21st Century - Physics

Ursula Keller

Ursula Keller (born 21 June 1959) is a Swiss physicist. She has been a physics professor at the ETH Zurich, Switzerland since 2003 with a speciality in ultra-fast laser technology, an inventor and the winner of the 2018 European Inventor Award by the European Patent Office.[1]


Ursula Keller grew up in a working-class family.[2] After graduating as a physics engineer in 1984 from the Swiss Federal Institute of Technology in Zurich, she continued her studies at Stanford University, where she obtained a master’s degree in applied physics in 1987, and then continued with a doctorate in physics obtained in 1989. The topic of her studies was the development of a new technique for optical measurement of charge and voltage in GaAs type integrated circuits.

From 1989 to 1993, she worked at AT&T Bell’s research centre in New Jersey, where she conducted research on photonic switching, ultra-fast laser technology and semiconductor spectroscopy and developed a method for manufacturing ultra-short pulse lasers.

In 1993, she was appointed Professor of Physics at the Swiss Federal Institute of Technology in Zurich, becoming the school’s first female Professor of Physics.[3] In October 1997, she became a full professor.

Her research areas are ultra-fast solid-state and semiconductor lasers, the development of reliable and functional instruments to generate extreme ultraviolet (EUV) X-rays and attosecond science. She developed the first method for generating ultra-fast light pulses known as semiconductor saturable-absorber mirrors (SESAMs), which have become a worldwide industry standard for cutting and welding in fields ranging from electronics and automotive industry to communications technology, medical diagnostics and surgery and has made myriad important contributions to the field of laser science since.[4] Dr. Keller’s earlier research into carrier envelope phase stabilization and frequency comb technology was integral to Theodor W. Hänsch and John L. Hall’s development of laser-based spectroscopy that garnered them the 2005 Nobel Prize in Physics.[5]

Ursula Keller has nearly 700 articles published with total citation of 45131 and h-index of 109.[6] Her most popular publication[7] has cited by 1905 people (as on 12th September 2020).[6]

Ursula Keller is the founder and president of ETH Women Professors Forum[8]

Ursula Keller has patented several inventions in the field of ultra-fast lasers for industrial and medical applications.[9]

She is the creator of the Attoclock, one of the most accurate time measurement devices in the world, which can record time intervals up to a few attoseconds, the billionth part of a billionth of a second.[10]

Since 2010, Ursula Keller has been Director of the Swiss National Research Centre for Ultra-fast Molecular Sciences and Technologies.

Since 2014, she has been a member of the Research Council of the Swiss National Science Foundation.[10]

In 2018, Ursula Keller won the European Inventor Award in the “Lifetime Achievement “.[9] In 2019, she was appointed as one of the leading experts that judges proposals for this award.[11]

She won the IEEE Photonics Award[12] in 2018 and the IEEE Edison Medal[13] in 2019.

She won the 2020 Gold Medal from the Society of Photo-Optical Instrumentation Engineers[14] and the 2020 Frederic Ives Medal / Jarus Quinn Prize[15] from the Optical Society.


In March 2019, in the context of the mobbing allegations against Marcella Carollo, Ursula Keller denounced a “lack of leadership, gender discrimination and corruption at ETH Zurich” and claimed that the reason for the proposed dismissal of her colleague was “not primarily the mobbing allegations, but her gender”.[16] Female colleagues strongly disagreed with this statement in an open letter to the leadership of ETH. In the same period, Ursula Keller has been formally reprimanded by ETH Zurich, including the mention of a possible dismissal in case of recurrence.[17] Two external investigations disproved the accusations that Ursula Keller made against ETH Zurich.[18] During these investigations, Ursula Keller retracted her allegations of corruption and abuse of office.[19] Otherwise, the Swiss Federal Audit Office recommended more transparency in the distribution of funds[2]

Awards and honors

  • Joseph Fraunhofer Award / Robert M. Burley Prize from The Optical Society, 2008 “For seminal contributions to the development and application of ultrafast lasers and notably pioneering work on semiconductor saturable absorber mode-locking.”[20]
  • Fellow of the Institute of Electrical and Electronics Engineers (IEEE), 2014[21] for contributions to ultrashort pulse mode locked laser physics and technology
  • Charles Hard Townes Award from The Optical Society “For seminal contributions in the fields of octave-spanning lasers, frequency comb technology, and high repetition-rate ultrafast semiconductor disc lasers.”[22]
  • Weizmann Women and Science Award in 2017[23]
  • European Inventor Award 2018 for laser technology in the category “Lifetime achievement.”[24][9]
  • IEEE Photonics Award,[12] 2018
  • IEEE Edison Medal,[13] 2019
  • SPIE Gold Medal, 2020[25]
  • Frederick Ives Medal/Quinn Prize from The Optical Society in recognition of her work in ultra-fast laser technology[26]
  • Elected to the National Academy of Sciences in 2021[27]


