White-light interferometry with an extended zoom range

Optical sensors are designed usually for microscopic or for macroscopic app lications. White-light interferometry on the other hand enables high-resolu tion measurements to be made for small and for large fields. In this paper we present a flexible set-up that can be used for both microscopic and macr oscopic applications. The magnification can easily be changed in seconds an d the zoom range is greater than 160. This set-up is especially designed fo r the investigation of optically rough surfaces. A novel filtering techniqu e enables fast and accurate data acquisition and evaluation with standard h ardware components. Further we demonstrate results of roughness measurement s in different scales.