Topological Polarisation States

Abstract

Polarisation states are described by spin expectation values, known as Stokes parameters, whose trajectories in a rotationally symmetric system form a sphere named after Poincaré. Here, we show that the trajectories of broken rotational symmetric systems can exhibit distinct topological structures in polarisation states. We use a phase-shifter to form a polarisation circle (${\mathbb{S}}^1$), which interferes with the original input due to the phase change of the output state upon the rotation. By rotating the circle using a rotator, the trajectories become a polarisation torus (${\mathbb{S}}^1\times {\mathbb{S}}^1$), which was experimentally confirmed in a simple set-up using passive optical components together with Mach-Zehnder interferometers. We also discuss about realisations of other topological features, such as Möbius strip, Hopf-links, and topological Dirac bosons with a bulk-edge correspondence.

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Cited by in corpus (5)

• Photonic Quantum Chromo-Dynamics
• Spin of Photons: Nature of Polarisation
• Macroscopic Single-Qubit Operation for Coherent Photons
• Dirac Equation for Photons: Origin of Polarisation
• Macroscopic Singlet, Triplet, and Colour-Charged States of Coherent Photons