Abstract-High extinction ratio and low transmission loss thin-film terahertz polarizer with a tunable bilayer metal wire-grid structur

                                                                       

                                                                           
                                         

      
Zhe Huang, Edward P. J. Parrott, Hongkyu Park, Hau Ping Chan, and Emma Pickwell-MacPherson  »View Author Affiliations

Optics Letters, Vol. 39, Issue 4, pp. 793-796 (2014)
http://dx.doi.org/10.1364/OL.39.000793

http://www.opticsinfobase.org/ol/abstract.cfm?uri=ol-39-4-793

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.