Some applications for distance metrology require absolute distance informations with a very high precision. Many optical methods are able to determine an absolute distance, but they are not precise enough to get an accuracy of a few nanometers. Interferometers are very precise due to the fact that they determine the phase of the light, but they have a very small range of unambiguity. To fit the requirements for a very precise but absolute distance measurement we do interferometry with synthetic wavelengths. Fiber optics introduces two additional advantages: firstly it allows the realisation of an interferometer with a small size sensor. This makes the adjustment of the interferometer very convenient. Secondly several sensors can be connected to the main unit for simultaneous measurements at different locations.
Print ISSN: 0171-8096
Volume: 67, 10/2000
Pages: 410