Compact Plasmonic Logic Gates Enabled by Magnetoelectric Light Funneling for On-Chip Optical Computing in the Telecom Band

Abstract

The realization of all-optical logic gates (AOLGs) is important for advancing photonic integrated circuit (PIC) design and optical data communication. Various photonic structures and design techniques, including two-dimensional photonic crystals, silicon waveguides, plasmonic waveguides, diffractive neural networks, and inverse design techniques, are actively being explored to achieve multifunctional, high-performance optical logic gates with fast data processing capabilities. Among these, plasmonic structure-based AOLGs often face challenges such as fabrication complexity and large device footprints when integrating multiple logic operations within a single structure. In this work, a planar and compact metal-insulator-metal (MIM) plasmonic waveguide structure is proposed for AOLG design, utilizing the light funneling effect in grooved metasurfaces. The designed device, with dimensions of 700 nm X 460 nm, successfully implements three fundamental logic gates (NOT, AND, OR) with a high contrast ratio of 18.69 dB. The device operates within the wavelength range of 1400 nm to 1450 nm, making it suitable for the telecommunications field. Its planar architecture offers fabrication feasibility and all logic gates can be controlled using a single light source incident from one specific direction, which facilitates its integration into photonic circuits with fast operational speed. This work contributes to the advancement of scalable and high-speed photonic computing platforms.