Promise and challenge of DUV speckle interferometry

The paper explains the benefits and the application limits of micro speckle interferometry (MSI) and it shows the potential for improvements when a deep UV laser source is used. For the experiments, a new deep ultraviolet micro speckle interferometer (DUV-MSI) was designed operating at 266 nm of wavelength. The implemented optics enables for the measurement of both, in-plane and out-of-plane movements on the microparts. A number of practical examples are shown in the paper in order to illustrate the advantages of a shorter wavelength in speckle interferometry.