Optics Technology 

TL;DR: In this paper, a new laser image called speckle interferometer, a device used for looking at vibrational modes on defusely reflecting surfaces, has been designed, making it possible to provide a reference field in the instrument that is substantially free from spurious pattern.

TL;DR: In this paper, a method for determining the displacement component in a chosen direction on the surface of a deformed object is described, based on hologram interferometry and uses two illumination waves.