Bürkert University Prize for IFSW’s Yassin Nasr

“Development of an optical system for the high-precision and fast movement of laser beams for laser micromachining with lenses of high numerical aperture.” So reads the title of Yassin Nasr’s Mechanical Engineering Master’s thesis. Picked for this year’s best master’s thesis by IFSW’s former doctoral candidates (VEDIS), Yassin has now received further recognition on a university level. The doctoral candidate from the Institute für Strahlwerkzeuge (IFSW) was awarded a Bürkert University Prize for a final thesis at the University’s annual celebration on November 28, 2025.

Focusing laser beams with the highest precision (in the µm range), shaping them dynamically, and moving them at high speed – in one complete system? Yassin’s work provides an answer that covers the entire range: from system design and experimental validation, to system integration.

The goal of the thesis was the development of an optical system which combines:

1. A scanner for fast movement of the laser beam
2. A beam shaping system for the dynamic change of the intensity distribution
3. A microscope objective to achieve a µm focal spot

Yassin’s highly innovative approach integrates a spatial light modulator (SLM) for beam shaping, a scanner for beam movement, and a microscope objective with a high numerical aperture (NA = 0.4).

Now he’s working on integrating the optical system of his master’s thesis into a complete laser micromachining platform equipped with an ultrafast laser and a high precision axis system. This system will be used to investigate laser micromachining processes – such as direct laser writing to create integrated waveguides in glass, laser-assisted etching to realize 3D-geometries such as lenses inside a bulk material, and laser bonding of glass. Together, these processes form the technological basis to fabricate photonic integrated circuits within a single laser-based manufacturing system.

Atomic vapor-cell sensors for magnetometry, frequency standards, or gyroscopes – there are many exciting potential uses for quantum sensors. One obstacle to bringing such quantum sensors into application is the size and complexity of the laboratory setup necessary to perform highly accurate measurements. The miniaturization of these setups is crucial to overcome this limitation. By combining scalable laser-based micromachining processes, it becomes possible to fabricate photonic integrated circuits – an enabling technology for compact, stable, and application-ready quantum sensors.

Potential uses in medical devices could be a gamechanger. Miniaturization would make it easier to measure magnetic fields in muscles and the tiny currents that induce muscle movements. In this way, clinicians could determine which muscle is working, and for example then duplicate this on a robotic arm. Measuring and evaluating brain activity could help stroke patients relearn movements. These applications rely on an accurate measurement of very small magnetic fields with a small device.

Aside from the many staff members who contributed along the way, Yassin would especially like to thank Alexander Peter, Patrick Hildebrand, and Tobias Menold from the Systems Engineering department for their supervision and support throughout the completion of his master’s thesis. Furthermore, he thanks Professor Michalowski for nominating him for the Bürkert University Prize.

“IFSW has people in the Systems Engineering department who have broad expertise in developing complex optical setups and controlling them. There are people who are doing laser development with a deep knowledge of laser design and the handling of highly sensitive optical systems. And the Process Fundamentals department has people working with the machines who are experts in the experimental investigation of laser manufacturing processes.”

Yassin says he really profited from all this pooled expertise while completing his thesis. People from different departments are extremely helpful with their insights and research topics, supporting the students in investigating challenging topics. “The successful development of the optical system was only possible because of the organizational structure and technical infrastructure of the institute. Access to the well-equipped IFSW inventory was essential for combining several high-value components into a single optical setup. It wouldn’t be possible to build it all from scratch – it’d be too expensive. The inventory is a huge advantage.”

While forming a vision for a longer timescale, Yassin is keeping his feet on the ground, making the first steps at the institute and building expertise in this case. He’d like to see how a particular application could develop, rather than just stay with the fundamentals. In general, he’s passionate about seeing expertise in photonics and lasers further develop in the region and for Germany. Optics and measurements are crucial in space research too. Perfecting this technological infrastructure will allow diverse applications and Yassin hopes to see such “futuristic” topics being broadly researched in the coming years.

To find out more, contact IFSW or Yassin.