Abstract: An optical system for analyzing and correcting wave fronts comprising a deformable mirror for correcting wave fronts and a system for analyzing and detecting phase distortion, an interferometer with lateral duplication constituting the analysis system, receiving the wave front for analysis and duplicating it and deducing from two neighboring wave fronts obtained signals to control deformation of the deformable mirror, wherein this lateral duplication interferometer is a polarization interferometer consisting of a Wollaston double-refractive biprism with an angle .theta., the two prisms being assembled head to tail and cut parallel to the crystallographic axis such that the respective axes are parallel and perpendicular to the edges of the prisms, a polarizer and an analyzer on either side of the biprism and an oscillating optical member on the path of the biprism.

Abstract: A method for measuring the bonding power of an adhesive material, particuly a sheet material comprising fibres impregnated with a glue. After having applied against the material the face of a totally reflecting prism the index of refraction of which is lower than that of the glue, a force is exerted which tends to bring apart from each other the prism and said material, the value of the force corresponding to the separation is determined and the quotient is made of said force by the value of the contact area measured at the moment of the separation from the light totally reflected by said face.