Ultrafast All-Optical Reversible Peres and Feynman-Double Logic Gates with Silicon Microring Resonators

We present designs of reversible Peres logic gate and FeynmanDouble logic gate based on all-optical switching by two-photon absorption induced free-carrier injection in silicon add-drop microring resonators. The logic gates have been theoretically analyzed using time-domain coupled-mode theory and all-optical switching has been optimized for low-power (25 mW) ultrafast (25 ps) operation with high modulation depth (85 %) to enable logic operations at 40 Gb/s. The advantages of high Q-factor, tunability, compactness, cascadibility, reversibility and reconfigurability make the designs favorable for practical applications.