Liquid-crystal splitter for generating and separating autofocusing and autodefocusing circular Airy beams.

A unique splitter is proposed and demonstrated to realize the generation and separation of autofocusing and autodefocusing circular Airy beams (CABs). The design of the splitter is derived from the Fourier transform of a CAB associated with the Pancharatnam-Berry phase, and the fabrication is carried out via a liquid-crystal photo-patterning technique. Autofocusing and autodefocusing CABs of orthogonal circular polarization states are spatially diffracted under the modulation of the splitter, and the energy distribution between these two CABs can be controlled by the incident polarization. A focal length of 40 cm is obtained, which can be customized as required. The propagation dynamics of the generated autofocusing and autodefocusing CABs are investigated, and the experimental results are in good accordance with the corresponding simulations. The additional merits of the splitter, such as reconfigurability, tunability, high efficiency, and wide operating wavelength range, may motivate novel applications of CABs in the areas of laser optics, biomedicine, and modern displays.