Unveiling Exciton‐Plasmon Polariton Coupling Regions via Polarization‐Enhanced Optical Nanoscopy

Abstract Nanoscale accuracy in single‐molecule localization is a crucial function in wide‐field super‐resolution optical microscopy by surpassing the diffraction limit. However, achieving high localization accuracy remains a challenge due to limitations in the signal‐to‐noise ratio and the complexity of molecular environments. In this study, a novel polarization‐enhanced single‐molecule localization microscopy (P‐SMLM) technique is introduced, incorporating dynamic polarization modulation to enhance the localization accuracy significantly. By modulating the polarization state of the excitation light, the technique leverages molecular sparsity, enabling more precise position determination. A 16 fold improvement in localization accuracy is shown experimentally compared to conventional methods, particularly under low signal‐to‐noise conditions. Moreover, the P‐SMLM enables direct visualization of exciton‐plasmon polariton coupling regions at room temperature. This findings highlight the potential of polarization modulation as a versatile tool for advancing single‐molecule localization microscopy (SMLM) accuracy and its applicability in diverse scientific and technological fields.