Electrically tunable photo-aligned hybrid double-frequency liquid crystal polarisation grating

ABSTRACTA polarisation grating (PG) based on the hybrid photo-aligned double-frequency liquid crystal has been demonstrated and fabricated in this paper. The single-order diffraction efficiency is above 95% for circular polarisation incident light. The PG can be driven by 2.5 V/µm electric field with alternating frequency and has no Freedericksz transition threshold. In response time, the rise time and decay time are 650 and 950 , respectively; the sub-millisecond can be achieved under a low driving voltage.