“His vision of controlling chemical reactions with light pulses is now reality”
Theodor Hänsch remembers Karl-Ludwig Kompa, founding director and pioneer of laser chemistry
Karl-Ludwig Kompa, one of the founding directors of the Max Planck Institute of Quantum Optics and an internationally recognised pioneer in laser chemistry, passed away on 23 November 2025. His work helped establish the institute’s global reputation and forged a bridge between chemistry and quantum physics. Director Theodor Hänsch, who worked closely with Kompa for two decades, remembers him as a valued colleague and trusted companion.
The news of his passing has left me deeply saddened. I first met Karl Kompa before our institute was founded, and even then he impressed me as an internationally recognised expert in chemical lasers – devices in which laser energy is generated not electrically or through optical pumping, but via a chemical reaction.
Together with Siegbert Witkowsky, he led a laser project group at the Max Planck Institute for Plasma Physics, tasked with developing a large photochemical iodine gas laser for nuclear fusion. When it became clear that the pulse energy of the Asterix iodine laser would not suffice to ignite a fusion reaction, the project group was spun out of the institute. With strong support from Herbert Walther, the then newly appointed third founding director, this initiative led to the creation of the Max Planck Institute of Quantum Optics in 1981.
When I was appointed fourth director and head of the Laser Spectroscopy division at the MPQ in 1986, the institute building had just been completed. In those early years, I quickly came to appreciate Karl Kompa, head of the Laser Chemistry department, as an exceptionally kind, thoughtful, and constructive colleague. He had the rare ability to ease tensions – often just a knowing smile while calmly tending his pipe would suffice. I was also fortunate to enjoy the warm hospitality of his family and to admire his extraordinary hi-fi system.
Karl Kompa had the visionary idea of using carefully tailored short laser pulses to initiate and control chemical reactions, enabling the creation of molecules that could not be synthesised by conventional means. At the time, however, the nanosecond pulses available were far longer than the coherence times of most molecular resonances, so irradiating molecules with laser light was scarcely different from heating them with a Bunsen burner. Today, with picosecond and femtosecond lasers, Kompa’s vision has been realised: molecules now enter a new realm of quantum physics as multi-particle quantum systems.
Through his work, Karl Kompa shaped a field that bridges chemistry and quantum physics. As a professor at LMU and director at MPQ, he mentored generations of students and early-career researchers – in Munich and far beyond.
We will remember him with gratitude and deep respect.
Karl-Ludwig Kompa in pictures
