A thin-film terahertz polarizer is proposed and realized via a tunable bilayer metal wire-grid structure to achieve high extinction ratios and good transmission. The polarizer is fabricated on top of a thin silica layer by standard micro-fabrication techniques to eliminate the multireflection effects. The tunable alignment of the bilayer aluminum-wire grid structure enables tailoring of the extinction ratio and transmission characteristics. Using terahertz time-domain spectroscopy (THz-TDS), a fabricated polarizer is characterized, with extinction ratios greater than 50 dB and transmission losses below 1 dB reported in the 0.2–1.1 THz frequency range. These characteristics can be improved by further tuning the polarizer parameters such as the pitch, metal film thickness, and lateral displacement.
© 2014 Optical Society of America
Original Manuscript: November 13, 2013
Revised Manuscript: December 21, 2013
Manuscript Accepted: December 29, 2013
Published: February 5, 2014
Zhe Huang, Edward P. J. Parrott, Hongkyu Park, Hau Ping Chan, and Emma Pickwell-MacPherson, "High extinction ratio and low transmission loss thin-film terahertz polarizer with a tunable bilayer metal wire-grid structure," Opt. Lett. 39, 793-796 (2014)