Abstract: An optical sensor for three dimensional shapes includes a laser that produces a lamellar plane beam which illuminates the surface of an object. The lamellar plane beam produces a curvilinear luminous trace that is scanned by at least one video camera, to produce information that is then converted into digital data representing pixel coordinates. The sensor includes a lightbox having a common housing that is positioned a short distance above the object to be scanned. The lightbox housing also includes a laser source that produces a collimated rectilinear beam and an optical device for converting the rectilinear beam into the lamellar plane beam. The lightbox housing also includes a device for lengthening the optical path of the lamellar plane beam, comprising two fixed plane mirrors in face to face relationship to produce a plurality of reflections between a beam entry point and a beam exit point of the lightbox.