Surface roughness parameters measurements by Digital Holographic Microscopy (DHM)

Digital Holographic Microscopes (DHM) allows the capture of all the information necessary to provide 3D phase measurements with a nanometer vertical resolution in a single image acquisition. DHM images provide measurements of the surface topography which can be used for surface analysis, roughness measurements for example. In this paper we present roughness measurements on micro-balls of different sizes for which numerical procedures are applied for form factor and waviness removal. DHM thus permits quantitative measurements of the roughness on a 2 dimensional area allowing enlarged information compared to common profilometers. Mean roughness of 5 to 30 nm are measured and compared to values obtained by a profilometer.