“Our Goal Is to Compete in the Scientific Champions League”

_{Jena (Germany) | December 7, 2023}

For Andreas Tünnermann 2023 is a year of anniversaries: The internationally renowned laser scientist is not only celebrating his 60th birthday this summer. He is also looking back on 25 years now as chairholder and professor at the Institute of Applied Physics at the University of Jena, as well as 20 years as director of the Fraunhofer Institute for Applied Optics and Precision Engineering IOF. In more than two decades he has thereby significantly shaped and contributed to Jena as a location for optics and photonics. In a two-part interview with Professor Tünnermann we consequently take a look back, and at the same time shed light on the future.

In this first part, find out more about Andreas Tünnermann's first successes in Jena, about the special "spirit" of the traditional optics location at the Saale and about the mission-driven combination of excellent research and its application at Fraunhofer.

“Mr. Tünnermann, first of all we would like to express our sincere congratulations. 2023 is chasing one anniversary after another for you! There are surely many occasions for reminiscing. So, take us with you if you may: Which milestones from your beginnings in Jena and your career stand out especially for you?

I still remember my first visit to Jena well, which was directly after finishing my doctorate in Hannover in 1992. It was as part of preparations for a joint research project on fiber lasers with today's Leibniz Institute of Photonic Technology (IPHT) and the Laser Zentrum Hannover e.V. (LZH). Back then, in the winter of 1992/93, there was fog over Jena and it smelled strongly of coal stoves. But nevertheless - I could sense this special spirit that has always characterized the optics location.

The cooperation between Jena and Hannover grew and around one year later I first came into contact with the Institute of Applied Physics (IAP). The group integrated optics existed there, led by Andreas Rasch. In connection to the development of the so-called laser TV many joint projects came into being. At this time there were also the first scientific contacts to Fraunhofer IOF and Friedrich Schiller University Jena. Back then I got to know and value, amongst many others, Andreas Bräuer, Ramona Eberhardt, Gunther Notni, Norbert Kaiser, Wolfgang Karthe, Richard Kowarschik, and Roland Sauerbrey.

In 1997 I applied for the position of chair at the Institute of Applied Physics. I then took office on March 1, 1998, here at the Institute on the Beutenberg campus. A room in a dormitory was my first place of residence in Jena – immediately in the thick of it. There was a lot to do – one of the first activities concerned the planning and refurbishment of the MZV. We spend the first winter together without heating and with makeshift toilets. Nonetheless, the first scientific achievements were recorded. This includes the realization of fiber laser systems with diffraction-limited beam quality - a topic that Holger Zellmer and I brought from Hannover to Jena. The work on micro- and nano-optics in cooperation with E.-Bernhard Kley and the work on laser-matter interaction in cooperation with Stefan Nolte were also particularly fruitful. In these areas, we were quickly able to develop a strong impact and successfully position ourselves internationally.

What I remember particularly well from those early years were the appearances at international conferences, where we appeared in groups of students, doctoral candidates, and seniors - that forged a bond in our team and shaped our shared spirit. I also remember the many conversations with Lothar Späth. Like my PhD supervisor Herbert Welling, he instilled ‘entrepreneurial thinking’ into me.

And of course, among my personal career highlights is the appointment as director of the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in the year 2003, as well as the granting of the German Research Foundation’s (DFG) Leibniz Prize for my research on fiber lasers in 2005. I am especially proud of the three Deutscher Zukunftspreis (German Future Prize) of the German Federal President that we brought to Jena as a team in 2007, 2013, and 2020 – let’s see when we pull of the next coup.

But I was likewise especially moved to be bestowed with the Order of Merit of the Free State of Thuringia that not only honors my scientific achievements, but also my contributions to society. I’ve been lucky in my life that I was always able to work with people who also wanted to make a difference themselves – each publication, each dissertation, each doctorate but also each spin-off company became an important building block that has developed the site Jena even more strongly.

When you came to Jena in 1992 – what did you find here?

