The polarization state of the optical electromagnetic field lying several nanometers above complex dielectric-air interfaces reveals the intricate light-matter interaction that occurs in the near-field zone. From the experimental point of view, access to this information is not direct and can only be extracted from an analysis of the polarization state of the detected light. These polarization states can be calculated by different numerical methods, well suited to near-field optics..

Thanks for your reply @ Biswas yes i know but polarization makes image??? and which numerical method you are talking about??

I can imagine many replies, depending on your particular approach to near field calculations. I remember two features of these maps that have interested me in the past. One is the strong curvatures of the lines drawn by the electric field arrows, indicating possible magnetic oscillators, or, more generally, a particular oscilating mode. With non-nul conductivity this is informing also of the local currents. The other is the location of regions with high density oflines, for its potential for interaction with a neighbouring object, something that is important in many techniques, or sometimes to identify a resonant condition...