Multichannel and Binary-Phase All-Optical Control with On-Chip Integrated Subwavelength Plasmonic Waveguides

Abstract

The control of light with light at a nanometer scale is a fundamental issue in optics. In this study, we demonstrate nanoscale all-optical control of light based on linear optics in an on-chip integrated subwavelength plasmonic waveguide system. The signal intensities of multiple output channels are all-optically manipulated simultaneously in various manners by coupling the fields of a standing wave in the main waveguide to the nearby subwavelength branch waveguides. More importantly, the phase differences between different output channels equal either 0 or π, thereby exhibiting an interesting binary characteristic. This phenomenon provides both phase robustness and switchable features, which significantly facilitate further applications at nanometer scales. As a demonstration, two output channels are used to drive a two-element plasmonic nanoantenna, and the dynamical control of the emission direction of the nanoantenna is successfully presented. The proposed control mechanism displays an ultrafast respo...