White-light interferometry

The Surface Profile Analyzer utilizes white-light interferometry for studying the surface topography. White-light interferometry is an optical measuring technique and due to the relatively large distance between measuring instrument and test surface, there is no danger of damaging the sample compared to profiling systems that rely on some sort of stylus.

The increased amount of available parallel computation power provided by modern graphics cards enables highly sophisticated evaluation algorithms. Hence the Surface Profile Analyzer can process up to 500 GByte of image data with each scan and provide a height resolution of down to 0.1 nm using the extended phase-shift interferometry (EPSI) scan mode.

A significant advantage of white-light interferometry compared to other optical height resolving methods like focus variation or confocal microscopy is that the height (Z-direction) resolution is independent of the magnification factor of the used objective. The magnification factor only changes the lateral (X-Y-direction) resolution.