Compensated Microsphere-Assisted Interference Microscopy

Abstract

We propose an experimental method in microsphere-assisted interference microscopy that makes it possible to reconstruct surface topographies as much with high quantitative depth accuracy as when the transversal feature sizes are smaller than the classical diffraction limit. The full-field super-resolution interference microscope consists not only of one glass microsphere in the object arm but also of a second similar microsphere in the reference arm. By compensating the sphere aberrations in the two interference arms, the spatial resolution appears to be considerably increased. The increase in the three-dimensional spatial resolution allows for the topography reconstruction of 300-nm-width grating lines and 200-nm-diameter transparent nanopillars.