Transparent subdiffraction optics: nanoscale light confinement without metal

TL;DR

This paper introduces a novel method for confining light below the diffraction limit using transparent artificial media, avoiding metals and reducing cross talk in nanophotonic devices.

Contribution

It presents a new paradigm for light confinement by controlling evanescent wave momentum with transparent materials, surpassing metal-based and dielectric approaches.

Findings

Achieves subdiffraction light confinement without metals.

Reduces cross talk by an order of magnitude.

Proposes waveguides outperforming existing photonic structures.

Abstract

The integration of nanoscale electronics with conventional optical devices is restricted by the diffraction limit of light. Metals can confine light at the subwavelength scales needed, but they are lossy, while dielectric materials do not confine evanescent waves outside a waveguide or resonator, leading to cross talk between components. We introduce a paradigm shift in light confinement strategy and show that light can be confined below the diffraction limit using completely transparent artificial media. Our approach relies on controlling the optical momentum of evanescent waves, an important electromagnetic property overlooked in photonic devices. For practical applications, we propose a class of waveguides using this approach that outperforms the cross talk performance by 1 order of magnitude as compared to any existing photonic structure. Our work overcomes a critical stumbling block for nanophotonics by completely averting the use of metals and can impact electromagnetic devices from the visible to microwave frequency ranges.