Taming the swirl of self-structured liquid crystal q-plates

International audience; Spontaneously formed liquid crystal topological defects under external fields offer a nature-assisted route to the creation of geometric phase optical vortex generators (q-plates). Here we report on the consequences of the unavoidable swirled transverse spatial distribution of the optical axis of such optical elements on the beam shaping and we propose a swirl-compensation scheme based on the arithmetic of geometric phase optical elements.