Single-exposure fabrication of tunable Pancharatnam-Berry devices using a dye-doped liquid crystal.

We report a non-interferometric single-exposure technique for fabricating Pancharatnam-Berry (PB) devices with arbitrary wavefronts, via photo-patterning an azo-dye doped LC with a two-dimensional linear polarization field, whose local polarization direction can be controlled by a spatial light modulator (SLM) on the pixel level. Upon one exposure, different local LC orientations are generated simultaneously. The non-interferometric approach is insensitive to environmental disturbance, and moreover, the dynamic phase mask on the SLM can be conveniently reconfigured by a computer. Our fabricated PB gratings, q-plates and hologram exhibit good optical performances. Such a simple yet reconfigurable fabrication method enables new PB devices to be developed, and it would open a new gateway towards widespread applications.