Mimicking optical activity for generating radially polarized light

We propose a new scheme for generating radially polarized light by mimicking optical activity using linear birefringence. It involves a birefringent spirally varying retarder sandwiched between two orthogonally oriented quarter-wave plates. Using Poincaré sphere representation, we show that the polarization transformation of such a scheme is equivalent to that of a spirally varying optical activity and is capable of generating radially polarized light. We demonstrate the proof-of-concept using y-cut crystalline quartz.