Providing noncontact metrology for commercial and high-end optical surfaces, the PLu apex from Sensofar-Tech S.L. is a compact 2-D profiling system designed to measure any optical surface, including aspheric and free-form optics. Based on the company’s core confocal profilometry technology, it uses a proprietary tracking algorithm, a high-numerical-aperture microscope objective and structured illumination to determine the position of the sample surface. The system reconstructs the surface profile by tracking horizontal movement of the objective using a high-resolution air-bearing stage, then collates this data with the vertical position of the sensor head that keeps the surface in focus. Horizontal resolution is 1 nm, and vertical resolution is 0.5 nm.