Ursula Keller

Ursula Keller (born 21 June 1959) is a Swiss physicist. She has been a tenured physics professor at ETH Zurich, Switzerland since 1993. A pioneer in ultrafast science and technology, she is known for inventing the semiconductor saturable absorber mirror (SESAM), enabling passive mode-locking of lasers and revolutionizing ultrafast laser applications in science and industry. Keller led the Swiss NCCR MUST program in ultrafast science (2010–2022), co-founded several companies, including Time-Bandwidth Products and K2 Photonics, and published a graduate textbook "Ultrafast Laser Physics" with Springer Verlag. She is highly cited and received many prestigious awards. From 2012-2016 she was the founding president of the Women Professors Forum at ETH Zurich.