conventional photonic integrated circuits. In this paper, we suggest 2 × 2 compact silicon-on-silica waveguides that can implement all of the fundamental Boolean logic functions, including XOR, AND, OR, NOT, NOR, XNOR, and NAND, operated at 1.55 μm. Three input waveguides, one output waveguide, and a design area compose the proposed waveguide. The execution of the specified logic gates relies on the constructive and destructive interferences produced by the phase variations between the input beams. The contrast ratio (CR) is employed as a performance metric to assess how well these logic functions operate. In comparison to other reported designs, the proposed waveguide achieves higher CRs at a high speed of 120 Gb/s.