The first optical distance sensor offering true nm-uncertainty

Till now, every commercially available optical distance sensor does not (and fundamentally cannot) deliver nm-level uncertainty when measuring even slightly tilted surfaces, though spec sheets often suggest differently! The reason is that all common single point optical distance sensors suffer from strong tilt-dependency, resulting in measurement uncertainty in the µm-range, which is not good enough for ultra-precision CMMs and freeform measurement machines. Our sensor designs solve this problem by both preventing and correcting tilt dependent errors (patent pending), enabling tilt-robust measurements with nanometer-level uncertainty. Moreover, the proven response model allows us to match each sensor to specific measurement needs, and the primary range of 3 μm to 10 μm can be extended up to millimeters by addition of a servo and secondary measurement system while preserving nm-accuracy. As such, our sensor is applied in TNO's NANOMEFOS freeform optics measurement machine, enabling its state-of-the-art accuracy.