Intensities (IMAGE) Physikalisch-Technische Bundesanstalt (PTB) Caption Intensities of the interferences of common Fizeau interferometers, in this example calculated for a reference surface with a reflectivity of 0.5 and test sample surfaces with varying reflectivity between 0 and 100% and a variation of the distance d between test sample and reference piece over a wavelength (λ = 633 nm). The new method avoids the strong dependence of the intensity profile and the contrast on the reflectivity of the test sample's surface. Credit PTB Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.