{ "id": "2303.18199", "version": "v1", "published": "2023-03-30T03:49:42.000Z", "updated": "2023-03-30T03:49:42.000Z", "title": "SU(2) Symmetry of Coherent Photons and Application to Poincaré Rotator", "authors": [ "Shinichi Saito" ], "categories": [ "physics.optics" ], "abstract": "Lie algebra is a hidden mathematical structure behind various quantum systems realised in nature. Here, we consider $SU(2)$ wavefunctions for polarisation states of coherent photons emitted from a laser source, and discuss the relationship to spin expectation values with SO(3) symmetry based on isomorphism theorems. In particular, we found rotated half-wave-plates correspond to mirror reflections in the Poincar\\'e sphere, which do not form a subgroup in the projected O(2) plane due to anti-hermitian property. This could be overcome experimentally by preparing another half-wave-plate to realise a pristine rotator in $SU(2)$, which allows arbitrary rotation angles determined by the physical rotation. By combining another 2 quarter-wave-plates, we could also construct a genuine phase-shifter, thus, realising passive control over the full Poincar\\'e sphere.", "revisions": [ { "version": "v1", "updated": "2023-03-30T03:49:42.000Z" } ], "analyses": { "keywords": [ "coherent photons", "application", "full poincare sphere", "arbitrary rotation angles", "spin expectation values" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }