Topological supermodes in photonic crystal fiber

Abstract

Topological states enable robust transport within disorder-rich media through integer invariants inextricably tied to the transmission of light, sound, or electrons. However, the challenge remains to exploit topological protection in a length-scalable platform such as optical fiber. We demonstrate, through both modeling and experiment, optical fiber that hosts topological supermodes across multiple light-guiding cores. We directly measure the photonic winding number invariant characterizing the bulk and observe topological guidance of visible light over meter length scales. Furthermore, the mechanical flexibility of fiber allows us to reversibly reconfigure the topological state. As the fiber is bent, we find that the edge states first lose their localization and then become relocalized because of disorder. We envision fiber as a scalable platform to explore and exploit topological effects in photonic networks.

Model-free characterization of topological edge and corner states in mechanical networks

“… 32 . is a local material property that generalizes earlier macroscopic markers of topological phase models: the topological polarization introduced by Kane and Lubensky ( 8 ), the topological contribution to the polarization of electronic insulators ( 33 ), and the mean chiral displacement of photonic metamaterials ( 34 , 35 ). We explain how to measure and show that floppy and self-stress modes correspond to net mechanical charges signaled by topological defects in the chiral polarization field ( Fig.…”

Optical Fibers Go Topological

“…U sing concepts from the mathematical field of topology, researchers at the University of Bath, UK, have designed an optical fiber that can robustly propagate light, even if there are variations in the properties of its light-guiding materials or in its overall geometry [1]. The team thinks that this newfound topological protection could enable advances in optical communication and photonic quantum To make a topological fiber, a team of researchers from the University of Bath stretched a stack of glass tubes and solid-core rods into a thin fiber.…”

“…By tuning the size of the tubes, the team was able to control how light tunneled between channels created by the rods. Credit: N. Roberts et al [1] computing.…”