  1. ^ “Optoelectronics Interview with Dr. Ursula Keller”. 2008-09-06. Archived from the original on 2008-09-06. Retrieved 2020-05-10.
  2. Jump up to:a b “Die Tragik der ersten Physik-Professorin”Limmattaler Zeitung. 2022-07-23. Retrieved 2022-08-05.
  3. ^ Logean, Sylvie (2018-04-25). “Ursula Keller a vu la lumière au bout du laser”Le Temps (in French).
  4. ^ “The Group”ulp.ethz.ch. Retrieved 2019-10-23.
  5. ^ “Ursula Keller – Engineering and Technology History Wiki”ethw.org. Retrieved 2019-10-23.
  6. Jump up to:a b “Ursula Keller – Google Scholar”scholar.google.com.au. Retrieved 2020-09-12.
  7. ^ Keller, U.; Weingarten, K.J.; Kartner, F.X.; Kopf, D.; Braun, B.; Jung, I.D.; Fluck, R.; Honninger, C.; Matuschek, N.; Aus der Au, J. (September 1996). “Semiconductor saturable absorber mirrors (SESAM’s) for femtosecond to nanosecond pulse generation in solid-state lasers”IEEE Journal of Selected Topics in Quantum Electronics2 (3): 435–453. Bibcode:1996IJSTQ…2..435Kdoi:10.1109/2944.571743ISSN 1558-4542.
  8. ^ “Prof. Dr. Ursula Keller | Women In Science”www.weizmann.ac.il. 25 April 2017. Retrieved 2018-12-14.
  9. Jump up to:a b c “Swiss physicist wins European Inventor Award for laser technology”SWI swissinfo.ch. Retrieved 2018-06-08.
  10. Jump up to:a b Echos, Les (2018-05-03). “Des impulsions laser ultrarapides pour l’industrie et la médecine”lesechos.fr (in French).
  11. ^ Office, European Patent. “European Inventor Award: jury members”www.epo.org. Retrieved 2019-01-21.
  12. Jump up to:a b “IEEE Photonics Award Recipients”www.ieee.org. Retrieved 2020-05-10.
  13. Jump up to:a b “IEEE Edison Medal Recipients”www.ieee.org. Retrieved 2020-05-10.
  14. ^ “Gold Medal Winner Ursula Keller Among SPIE Award Honorees”www.photonics.com. Retrieved 2020-05-10.
  15. ^ “OSA Honors Ursula Keller with Highest Award”www.photonics.com. Retrieved 2020-05-10.
  16. ^ Aeschlimann, Silvan; Bühler, Dennis; Osswald, Dominik (22 March 2019). “Interview of Ursula Keller with the Online Platform “Republik””Republik. Retrieved 2020-05-10.
  17. ^ “NZZ am Sonntag, May 11, 2019”. Retrieved 2020-05-10.
  18. ^ “Tagesanzeiger, July 11, 2019”. Retrieved 2020-05-10.
  19. ^ “Report on the administrative investigation at the physics department D-PHYS of ETH Zurich” (PDF). Retrieved 2020-05-10.
  20. ^ “Joseph Fraunhofer Award / Robert M. Burley Prize”The Optical Society.
  21. ^ “2014 elevated fellow”IEEE Fellows Directory.
  22. ^ “Charles Townes Award”The Optical Society.
  23. ^ “Ursula Keller receives Weizmann Women & Science Award”www.phys.ethz.ch. 2017-06-07. Retrieved 2018-12-14.
  24. ^ Six award winning inventors changing the world. Euronews, 7 June 2018. Retrieved 7 June 2018.
  25. ^ “Ursula Keller: The 2020 SPIE Gold Medal”SPIE. November 13, 2019. Retrieved November 26, 2019.
  26. ^ “Frederic Ives Medal / Jarus W. Quinn Prize”The Optical Society. Retrieved 10 May 2020.
  27. ^ “2021 NAS Election”www.nasonline.org. Retrieved 2021-05-17.

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