Abstract-Robust and accurate terahertz time-domain spectroscopic ellipsometry

Xuequan Chen, Edward P. J. Parrott, Zhe Huang, Hau-Ping Chan, and Emma Pickwell-MacPherson

https://www.osapublishing.org/prj/abstract.cfm?uri=prj-6-8-768

In this work, we show how fiber-based terahertz systems can be robustly configured for accurate terahertz ellipsometry. To this end, we explain how our algorithms can be successfully applied to achieve accurate spectroscopic ellipsometry with a high tolerance on the imperfect polarizer extinction ratio and pulse shift errors. Highly accurate characterization of transparent, absorptive, and conductive samples comprehensively demonstrates the versatility of our algorithms. The improved accuracy we achieve is a fundamental breakthrough for reflection-based measurements and overcomes the hurdle of phase uncertainty.

© 2018 Chinese Laser Press

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