Tuneable modulating metasurface at visible and near-IR wavelengths

Abstract

Integrated photonic modulators have recently attracted interest for optical neural network (ONN) applications. Networks of this kind offer an interesting approach to overcoming the expected digital computational efficiency saturation of the classical von Neumann architecture. Most ONN geometries only employ a 1D waveguide approach, which suffers from a limited number of I/O channels. Using a 2D architecture operating at near-IR wavelengths offers the ability to process a much larger data volume. Here, we present an out-of-plane reconfigurable plasmonic modulator, capable of tuning the phase of incident light using a simple architecture with no moving parts. The device consists of a compact layered structure, using an indium tin oxide (ITO) active material to electronically control the permittivity, generating signal manipulation as a function of voltage. Through numerical simulations, we achieve a π phase shift with an input voltage of 14 V at an operating wavelength of 780 nm. This work provides a robust solution to electro-optic phase modulation at visible and near-IR wavelengths, enabling applications in several important areas such as optical computing and virtual reality.