Some inventions have the potential to affect virtually all aspects of our lives. When Ursula Keller, passionate physicist and professor, developed the semiconductor saturable absorber mirror (SESAM) in 1992, she provided scientific research, industrial micromachining and critical medical operations with a tool of unprecedented precision and revolutionised laser technology as a whole. Considering this and her career spanning more than three decades, the EPO honoured Prof Keller with the European Inventor Award 2018 in the category “lifetime achievements”.
A typical diode-pumped solid-state laser produces a continuous beam using a crystal between two mirrors. Prof Keller altered this very approach and incorporated special reflective semiconductors acting as mirrors inside the laser device. The difference is, that the semiconductor only amplifies the high-energy light, creating ultra-fast laser pulses. It was the first practical method for creating ultra-fast pulses in solid-state lasers, as well as lasers used in consumer electronics and in quantum physics research. Prof Keller has since further advanced the SESAM concept to include more types of lasers and has designed precise scientific measuring equipment that analyses fundamental physics at the quantum level.
Overall, the SESAM principle gave lasers more accurate control over material processing. It is used in nearly all commercially available ultra-fast lasers for micromachining, materials processing and medical surgery and has unlocked new processing techniques in fields ranging from optoelectronics and smartphone production to medical surgery and automotive manufacturing. "There is hardly anything that is not processed with short-pulsed lasers and the applications continue to grow," says Prof Keller. According to the EPO, ultra-fast lasers already constitute 20% of the global laser market and generated EUR 2.2 billion in 2017. Keller's invention and dedicated work has contributed to Europe taking a leading role in the field of ultra-fast laser development.
Ursula Keller has not only revolutionised laser technology, but also contributed her fair share to advance gender equality. As a global pioneer and proven expert in ultra-fast photonics, she is mentor to the next generation of laser researchers -- many of whom have become professors and start-up entrepreneurs -- and opening doors to women in science. Ursula Keller is one of four women being honoured with the 2018 European Inventor Award, the highest number since it has been launched in 2006. During the award ceremony, EPO President Benoît Battistelli stated: “I am particularly pleased to see that this year’s edition recognizes the strong contribution of women inventors in many fields traditionally dominated by men. (…) Ursula Keller has dedicated her career to research and innovations that have charted new directions in laser technology and unlocked applications in a broad range of industries such as electronics and automotive manufacturing.”
The European Inventor Award is presented annually by the EPO to distinguish outstanding inventors from Europe and around the world who have made an exceptional contribution to social development, technological progress and economic growth. The winners were chosen by an independent international jury from more than 500 individuals and teams of inventors put forward for this year's award.
(© AcademiaNet / EPO)