Double Wire-Grid Terahertz Polarizer on Low-Loss Polymer Substrates

A double-wire-grid polarizer was fabricated on both sides of a low-loss polythene film by simple electroplating and photolithographic micro-processing techniques. The performances of the polarizer were measured using a terahertz time-domain spectrometer (THz-TDS). The transmittance is more than 70% and below 2% in the parallel and perpendicular directions of the polarizer, respectively. The extinction ratio is better than 22 dB in the broad frequency range of 0.5-3 THz, which is higher than the conventional free-standing polarizer in the high frequency region.