Phase singularities generated by optical microstructures: theory and experimental results

In this paper, we present theoretical and experimental results of our investigations on high resolution interference microscopy. We were able to measure phase variations with a spatial resolution in the order of 10 nm. For this purpose, we have modified a classical interference microscope based on a Mach-Zehnder interferometer to obtain ultra-high resolution. The optical fields were generated by periodic optical microstructures. The measured optical phase distribution in the near-field compares very well with the results of rigorous diffraction theory.