Chromatic confocal microscopy with microlenses

The main feature of the well-known technique of confocal scanning microscopy is that of optical sectioning. This capability allows threedimensional reconstruction of the topometry of technical surfaces, built up from a series of hundreds of depth discriminated height sections. Based on this fundamental principle, several confocal microscopes have been realized with high axial and lateral resolutions. For a drastically enlarged field and a significant reduction in measuring time, a chromatic confocal method using microlenses has been developed. When measuring an object the topography can be determined by 4 chromatic coded images and, in contrast to conventional techniques, there is no need for mechanical height stepping in the axial direction. For this reason real-time measuring has become possible. First results with this set-up are presented.