Fischer, EdgarDalhoff, ErnstIttner, ThomasKreuz, SilkeTiziani, Hans J.2011-03-212016-03-312011-03-212016-03-311993366722484http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-61828http://elib.uni-stuttgart.de/handle/11682/4408http://dx.doi.org/10.18419/opus-4391For interferometric distance measurements on rough surfaces multiple wavelength interferometry is a powerful tool. It allows to reduce the sensitivity and to extend the range of unambiguity for interferometric measurement. A new kind of a double wavelength heterodyne interferometer is presented which uses only one laser source which generates two wavelengths λ 1 and λ 2 simultaneously. The two different heterodyne frequency shifts of the double heterodyne interferometer (DHI) are achieved by combining an acousto-optical modulator (driven in suppressed carrier mode) with a fixed diffraction grating. In a first prototype a multi-wavelength HeNe laser was used as light source. The synthetic wavelength λ in this system is 55.5 μm and the resolution about 0.15 μm. Measurement results obtained with the setup described are presented.eninfo:eu-repo/semantics/openAccessOptische Messtechnik , Heterodyninterferometrie620conferenceObject2012-06-14