Claus Richter

Optimization of white light interferometry on rough surfaces based on error analysis

Summary White light interferometry can be used to measure the shape of rough surfaces. At rough surfaces, the measuring uncertainty in principle cannot be better than the surface roughness, which is commonly in the range of 1 micron. Hence, the requirements for the hard- and software components of the instrument are not as high as for interferometry in the nanometer regime. An analysis of the dominant error sources allows the design of an “optimal” sensor with a measuring uncertainty as small as physically possible, with components as good as necessary and as simple as possible.

Deflektometrie macht der Interferometrie KonkurrenzDeflectometry Rivals Interferometry

Zusammenfassung Die Deflektometrie ist eine in den letzten Jahren neu entwickelte Methode zur Vermessung glatter Oberflächen. Sie gestattet es, auch auf Freiformflächen Höhenvariationen im Nanometerbereich zu vermessen. Um die positiven Eigenschaften der Deflektometrie zu verstehen, betrachten wir die physikalischen Grenzen sowie informationstheoretische Aspekte. Abschließend wird die Vielseitigkeit der Deflektometrie anhand von Anwendungsbeispielen demonstriert.

Deflectometry Challenges Interferometry: 3-D-Metrology from Nanometer to Meter

We will discuss deflectometry from the physicist’s and from the information theoretical point of view. The intrinsic features of deflectometry -incoherence, source encoding, high dynamical range, simplicity, and scalability- enable new sensors and unexpected applications. (Digital Holography and Three-Dimensional Imaging, 2009). Download original .PDF file here: