Mueller matrix polarimetry of advanced structures with special optical response

Abstract

Mueller matrix polarization-based techniques allow for contactless and non-destructive probing of material parameters, including refractive index, layer thickness, anisotropy, and magneto-optic effects. Among these techniques, Mueller matrix spectroscopic ellipsometry (MMSE) is well-acclaimed for its sub-nanometric precision and versatility in thin-film analysis. However, despite its advantages, MMSE is underutilized in specific areas of molecular chemistry, particularly in chiroptical spectroscopy. This underutilization can be attributed to the perceived complexity of the Mueller matrix formalism, which may discourage newcomers and interdisciplinary applications despite its clear benefits.

This dissertation focuses on the application of commercially available Woollam RC2-DI Mueller matrix spectroscopic ellipsometer and addresses two central objectives. First, it demonstrates MMSE’s potential for studying chiral materials with intrinsic optical activity. By carefully selecting illustrative chiral systems - from glucose solutions and complex chelate compounds to z-cut quartz - and clearly explaining the underlying theoretical framework, the thesis shows how MMSE bridges conventional chiroptical methods and comprehensive polarization-response analyses. The findings indicate that MMSE can detect chiroptical signals across an ultraviolet-to-near-infrared range while exceeding the system’s nominal Mueller matrix sensitivity limit by over 80 %. Moreover, it successfully captures dynamic, time-dependent processes, such as glucose mutarotation, achieving approximately 99 % agreement with conventional analytical methods and surpassing them by providing a glucose gyration tensor. The thesis also highlights MMSE’s ability to differentiate subtle circular birefringence from dominant linear birefringence, enhancing the characterization of bulk quartz waveplates. This versatility demonstrates its relevance in both academic and industrial contexts.

Second, the work emphasizes MMSE’s effectiveness in advanced thin-film characterization. Collaborations with international research groups on spintronic terahertz emitters and two-dimensional materials illustrate that parameters derived from MMSE are vital for correct theoretical simulation and precise device optimization. This research led to nearly a 250% increase in terahertz emission efficiency through cavity-enhanced designs and clarified the transition between semiconducting and semimetallic regimes in layered PtSe2.

Finally, the dissertation offers best-practice guidelines for integrating MMSE into various experimental settings. It connects the Mueller matrix formalism with conventions familiar to optics, chemistry, and materials science in a more digestible manner. By combining theoretical foundations with applied case studies, the dissertation positions MMSE as a powerful, sensitive, and accessible tool for investigating complex polarization phenomena, making it appealing and valuable for researchers from diverse backgrounds.