Group Highlights

Over the last 25 years the group is specialized in the design and realization of complex optical, mainly Infra Red, instrumentation. The IR wavelengths add tremendously to the complexity of the instruments. Because of the utmost importance to reduce the background radiation within the instrument, because infra red wavelengths equal to heat radiation, the whole instrument needs to be cooled to and even below 80 K (-193 ˚C). A so called cryogenic instrument is a complex system on its own, let alone a highly accurate optical system at cryogenic temperatures.

Because of the complex nature of IR (thus cryogenic) instrumentation many different engineering skills need to be embedded within the design team. Close collaboration is demanded between the various disciplines, from optical engineering, via mechanical and thermal engineering, to manufacturing and test engineering. All of these disciplines are equally important and thus are all involved in all stages of the development process of the instrument.


The optical instrumentation group was originally founded in 1982 as collaboration between the Kapteyn Institute (Groningen) and the Leiden Observatory, merging the technical groups of these two university institutes. Until 1996 the group was located at the Kapteyn Observatory in Roden, the small observatory of the Kapteyn Institute near Groningen.

With the advent of 8-10 meter class telescopes the scale and complexity of instrumentation projects increased significantly. It became clear that these new challenges could only be met by embedding the optical instrumentation work in a broader technological environment. The optical group therefore moved to Dwingeloo where it became part of ASTRON. With the addition of ASTRON mechanical engineers a new team was born, dedicated to complex optical instrument development. Re-evaluation of the goals and future of ASTRON resulted in an emphasis towards the radio astronomy and instrumentation and in 2008 NOVA adopted the now called VIRIN group, largely funded by NOVA, but hosted by ASTRON.


The complex nature of cryogenic, highly accurate optical instrumentation requires a multi disciplinary team with knowledge of cutting edge design expertise. Close interaction between the various disciplines, optical mechanical electrical thermal and test engineering, optical and mechanical fabrication, is most important at all stages of the instrument development. This multi disciplinary character is emphasized by the wide range of skills and competences within the group.

Modern design and engineering tools are available like ZEMAX for Optical design, Creo elements/Pro (formerly known as Pro/Engineer) 3D CAD/CAE, Creo Elements/Pro Mechanica for FEA and thermal analyses, MasterCAM for 3D-CAM including 5 axis simultaneous machining and various other software for calculations and simulations like MathCAD, MATLAB. Well equipped workshops are available for optical and mechanical fabrication and optical, mechanical and thermal (functional) verification. Additionally the group has good connections with the industry for specialist fabrication and verification, surface treatment and additional cryogenic facilities. The cleanroom allows clean and particle free assembly and verification for the best instrument quality. Thanks to the well structured quality and project management the group is able to develop instruments even conform the stringent space requirements.


Like the new observatories the size and complexity of modern astronomical instruments increases with the scientific need to detect fainter sources and to improve on previous observations. The majority of instrumentation is therefore built by international teams with international funding. There is close collaboration of the group with various national and international partners at universities, competence centers and (high-tech) industry. International partners are, amongst many others:

  • Commissariat à l'énergie atomique et aux énergies alternatives, CEA (Service d'Astrophysique SAp (Saclay, F))
  • Max-Planck-Institut für Astronomie (MPIA) Heidelberg, D
  • Max-Planck-Institut für extraterrestrische Physik (MPE) Garching, D
  • UK Astronomy Technology Center (UK-ATC) Edinburgh, UK
  • Rutherford Appleton Laboratories (RAL) Oxford, UK
  • European Space Research and Technology Centre (ESTEC). 

Many of the instruments are built for the European Southern Observatory (ESO), the Isaac Newton Group of Telescopes (ING) and the Eauropean Space Agency (ESA)

Within the Netherlands the group collaborates closely with:

  • The (astronomical institutes at the) dutch universities
  • The space research institute (SRON)
  • The technical physics institute (TNO)
  • Janssen Precision Engineering (JPE).
Design: Kuenst.    Development: Dripl.    © 2021 ASTRON