Ultrabroadband gradient-pitch Bragg-Berry mirrors

摘要: The realization of a geometric phase optical device operating over broad spectral range is usually confronted with intrinsic limitations depending on the physical process at play. Here we propose to use chiral nematic liquid-crystal slabs helical ordering that varies in three dimensions, namely, gradient-pitch cholesterics endowed in-plane space-variant angular positioning supramolecular helix. By doing so, show recently introduced Bragg-Berry mirrors [M. Rafayelyan and E. Brasselet, Opt. Lett. 41, 3972 (2016).] can be an ultrabroadband range. Experimental demonstration made case vortex generation visible domain. These results offer practical solution polychromatic management orbital momentum light combining circular Bragg reflection media Berry phase.