Work

Optimized Choice of Light Incidence Angles for the Determination of Optical Constants from Strongly Absorbing Thin Solid Films in a Narrow Spectral Range

Year: 2026

Type: article

Abstract: The determination of the linear optical constants of solids is an important part of solid state optical characterization. Reflection spectroscopy and ellipsometry of surfaces or thin solid films represent established techniques to access those optical constants, however, they may suffer from an ambiguity of the obtained optical constants. We discuss methods for identifying the physically meaningful solution from the solution multiplicity, making use of a proper combination of independent measurements. Elaborating contours of constant reflectance (iso-reflectance curves) facilitates reliable identification of correct optical constants. A numerical criterion is further provided to select suitable combinations of measurements. The procedure is demonstrated in application to simulated spectra of a Nb2O5 film in the spectral region where the onset of the fundamental absorption edge is observed.

Source: Solids

DOI: 10.3390/solids7030027

Authors: Steffen Wilbrandt, Olaf Stenzel

Institutions: Fraunhofer Institute for Applied Optics and Precision Engineering, Friedrich Schiller University Jena

Language: English

Topic: Optical Polarization and Ellipsometry

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,207

Funder: Fraunhofer-Gesellschaft