Double-ended Fizeau interferometers with phase-stepping evaluation for dimensional measurements

摘要

Material standards of volume or length can be measured with highest accuracy, when double-endedFizeau interferometers with phase stepping evaluation are used. The technique is suitable for regularbodies with reflecting flat or spherical surfaces. For the measurements, the bodies are included in theinterferometer system, so that light waves of appropriate wavefronts and known wavelengths candirectly be used for probing their surfaces. Interferometers for measurement of spheres and cubesincluding the necessary servo control units and data evaluation systems are described. Experimentalmaterial is presented to demontrate the properties of a special Fizeau algorithm and the features of aparticular interferometer.