Experimental demonstration of valley-Hall topological photonic crystal at telecommunication wavelengths

TL;DR

This paper reports the first experimental demonstration of a valley-Hall topological photonic crystal operating at telecommunication wavelengths, showcasing topologically protected edge states in a CMOS-compatible chip.

Contribution

It presents the design, fabrication, and experimental validation of a topological photonic structure at telecommunication wavelengths, advancing integrated topological photonics.

Findings

Demonstrated topologically protected edge states at telecom wavelengths

Validated CMOS-compatible fabrication of topological photonic structures

Showed potential for lossless optical communication systems

Abstract

Photonic topological insulators provide unprecedented possibilities to eliminate scattering losses and improve the efficiency of optical communication systems. Despite significant theoretical efforts, the experimental demonstration of an integrated photonic topological insulator operating in the telecommunication regime was still missing. Here, we design, fabricate and characterize a photonic-crystal-based topological structure that exhibits valley-Hall effect. We experimentally demonstrate the propagation of topologically protected edge states in a CMOS-compatible chip operating at telecommunication wavelengths. This contribution is an important step towards integrated topological photonics.