Abstract: An apparatus and method for measuring optically the position or angle of a variety of objects or arrays of objects, including cantilevers in scanning probe microscopy, micromechanical biological and chemical sensors and the sample or a probe in surface profilometry. The invention involves the use of one or more diffractive optical elements, including diffraction gratings and holograms, combined with conventional optical elements, to form a plurality of light beams, each with a selectable shape and intensity, from a single light source, reflect the beams off mechanical objects and process the reflected beams, all to the end of measuring the position of such objects with a high degree of precision. The invention may also be used to effect mechanical changes in such objects.