Abstract: A device is provided for checking the positioning and/or the focusing of a focused light beam. This integrated optical device for checking the positioning and/or the focusing of a focused light beam having an integrated optics guidance structure includes a multimode waveguide or an array of monomode guides distributed so as to be able to exchange energy. The waveguide or monomode guide array is integrated into the guidance structure and is able, when the distribution of the light beam directed at the input of the guide or the array of guides has a single maximum, to transform the distribution into a distribution having N (N.gtoreq.2) maxima at the output of the guide or array of guides. The guideance structure fruther includes a detector for measuring the distribution of the intensity at the output of the waveguide or monomode guide array, and an analyzer for analyzing the intensity distribution connected to the detector.