Using polarized light for ellipsometry- and polarimetry-based analysis of biological samples

The exploitation of polarized light for the investigation of light-tissue interaction has evolved to a powerful approach for the analysis of various biological samples with potential to be established for rapid and reliable in vivo measurement in life sciences and medicine in future. We report on our work on the development and application of polarization-modulated spectroscopic ellipsometry and wide-field multi-wavelength Mueller matrix polarimetry for use cases as versatile as the detection of E.coli bacteria in microfluidic cells, the identification of multiple bacterial colonies in biofilms or the analysis of microstructural changes occurring in skin cancer or neurodegenerative disorders. We present our recent results along these lines and discuss the challenges with respect to miniaturization of the systems as well as towards in vivo and clinical application. Based on the results obtained so far, it is evident that the developed approaches open the potential for further application in medicine and the life science in future, in particular when combined with concepts from machine learning and artificial intelligence.