The confocal laser microscope enables the production of three-dimensional optical images of surfaces. The image is created by moving the very sharply defined focal plane vertically through the object. The lateral resolution is in the range of 1 μm, while the height resolution extends to a few nanometers. Within a few minutes, the method provides quantitative information on, amongst other things, the surface topography, roughness, step heights, pitch angles or particle sizes.
Compared to tactile profilometric methods, confocal laser microscopy is significantly faster and can also be used to image soft or unstable surfaces, such as polymers or powders. To a certain extent, it is also possible to measure through transparent cover layers and determine the layer thickness in this way. In addition to pure imaging, there are a variety of software tools available for obtaining the maximum amount of quantitative information from the images.
The 3D particle image also allows the statistical evaluation of particle diameters, particle shapes, and particle thickness.
The example of Vickers indentations shows that a quantitative determination of hole depths and aperture angles is possible.
Evaluation of line cross-section profiles from a point grid.