Abstract
We have constructed and characterized THz phase shifters based on liquid crystals (LCs) with graphene grown by chemical vapor deposition (CVD) and indium-tin-oxide nanowhiskers (ITO NWhs) as transparent conducting electrodes. A graphene-based phase shifter can achieve a phase shift of π/2 at 1.0 THz with the operating voltage of ∼2.2 V (rms) as opposed to ∼ 5.6 V (rms) for ITO-NWhs-based phase shifter in previous work. On the other hand, 2π phase shift at 1.0 THz was achieved in an ITO-NWhs-based phase shifter with a multi-sandwiched structure by applying ∼2.6 V (rms). The low operation voltage of both two kinds of phase shifters imply compatibility of both type of devices with thin-film transistor (TFT) and complementary metal-oxide-semiconductor (CMOS) technologies. The experimental results of phase shifters are in good agreement with the theoretical predictions. © SPIE. Downloading of the abstract is permitted for personal use only 2015.