Nanoparticle size determination via through-focus scanning polarized microscopy.

Accurate qualitative and quantitative characterization of sub-micron nanoparticles with a high efficiency is highly desirable across a wide range of scientific and industrial applications. In this study, we introduce through-focus scanning polarized microscopy (TSPM) for the estimation of nanoparticle parameters, where physical properties of nanoparticles are related to in-focus and out-of-focus polarization-resolved images. The feasibility of TSPM is rigorously demonstrated through a combination of numerical simulation and experimental measurements. Owing to its practical advantages, TSPM is anticipated to emerge as a powerful and versatile tool for highly sensitive metrology of nanoscale objects in material sciences and semiconductor industries.