Fast optical retarder using deformed-helical ferroelectric liquid crystals

We develop half-wave retarder based of deformed-helical ferroelectric (DHF) liquid crystal cell. Birefringence and thickness of DHF cell is optimized to obtain ninety degrees rotation of the light polarization. An optical scheme of crossed-switch between two inputs and two outputs channels using such DHF cell is discussed. The switching time, less than 10 microseconds at controlling voltage of 20V can be provided, which is temperature independent over the broad temperature range