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Accurate THz ellipsometry using calibration in time domain

Zahra Mazaheri, Can Koral & Antonello Andreone
Scientific Reports
12,
7342
(2022)
Open access
CC BY 4.0
Accurate_THz_ellipsometry_using_calibration_in_time_domain_paper_image
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Research overview

This paper presents a customised terahertz time-domain spectroscopic ellipsometer (THz-TDSE) for accurate material characterisation over a wide range of incidence angles. The fibre-coupled system incorporates three free-standing wire-grid polarizers and an algorithm-assisted time-domain calibration method to compensate for non-ideal antenna response, polarizer alignment, angular positioning and THz beam optics. Measurements on solid and liquid samples demonstrated good agreement with conventional THz time-domain spectroscopy, showing the potential of calibrated THz ellipsometry for characterising highly absorptive materials that are difficult to investigate in transmission.

Key findings

  • Variable-angle THz time-domain ellipsometry over approximately 0.1–0.6 THz
  • Three free-standing wire-grid polarizers used as polarizer, analyzer and compensator
  • Algorithm-assisted calibration compensates polarization and optical-system non-idealities
  • Measurements validated on solid and liquid materials against conventional THz spectroscopy

10 µm Tungsten Wire-Grid Polarizer

Free-standing tungsten wire-grid polarizer used for broadband THz polarization control. Three polarizers were employed in the ellipsometer as polarizer, analyzer and compensator.
View product configurations
“For the control and detection of the polarization states we employ three substrate free Wire Grid Polarizers (WGP) from PureWavePolarizers Ltd”
Mazaheri et al.,
2022

Publication details

Journal

Scientific Reports

Volume

12

Issue

Article

7342

Published

2022

Research area

Instrumentation and Metrology

Application

THz ellipsometry and material characterisation

Licence

CC BY 4.0

Institution

University of Naples Federico II / INFN Naples

DOI

https://doi.org/doi.org/10.1038/s41598-022-10804-w

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