Yang, HuiGijs, Martin A. M.2015-09-282015-09-282015-09-28201510.1016/j.mee.2015.03.072https://infoscience.epfl.ch/handle/20.500.14299/118871WOS:000357908700017A technique that allows direct optical imaging of nanostructures and determines quantitatively geometric nanofeatures beyond the classical diffraction limit by using high-refractive index glass microspheres is introduced. The glass microsphere is put on a nanostructure that is immersed in oil and collects the sample's near-field evanescent wave and transforms it into a propagating one, thereby generating a magnified image in the far-field which is recorded by a conventional oil-immersion microscope objective. Experimental results on nanostructures demonstrates a resolution of similar to lambda/4-lambda/7, where lambda is the illumination wavelength, by using a 60 mu m glass microsphere and a normal wideband halogen lamp as illumination source. A two-dimensional numerical study of the light propagation through a glass microsphere using finite element method (FEM) is performed, providing key insight into the microsphere's superior imaging capability. (C) 2015 Elsevier B.V. All rights reserved.NanometrologyOptical microscopySuper-resolutionMicrospheretext::journal::journal article::research article