At the IAP I was able to connect with two groups already excelling within Germany on the topics of integrated optics as well as micro- and nano-optics. Back then, the groups were led by Andreas Rasch and E.-Bernhard Kley. We had the same goal – we wanted to transfer excellent research findings into application and create benefit. But there were many other players in the university’s surrounding environment, at non-university institutions and at many companies who shared this mission. So, a special project for me from the very beginning was the founding of the optics cluster OptoNet e.V., in which I was able to play an active role. Since then, I have been closely associated with the cluster, which has helped to promote Jena's visibility beyond Thuringia.

"I’ve been lucky in my life that I was always able to work with people who also wanted to make a difference themselves."

Andreas Tünnermann

How would you describe the cultural and scientific developments of your institutes since taking office? Or put another way: Which values and topics do you hope are associated with the public as well as internal perception of both institutes?

Our values – at Fraunhofer IOF as well as IAP – are shaped by dedication, creative drive, the promotion of young scientists and knowledge transfer! Our goal is to play in the (scientific) Champions League.

In the past few years, the topics have expanded from fiber laser technology and micro- and nanostructured optics to aspects of laser-matter interaction, freeform optics and nonlinear optics, up to quantum technologies. Behind that is always the drive to understand what users want: What are their challenges and how can we help them to find the best solution and real benefit? Of the utmost importance here is the qualification of junior scientists.

To promote diversity Falk Lederer and I founded the first international course of studies at the Friedrich Schiller University Jena in 2008 – the Abbe School of Photonics (ASP). 2018 Gerd Leuchs and I developed the concept further into a Germany-wide graduate school, the Max Planck School of Photonics (MPSP), whereby we have created an additional national network of excellence.

For me, becoming the director of a Fraunhofer institute has always been a dream – here, the mission-driven focus is on the connection between excellent research and its application. To implement this mission we have built infrastructure, expanded technology chains, and inspired people. Currently, we are updating our portfolio strategically to make a contribution to the second quantum revolution. With our competencies in the field of photonics we will enable pioneering applications.

What are some of the most important lessons that you have learned in your time at the institute?

There are a lot in almost three decades! First of all, many things take longer in reality than you think. That means always having a plan B or even plan C as a backup. But, of course, it is also important not to simply accept this, but to rethink processes, remove barriers - especially in administration - and establish an error management culture.

On the other hand, clearly, not to let our unique selling point out of sight: focusing on our core competencies, making progress and scrutinizing. Because each time the question has to be answered anew: What can our contribution be to this?

What role do you see for both institutes in the coming years regarding future scientific developments?

Developing solutions with light is a path we will continue to follow. At the forefront is always our goal to develop the best solutions for our partners in science and industry. We are facing a technological revolution in various areas. Thanks to recent advances in micro- and nanostructured optics, we find ourselves in a situation comparable to that of the 1960s, when the step towards microelectronics was taken - this will change the entire field. The opportunity to use quantum phenomena will soon provide us with fundamentally novel possibilities in areas such as communications, computing and sensors to develop the best solution for our partners and clients - we want to help shape this future.

"For me, becoming the director of a Fraunhofer institute has always been a dream – here, the mission-driven focus is on the connection between excellent research and its application."

Andreas Tünnermann

Those are big goals for the future! What other aspirations are you pursuing – personally as well as professionally?

Those who are familiar with me know that I don't draw a strong distinction between work and leisure. I have been able to turn my hobby into a profession - as a teacher, scientist, manager, and networker. It is and always has been important to me to enable people in my field to take on responsibility and grow as a result. I am very proud of the fact that many of my former students and doctoral candidates are now working as managers in business or as professors in academia. I see it as my task to establish a culture that is both appreciative, but also characterized by dedication and hard work - it's all about the people."

Read the second part of the interview here. Find out why it can be worth it to continue pursuing areas of research outside of the “mainstream”, if there is a right time for starting a business, and what the mid-19^th century California Gold Rush has to do with quantum technologies.