Optically recorded polymer-based optical vortex generator

Polarization converters for the generation of structured light beams, in particular, optical vortices, are widely used in various fields of science and applications. The search for affordable and adaptable (reconfigurable) systems that allow efficient conversion remains relevant. This paper discusses the formation of a polarization converter through optical modification of a thin layer of an amorphous azobenzene-containing polymer by exposure to a laser beam. Such a material exhibits optical anisotropy due to the redistribution of absorbing fragments caused by light-induced trans-cis transitions. It is shown that under the action of a light beam with an axially symmetric polarization distribution, a corresponding distribution of the induced optical axis is created with a high degree of locality. The induced anisotropy persists up to the melting point and can be rewritten by subsequent exposure to light.