Dutch United Instruments (DUI) recently confirmed their tenth order for delivery in 2022. These orders include all products in their NMF product range, which are the NMF350 S, NMF600 S and NMF800 S. With this final order, DUI starts the year on a high note. Gerard van den Eijkel, managing director of DUI, is pleased with the result: “Our team has been working very hard on this design for the last couple of years. With these orders, we prove that the market is in need of a fast high-end metrology system for asphere and freeform optics. We were able to focus on perfecting the design and developing different sizes of the metrology tool. Being part of the Demcon group provides us all the operational support and resources for our growth.”
Five unique characteristics
The NMF products are each defined by five unique characteristics, making it one tool to cover all form metrology needs in modern high-end optical manufacturing. Firstly, the systems are universal, they can measure shapes from convex to concave and flat to freeform. Secondly, they can handle a large volume, up to 800 mm. In addition, they are accurate within an uncertainty of 15 nanometer rms. Furthermore, the systems are fast. They can setup and produce results within minutes. And finally, there is no contact between the probe and the object that is being measured. Rens Henselmans, chief technology officer at DUI, explains in detail how the NMF 600 S works in the video below.
Meeting TNO’s expectations
The NMF is the NANOMEFOS, a freeform metrology system that was developed by Eindhoven University of Technology and TNO, in collaboration with partners like VSL. Peter van Doorn, SPDT and metrology specialist at TNO, explains: “This was more like a prototype for the current NMF. The NMF is the next step.” TNO’s optics manufacturing department is involved in the manufacture of metal optics, which are mainly one-off freeforms and off-axis aspheres. They use the NMF600 S not only for final product qualification for their customers, but also for iterative correction of optical surfaces using MagnetoRheological Finishing (MRF). Here, the shape deviations measured by NMF600 S are used to control the MRF machine. According to Van Doorn the NMF meets the high expectations of TNO. “No product is the same. The specs are usually quite challenging, for both form and waviness. Our first tests show that the data from the NMF is within 1 nm rms compared to a laser interferometer measurement. The measurement data is used to shape-correct the optical surfaces with MRF and in our final report to the customer.”
Senior Research engineer Optics Manufacturing André Hoogstrate also is enthusiastic about the machine: “The machine is excellent, with a clear and functional user interface. The functionality of the software is constantly being expanded and when we have questions or issues, they are adequately addressed and resolved. TNO is constantly pushing the boundaries of manufacturing and measurement in the optical field, and we hope that the functionality of the NMF600 S can be further expanded.