Topological photonic crystal fibre

Abstract

Photonic crystal fibres (PCFs) are optical fibres that guide light using a modulated dielectric medium. They provide an exceptionally versatile platform for various applications, thanks to the flexibility with which light-guiding can be customised by modifying the fibre geometry. Here, we realise a PCF with guided modes produced by photonic bandstructure topology rather than conventional mode-trapping mechanisms. The design, which is compatible with the stack-and-draw fabrication process, consists of a cross-sectional photonic topological crystalline insulator with a disclination. A bulk-defect correspondence produces degenerate topological modes, lying below the cladding light line. We use various theoretical methods to confirm their topological origins, including a spectral localiser that makes minimal assumptions about the bandstructure. Our experiments on the fabricated topological fibre show it transmitting visible to near-infrared light with low losses of 10--20 dB/km, which do not increase much when the fibre is bent. A comparable solid-core PCF of conventional design exhibits substantially higher bending losses. Optical fibres based on topological modes thus hold promise for improved performance and novel functionalities.

References in corpus (31)

• Topological Photonics
• Scheme to Achieve Silicon Topological Photonics
• Quantization of fractional corner charge in $C_n$-symmetric higher-order topological crystalline insulators
• All-Si Valley-Hall Photonic Topological Insulator
• Topological photonic crystals: physics, designs and applications
• Hybrid photonic-crystal fiber
• Experimental discovery of bulk-disclination correspondence
• Two-Dimensionally Confined Topological Edge States in Photonic Crystals
• Band topology in classical waves: Wilson-loop approach to topological numbers and fragile topology
• Dirac-vortex topological cavity
• Fractional disclination charge in two-dimensional $C_n-$symmetric topological crystalline insulators
• Recent advances in supercontinuum generation in specialty optical fibers [Invited]
• K-Theory and Pseudospectra for Topological Insulators
• Tutorial: Computing topological invariants in two-dimensional photonic crystals
• Observation of Protected Photonic Edge States Induced By Real-Space Topological Lattice Defects
• Braiding photonic topological zero modes
• Vortex states in an acoustic Weyl crystal with a topological lattice defect
• Dirac-vortex topological photonic crystal fibre
• Topological Phases of Photonic Crystals under Crystalline Symmetries
• Photonic Band Gap Effects in Two-dimensional Polycrystalline and Amorphous Structures
• Topologically protected vortex transport via chiral-symmetric disclination
• Topological supermodes in photonic crystal fiber
• Topological photonic crystal fibers and ring resonators
• An operator-based approach to topological photonics
• Topological photonic crystal fibers based on second-order corner modes
• Local markers for crystalline topology
• Quadratic pseudospectrum for identifying localized states
• Hybrid topological guiding mechanisms for photonic crystal fibers
• Spectral localizer for line-gapped non-hermitian systems
• Tutorial: Classifying Photonic Topology Using the Spectral Localizer and Numerical $K$-Theory
• Lecture Notes on Topological Crystalline Insulators