Tiny but huge: How precision is being redefined in Thuringia

A mirror as large as a dining table—and manufactured with such precision that its surface shows virtually no deviations on the atomic scale. What sounds like a thought experiment is precisely the goal of a new research project in Thuringia.
Until now, the world of high-precision nanostructures has ended surprisingly abruptly: even the most advanced processes reach their limits at an edge length of about 30 centimeters. For many applications in cutting-edge research, that is too small. Because in this field, it is not only precision that matters, but also surface area.
A research consortium from Jena and Ilmenau now aims to push this boundary—and drastically so. Using a novel machine, nanostructures are expected to be produced in the future on surfaces of up to one square meter. In his role as group leader at the Institute of Applied Physics (IAP), Prof. Uwe Zeitner plays a significant part in the project’s overall success. He receives close support from other researchers in the IAP’s Micro-Nano Group; at the same time, he is also involved in the research work at the Fraunhofer IOF. The project is funded by the German Research Foundation (DFG) with approximately four million euros.

When Size Becomes a Problem

In the world of nanotechnology, precision is routine—as long as the components remain small. But the larger a surface area becomes, the more difficult it is to maintain that precision. Even minimal influences can distort the result: tiny temperature fluctuations, barely measurable vibrations, or material stresses.
What is barely noticeable in the lab becomes a real problem on a meter scale.
This is exactly where the project comes in. The planned 3D nanolithography and nanomilling machine is designed to process components with dimensions of up to 1×1×0.2 meters—while achieving a level of precision that has previously only been possible on significantly smaller surfaces.
Such requirements are relevant, for example, for the spectrometer gratings used in the instruments of the next generation of large telescopes, such as the Extremely Large Telescope of the European Southern Observatory (ESO).

Precision Beyond the Visible

The target accuracy is particularly ambitious: the positions of the nanostructures are to be controlled with a precision of up to 20 picometers. This corresponds to 10^(-12) meters—an order of magnitude significantly smaller than the diameter of an atom.
The goal here is not to “place” individual atoms. Rather, the key is that positions can be set in an extremely stable, reproducible, and controlled manner—even across the large distance of a 1-meter component.
In addition, the researchers aim to limit the deviation of the generated structural dimensions to less than 10 nanometers—and this, too, across the entire area of one square meter.

A Combination of Specialized Knowledge

Achieving this level of precision requires more than just a single technological breakthrough. The planned machine is the result of the synergy between several highly specialized approaches.
The Fraunhofer Institute for Applied Optics and Precision Engineering IOF and the Institute of Applied Physics in Jena are contributing their expertise in 3D nanolithography. The Technical University of Ilmenau complements this with its many years of experience in system development for high-precision positioning and measurement technology.
Together, they are working on solutions to problems that cannot be easily scaled:
How do you stabilize a system against the slightest vibrations?
How do you ensure that materials expand minimally due to temperature?
And how can you even measure accurately in areas below the atomic scale?
This is to be achieved through a system concept that combines various innovative approaches from interferometry, laser-based length measurement, and opto-mechanical stabilization and scales them to the required size. In particular, the expertise of our colleagues from Ilmenau in the field of ultra-precise measurement systems will be utilized for this purpose.

Why this is important

The new machine is designed for applications where every detail counts. In fusion research, for example, large gratings are needed to precisely reflect extremely high laser powers. Even the slightest irregularities can lead to energy losses or damage.
In gravitational wave research, the situation is even more extreme: there, even minimal distortions of space must be measured. The quality of the optical components used directly determines how sensitive the detectors are. The new lithography system is intended to enable novel mirror designs that exhibit significantly lower thermal noise, thereby substantially improving the sensitivity of the entire gravitational wave detector.

The two institutes in Jena are already involved in preliminary development for projects such as the planned Einstein Telescope, a next-generation gravitational wave detector. The new machine could enable the production of components that were simply impossible to manufacture until now.

A Long-term Project

First, during a three-year conceptual phase, the researchers will develop the fundamentals and key subsystems. Afterward, they plan to demonstrate step by step that the targeted precision levels can indeed be achieved across the entire 1 m² surface.
The finished machine could be up and running at Fraunhofer IOF by around 2032.
The project will officially kick off in May 2026 at the Quantum Photonics trade fair in Erfurt. There, the participating partners will present their vision to the public for the first time.
It is still an ambitious undertaking. But if successful, it could fundamentally change the manufacturing of high-performance optical components—and thereby expand the possibilities in some of the most challenging research fields of our time.