4:00 PM - 4:15 PM
▲ [7p-A409-9] Tunable reflective liquid crystal terahertz waveplates
Keywords:terahertz, liquid crystal, waveplate
Tunable liquid crystal devices that can change terahertz wave polarization continuously have many potential applications in THz optical systems. We present a reflective liquid crystal THz waveplate with sub-wavelength metal grating and metal ground plane electrodes. The thickness of the liquid crystal layer can be reduced to ~10% of that needed for the same phase shift at a given frequency in a transmissive waveplate. We experimentally demonstrate the same tunability as in the transmissive type just using half the thickness. We discuss the dependence on the angle of incidence for phase shift tunability, which can achieve beam steering and polarization conversion at the same time.