Topological one-way large-area waveguide states in magnetic photonic crystals

TL;DR

This paper demonstrates large-area, one-way waveguide states in magnetic photonic crystals that enable robust, unidirectional energy transport and beam narrowing, resistant to defects and disorder.

Contribution

The study introduces a novel heterostructure design achieving large-area, one-way waveguide states with experimental validation, enhancing robustness and control in photonic transport.

Findings

Successful experimental realization of large-area one-way waveguide states.

Waveguide states support unidirectional transport despite non-magnetized medium.

Robustness of waveguide modes against defects and disorder.

Abstract

We have theoretically and experimentally achieved large-area one-way transport by using heterostructures consisting of a domain of an ordinary photonic crystal (PC) sandwiched between two domains of magnetic PCs. The non-magnetized domain carries two orthogonal one-way waveguide states which have amplitude uniformly distributed over a large-area. These two waveguide states support unidirectional transport even though the medium of propagation is not magnetized. We show both experimentally and numerically that such one-way waveguide states can be utilized to abruptly narrow the beam width of an extended state to concentrate energy. Such extended waveguide modes are robust to different kinds of defects, such as voids and PEC barriers. They are also immune to the Anderson type localization when large randomness is introduced.