Ultra-Compact All-Optical NAND Logic Gates Based on 4 × 4 MMI Coupler Using Silicon Hybrid Plasmonic Waveguides

Abstract

AbstractWe present a new structure based on ultra-compact cascaded multimode interference (CS-MMI) structures using silicon hybrid plasmonic waveguides (HPWG) for an all-optical NAND logic gate. An ultra-compact footprint of 3 × 16 µm2 can be achieved. We show that the contrast ratios for logic 1 and logic 0 for NAND gates are about 25 dB for a ultra-high bandwidth of 70 nm, respectively. A large fabrication tolerance can be achieved by using this structure. This all-optical NAND gate can be useful for all-optical high speed networks.