Stefan Bäumer

“I really see optics as an enabling technology. My colleagues and I are experienced in many optical technologies that we can use to build instruments and complete systems, together with experts in other disciplines (such as mechanics, electronics and data processing).

We translate the customer’s requirements into optical functions and, ultimately, into lenses and mirrors. Optical measurement principles are non-contact, fast, and so accurate that optics is a logical starting point; so it all starts with optics.”

Revolutionary eye scanning technology

“One exceptional project I’ve worked on involves a handheld camera that enables us to measure the quality of a person’s retina. The instrument we designed with our mechanics colleagues is revolutionary, because it is relatively cheap to produce and easy to operate, even by untrained staff.

In addition, what makes the camera really special is that, in time, aside from eye diseases, we will probably be using it to detect cardiovascular diseases or brain diseases for which the patient is predisposed. In the future, you won’t just get your eyes tested at the optician’s, you will also find out whether your heart is in order and whether you are at risk of developing Alzheimer's or Parkinson’s.”

Ground-breaking work in semiconductor technology

“TNO has quite a pre-eminent position in terms of its optics expertise. We have found ways of applying some really great technologies, especially for the aerospace industry. For example, they are used in earth observation satellites, in applications such as monitoring the concentration and distribution of atmospheric CO₂. We are also making great progress in the field of semiconductors. My team works closely with ASML, one of the leading players in the semiconductor industry.”

Building bridges

“In addition to my work as an optical designer at TNO, I am also a Principal Scientist. At TNO, Principal Scientists share responsibility for the development of new technologies. There is a lot going on in optics. My job is to ensure that we only push the right technological developments. Every month, the Principal Scientists hold a meeting to build bridges, strengthen each other in practical ways and to collectively devise ground-breaking solutions. That approach is really unique to TNO. We are neither an optical company, nor a mechanics company, nor a defence organization. No, we’re TNO. We do it all.”

There is a great need for optics

“Optics will become increasingly important in the upcoming years. Take one of my main areas of interest, for example, the semiconductor technology. Chips continue to shrink and to become even more energy efficient, which is a wonderful development. However, this does make it difficult to take measurements. For that, you need really top-class optics. We are already testing optical measuring principles that will benefit the semiconductor industry and other markets in the future.”

PhD supervision

• Jonas Berzins, Marie Curie project NOLOSS, graduating at the Friedrich Schiller University, Jena

Top publications

• Jonas Berzinš*, Stefan Fasold, Thomas Pertsch, Stefan M. B. Bäumer, and Frank Setzpfandt, “Submicrometer Nanostructure-Based RGB Filters for CMOS Image Sensors”, ACS Photonics 2019, 6, 4, 1018–1025
• Jonas Berzinš, Simonas Indrišiūnas, Koen van Erve, Arvind Nagarajan, Stefan Fasold, Michael Steinert, Giampiero Gerini, Paulius Gečys, Thomas Pertsch, Stefan M. B. Bäumer, Frank Setzpfandt, “Direct and High-Throughput Fabrication of Mie-Resonant Metasurfaces via Single-Pulse Laser Interference”, ACS Nano 2020, 14, 5, 6138–6149
• Van der Post, Sietse Thijmen [NL]; Baumer Stefan; Michael Bruno [DE]; Van Voorst Peter Danny [NL]; Tukker Teunus Willem [NL]; Zijp Ferr [NL]; Nienhuys Han-Kwang [NL]; Van den Eerenbeemd Jacobus Maria Antonius [NL], “Optical systems, metrology apparatus and associated methods”, WO2019042809 (A1)