Dielectric Metasurfaces Enabled Ultradensely Integrated Multidimensional Optical System

Metasurfaces consisted of subwavelength nanostructures can extremely interact with light and manipulate the characteristics of amplitude, phase, and polarization. In particular, on-chip dielectric metasurfaces have attracted significant attention for optical communication and computing, due to its compact footprint, low loss, and broad bandwidth. Herein, an ultradensely integrated multidimensional optical system with a footprint of only 20 × 30 µm² based on inverse-designed dielectric metasurface network, incorporating mode-division multiplexing, and coherent optical communication technologies that can multiply the system capacity is demonstrated. It is assembled by the ultracompact multifunction on-chip metasurface devices, including four-mode demultiplexer, optical hybrid, crossing, and bending, which all have a size of only several micrometers. The inverse-designed work can significantly broaden the integrated device applications of on-chip metasurfaces and pave an alternative way for large-scale high-capacity optical communication system.