Surface Plasmon Microscopy Versus Optical Microscopy: Ez Dominates in SPM

Abstract

Objective-coupled surface plasmon microscopy (SPM) possesses extremely high similarity with conventional optical microscopy (OM) in both configuration and theoretical model (graphic abstract (a)). And there is a common misunderstanding in SPM that all the three polarization components Ex, Ey, and Ez of the focused beam contribute to excitation of SPs, similar as the situation in OM that all the polarization components generate image contrast. The present work clarifies that 'only Ez excites SPs' for the first time. We theoretically prove this issue and further give related phenomena about selffocusing and resolution of SPM (graphic abstract (b)) as evidences.