  A fast, switchable electro-optic radial polarization retarder (EO-RPR)
fabricated using the electro-optic ceramic PMN-PT is presented. This EO-RPR is
useful for fast, switchable generation of pure cylindrical vector beam. When
used together with a pair of half-wave plates, the EO-RPR can change circularly
polarized light into any cylindrical vector beam of interest such as radially
or azimuthally polarized light. Radially and azimuthally polarized light with
purities greater than 95% are generated experimentally. The advantages of using
EO-RPR include fast response times, low driving voltage and transparency in a
wide spectral range (500 -7000 nm).
