Topological-darkness-assisted phase regulation for atomically thin meta-optics

TL;DR

This paper demonstrates that structured PtSe2 films can achieve atomic-thick meta-optics with high diffraction efficiency by leveraging topological darkness, enabling light manipulation at an atomic scale despite the challenges of 2D materials.

Contribution

It introduces a novel approach using topological darkness in 2D PtSe2 films to realize atomic-thick meta-optics with high efficiency, overcoming previous limitations.

Findings

Achieved 0.96%/nm diffraction efficiency at atomic thickness.

Demonstrated angle-robust meta-optics with 4.3 nm thick PtSe2.

Showed light manipulation at atomic scale using topological darkness.

Abstract

Two-dimensional (2D) noble-metal dichalcogenides have emerged as a new platform for the realization of versatile flat optics with a considerable degree of miniaturization. However, light field manipulation at the atomic scale is widely considered unattainable since the vanishing thickness and intrinsic losses of 2D materials completely suppress both resonances and phase accumulation effects. Empowered by conventionally perceived adverse effects of intrinsic losses, we show that the structured PtSe2 films integrated with a uniform substrate can regulate nontrivial singular phase and realize atomic-thick meta-optics in the presence of topological darkness. We experimentally demonstrate a series of atomic-thick binary meta-optics that allows angle-robust and high unit-thickness diffraction efficiency of 0.96%/nm in visible frequencies, given its thickness of merely 4.3 nm. Our results unlock the potential of a new class of 2D flat optics for light field manipulation at an atomic thickness.