All-Si Valley-Hall Photonic Topological Insulator

TL;DR

This paper proposes an all-silicon photonic structure that emulates quantum-valley-Hall effects, functioning as a topological insulator with scattering-free edge states, enabling efficient light coupling and robust photonic devices.

Contribution

It introduces a novel all-Si photonic topological insulator based on valley-Hall effects, demonstrating topologically protected edge states for integrated photonics.

Findings

Supports scattering-free edge states

Enables efficient light coupling between free space and photonic structure

Facilitates design of reflection-free resonant photonic cavities

Abstract

An all-Si photonic structure emulating the quantum-valley-Hall effect is proposed. We show that it acts as a photonic topological insulator (PTI), and that an interface between two such PTIs can support edge states that are free from scattering. The conservation of the valley degree of freedom enables efficient in- and out-coupling of light between the free space and the photonic structure. The topological protection of the edge waves can be utilized for designing arrays of resonant time- delay photonic cavities that do not suffer from reflections and cross-talk.