Microscopic ellipsometry: Imaging monolayer on arbitrary reflecting supports

This paper discusses some aspects of imaging nullellipsometry. Our experimental set-up is based on a simple modification of a conventional nullellipsometer providing the means of imaging monolayers on any reflecting support (metals, ceramics, liquids, etc.). The lateral resolution is of the order of approximate to 1 mu m, and the known sensitivity of ellipsometry to changes in thickness (approximate to Angstrom) and orientational order is preserved. The set-up allows the separate determination of real and imaginary part of each element of the Jones matrix of the sample. Several images of a variety of samples were recorded in order to demonstrate the power of the method: (1) a self-assembled monolayer photochemically patterned by UV radiation, (2) a system consisting of a liquid crystal showing a well-defined multilayer formation at the air-water interface, and (3)the organization of D,L-alpha-dipalmitoyl-phosphatidyl-ethanolamine at the oil-water interface.