布鲁斯特角显微镜原理和应用（English）

INTRODUCTION Reflection of ligth from surfaces is part of our daily experience. However, an amazing property of optics is the possibility of having zero reflection. In more detail no reflection occurs from a clean and perfect interface illuminated under a unique angle of incidence with p-polarized light. This well-understood phenomenon is described by Brewster´s law providing the so called Brewster’s angle for the involved optical media. Any subsequent changes of the optical properties at the interface will lead to reflection. This fact is the basis of Brewster angle microscopy, a recent technique for the study of nanofilms at the water/air interface or at the surface of other transparent nonadsorbing dielectric substrates. Even just with a monolayer on an interface Brewster’s law is not fullfilled and the covered part of the surface reflects light although with very low intensity. By increasing the intensity of the illumination the contrast between the covered and the clean part of the surface can be enhanced. By using a microscope optic and a CCD-detector high contrast images of the lateral morphology of the layer can be taken. Typical fields of application are life sciences, colloid and surface chemistry and materials research.