Metasurface Optics With On-Axis Polarization Control for Terahertz Sensing Applications

Nowack, Thomas S.; Shah, Yash D.; Grant, James P.; Carranza, Ivonne Escorcia; Kenney, Mitchell G.; Faccio, Daniele; Wasige, Edward; Cumming, David R. S.

Abstract

Nondestructive testing (NDT) and imaging of materials with unknown properties are important applications of terahertz technology. Different contrast-forming methods are available to obtain diverse information on the imaged region, including intensity, color, phase, and polarization. Polarimetric imaging is relatively under-investigated owing to the difficulty in its implementation with complex optical arrangements. In this article, we present the design and monolithic fabrication of an anisotropic metasurface that incorporates several beam-forming functions in a single layer with high efficiency thus simplifying instrument construction. The probe beam generated by the metasurface consists of an orthogonally polarized pair of collinear Bessel beams that create a well-defined on-axis change of polarization. The metasurface is integrated into a polarimetric imaging microscope for 3-D beam profiling and sensing experiments at 2.52 THz. An analytical model to describe the on-axis polarization variation was found to be in excellent agreement with both finite-difference time-domain (FDTD) simulations and the experimental results. The setup was used to measure the refractive index and diattenuation of homogeneous sample regions in a proof-of-principle application. We anticipate this technology will find future applications in NDT and polarimetric imaging of polymer composites and 3-D profilometry of reflective surfaces.

Citation

Nowack, T. S., Shah, Y. D., Grant, J. P., Carranza, I. E., Kenney, M. G., Faccio, D., Wasige, E., & Cumming, D. R. S. (2023). Metasurface Optics With On-Axis Polarization Control for Terahertz Sensing Applications. IEEE Transactions on Terahertz Science & Technology, 13(4), 373-380. https://doi.org/10.1109/TTHZ.2023.3263648

• Journal Article Type: Article
• Acceptance Date: Feb 23, 2023
• Online Publication Date: Mar 31, 2023
• Publication Date: 2023-07
• Deposit Date: Nov 8, 2023
• Journal: IEEE Transactions on Terahertz Science and Technology
• Print ISSN: 2156-342X
• Electronic ISSN: 2156-3446
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 4
• Pages: 373-380
• DOI: https://doi.org/10.1109/TTHZ.2023.3263648
• Keywords: Electrical and Electronic Engineering; Radiation
• Public URL: https://nottingham-repository.worktribe.com/output/22726815
• Publisher URL: https://ieeexplore.ieee.org/document/10089514