Now, the quality of the illumination starts playing a role here. Various tricks can be employed if one decides to fight for the resolution further. There are quite moderate solutions, such as the use of an immersion material, or additional spatial filtering in a confocal microscopy. A more universal way of immersion microscope is to use a so-called solid immersion lens . A little hemisphere made of a transparent high refraction index material is placed on a sample, so that the bottom surface of the hemisphere is in the near-field distance from the sample surface.
Image contrast is the second important point of the whole microscopy business.
Everyone who worked with magneto-optical signals from surfaces or thin films will guess that the expected contrast is quite low. Let s see, what the problems are. So everything looks trivial. To understand whether this is really trivial, let us estimate the amount of light reaching the detector. The analyzer axis is exactly perpendicular to the polarization after the black domain.