Topological light guiding and trapping via shifted photonic crystal interfaces

TL;DR

This paper introduces a novel method for guiding and trapping light using shifted photonic crystal interfaces, leveraging Dirac mass properties for efficient, disorder-robust photonic devices.

Contribution

It demonstrates the use of glide-symmetric photonic crystal interfaces with zero Dirac mass for high-performance, disorder-tolerant waveguides and explores bound states from opposite Dirac masses.

Findings

Zero Dirac mass GPCIs exhibit excellent transmission even with sharp corners.

Opposite Dirac mass GPCIs form photonic bound states.

GPCIs enable ultracompact photonic device design.

Abstract

Photonic crystals (PCs) are periodic dielectric structures that severed as an excellent platform to manipulate light. A conventional way to guide/trap light via PCs is to introduce a line or point defect by removing or modifying several unit cells. Here we show that the light can be effectively guided and trapped in the glided photonic crystal interfaces (GPCIs). The projected band gap of GPCIs, which depends on the glide parameter, is characterized by a Dirac mass. Interestingly, the GPCIs with zero Dirac mass is a glide-symmetric waveguide featured with excellent transmission performance even in the presence of sharp corners and disorders. Moreover, placing two GPCIs with opposite Dirac mass together results in a photonic bound state due to the Jackiw-Rebbi theory. Our work provides an alternative way towards the design of ultracompact photonic devices such as GPCIs-induced coupled cavity-waveguide system and waveguide splitter.