Abstract
Near-field microscopy is a tool for characterizing and imaging materials and components. In this work, microscopy bench was developed in the millimeter-wave range. In order to extract modulus and phase information, an IQ mixer is used, coupled with synchronous detections. Bow-tie probes are used to focus the field on the sample. Special attention has been paid to characterizing and minimizing the imperfections of this experimental set-up. A near-field dipole-material interaction model has been developed. Our measurements can reach subwavelength resolutions of a few micrometers, i.e. λ/2500. This system can also be used to produce subsurface images of components by taking advantage of near-field properties. An internal component structure was observed under a 13µm layer of resin. Finally, calibration procedures have enabled us to erase the impact of our probes on our results and to get closer to the physical values of the materials under test.