Combined optical and tactile measurement of aspherical and freeform optics with reference fiducials up to 1000 mm diameter

For aspherical and freeform surfaces not only the surface form error but also the position of the surface relative to external references is . These fiducials can be markers, the outside edge, plane orthogonal surfaces, dowel pin holes etc. The NMF non-contact measurement machine range for freeform optics by Dutch United Instruments (DUI) can be employed for measurements during the entire production process, measuring ground, polished and coated optical surfaces. DUI recently introduced the NMF1000 S, capable of measuring aspherical and freeform surfaces up to 1000 mm diameter. This platform has now been extended with a tactile probe option to measure reference features that are not measurable with the optical probe. This allows for nanometer level characterization of surface form, mid-spatial content and absolute position relative to the mechanical reference points. . Tactile probe results are discussed in this paper.