Label free microscopy with enhanced localization performance based upon temporally modulated polarization

Recent microscopy techniques use nanoparticles as contrast agents that assist in realizing super resolved imaging of the inspected sample. While the sample itself is not labelled, its optical properties and form are revealed from the agent's location and movement. Gold nanoparticles are frequently used for compound cellular imaging due to their plasmonic resonance that occurs in the visible regime. While the effect dramatically enhances their effective absorption cross-section, additional enhancement techniques are still needed in order to reach adequate signal-to-noise levels and differentiate between adjacent nanoparticles. In this paper we demonstrate an effective way to image a sample using specialized eccentric gold nanoparticles while exploiting the polarization dependency of their plasmonic resonance. Temporal modulation of the illumination polarization induces a corresponding temporal flickering of the nanoparticles. The method enhances localization by eliminating noise that differs in frequency from the temporal modulation. Differentiation between nanoparticles is concurrently gained as the flickering is changed in relation with the angle between their eccentric axis and the polarization angle.