Photonic crystals for on-off switching of sub-terahertz electromagnetic waves

We present a sub-terahertz wave on-off switch based on a two-dimensional photonic crystal (PC). The PC consists of a triangular hole array in high density polyethylene (HDPE). The holes are infiltrated with the nematic liquid crystal 5CB. The transmission of sub-terahertz electromagnetic waves is controlled by an electric field-induced rotation of the nematic axis of the 5CB molecules. The measured extinction ratio of the switch is 13.3 dB at 91GHz. Experimental results are in good agreement with simulations.