Diattenuation and Retardance Signature of Plasmonic Gold Nanorods in Turbid Media Revealed by Mueller Matrix Polarimetry

Abstract

Plasmonic gold nanorods (GNRs) are finding increasing use in biomedicine due to their unique electromagnetic properties, optical contrast enhancement and biocompatibility; they also show promise as polarization contrast agents. However, quantification of their polarization-enhancing properties within heterogeneous turbid media remains challenging. We report on polarization response in controlled tissue phantoms consisting of dielectric microsphere scatterers with varying admixtures of GRNs. Experimental Mueller matrix measurements and polarization sensitive Monte-Carlo simulations show excellent agreement. Despite the random 3D orientation and distribution of GNRs and strong multiple scattering background, significant linear diattenuation and retardance were observed that are exclusive characteristics of the GNRs, suggesting their potential as contrast agents for polarimetric imaging of biological tissue