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.

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

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.

© 2014 Optical Society of America

Abstract-Apodization of terahertz Bragg gratings in subwavelength polymer fiber

Shu Fan Zhou, Laurence Reekie, Hau Ping Chan, Kwai Man Luk, and Yuk Tak Chow  »View Author Affiliations

http://www.opticsinfobase.org/ol/abstract.cfm?uri=ol-38-15-2807

We report on an apodization scheme for terahertz fiber Bragg gratings. The grating consists of only 90 ablated notches on two opposite sides of a subwavelength polymer fiber. The grating strength can be effectively tuned by controlling the longitudinal shift between the two-sided notches, and apodization can be achieved by applying an envelope profile. Side lobe suppression of 14 dB was experimentally observed when compared with an unapodized grating.

© 2013 Optical Society of America