Four-terminal silicon waveguides for optical logic functions at 1.55 μm

Silicon-on-insulator-based integrated optical circuits are anticipated to become dominant in the photonics industry. This paper showcases a significant advancement by demonstrating the realization of seven optical logic functions using four-terminal silicon-on-silica waveguides operating at 1.55 μm. The simulations were carried out with Lumerical FDTD software, showcasing successful execution through precise adjustment of incident beam phases. The evaluation of our approach’s efficacy relies on the contrast ratio (CR), a key metric for assessing the performance of the targeted logic functions. Additionally, we scrutinize the influence of crucial operating parameters on the waveguide’s performance. Notably, our waveguides outperform previous works, achieving substantially higher CRs of 33.5 dB, 25 dB, 30 dB, 25 dB, 24.7 dB, 26 dB, and 27.34 dB for logic XOR, AND, OR, NOT, NOR, NAND, and XNOR, respectively. What sets our findings apart is the accomplishment of these results at an elevated data speed of 120 Gb/s, showcasing the potential for high-speed data processing applications.