Vortex-Generating Light-Induced Phase Converter in Azobenzene Polymer

The formation of the modified area, which acts as phase converter for vortex generation, in the amorphous thin layer of the azo-containing polymer under the action of structured light beam is considered. The optical axes are produced in accordance with the polarization structure of the pump light beam. The beam with radial polarization induces the axially-symmetric optical axis distribution (similar to q-plate) with negative optical anisotropy proportional to the light beam intensity. We demonstrate that this light-induced modification can efficiently convert the probe Gaussian beam into optical vortex with the topological charge 2.