Nanometre-accurate form measurement machine for E-ELT M1 segments

To enable important scientific discoveries, ESO has defined a new ground-based telescope: the European Extremely Large Telescope (E-ELT). The baseline design features a telescope with a 39-m-class primary mirror (M1), making it the largest and most powerful telescope in the world. The M1 consists of 798 hexagonal segments, each about 1.4 m wide,...

Design of an E-ELT M1 segment measurement machine with nanometer accuracy

The baseline design of the European Extremely Large Telescope features a telescope with a 39-meter-class primary mirror (M1), consisting of 798 hexagonal segments. A measurement machine design is presented based on a non-contact single-point scanning technique, capable of measuring the form error of each segment with nanometer uncertainty, fast,...

The TROPOMI telescope: Design, fabrication and test of a freeform optical system

In this paper, we discuss the two-mirror pushbroom telescope for TROPOMI. Using freeform optics, it has unprecedented resolution. The complete cycle of freeform optical design, analysis, manufacturing, metrology and functional test on a breadboard setup is described, focusing on the specific complexities concerning freeforms. The TROPOMI flight...

Manufacturing of high precision aspherical and freeform optics

Aspherical and freeform optical elements have a large potential in reducing optical aberrations and to reduce the number of elements in complex high performance optical systems. However, manufacturing a single piece or a small series of aspherical and freeform optics has for long been limited by the lack of flexible metrology tools. With the...

Manufacturing of high precision aspherical and freeform optics

Aspherical and freeform optical elements have a large potential in reducing optical aberrations and to reduce the number of elements in complex high performance optical systems. However, manufacturing a single piece or a small series of aspherical and freeform optics has for long been limited by the lack of flexible metrology tools. With the...

The NANOMEFOS non-contact measurement machine for freeform optics

Aspherical and freeform optics are applied to reduce geometrical aberrations as well as to reduce the required number of components, the size and the weight of the system. To measure these optical components with nanometre level uncertainty is a challenge. The NANOMEFOS machine was developed to provide suitable metrology (high accuracy,...

Nanometer level freeform surface measurements with the NANOMEFOS non-contact measurement machine

Applying aspherical and freeform optics in high-end optical systems can improve system performance while decreasing the system mass, size and number of required components. The NANOMEFOS measurement machine is capable of universal non-contact and fast measurement of aspherical and freeform optics up to Ø500 mm, with an uncertainty of 30 nm (2σ)....