Abstract
We describe the profile measurement of a rough surface using Abramson interferometry. This interferometer is classified into an oblique incident interferometer with a right-angled prism close to a sample. For the automatic analysis of phase distribution of interference fringe, the phase shifting technique is applied. The reference phase is shifted by changing the refractive index between the prism and the sample. This system can measure the flatness of a rough surface and/or a steep uneven surface, with several ten micro-meters order, that can not be measured by conventional interferometers. The surface profile of a ceramic plate is measured to prove our method.
