Perfect Higher-Order Poincaré Sphere Beams from Digitalized Geometric Phases

The higher-order Poincare (HOP) sphere beam generalizes optical vortices and vector beams, vividly illustrating their higher-order polarization states. However, its doughnutlike intensity profile varies significantly with topological charge, restricting its application in optics. The authors study a perfect HOP sphere, whose annular intensity profile is $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}d\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}p\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}d\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}t$ of topological charge. Single- and multiringed beams are produced in anisotropic medium, by exploiting a spiral geometric phase and aptly designed gratings. This work provides an exciting technique for manipulating the angular momentum of light, to improve $e.g.$ optical tweezers, or multiplexing in optical communication.