Theodor Hänsch

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Theodor Hänsch in October 2006

Theodor Wolfgang Hänsch (born October 30, 1941 in Heidelberg ) is a German physicist and university professor . He is director at the Max Planck Institute for Quantum Optics in Garching near Munich . He is considered one of the pioneers of laser spectroscopy . Together with John Lewis Hall and Roy J. Glauber (both USA ) he was awarded the Nobel Prize in Physics in December 2005 .

Life

Hänsch 1969 was Ruprecht-Karls-University of Heidelberg with Peter Toschek after successfully defending his thesis two to interact laser light fields with excited neon atoms with the distinction summa cum laude doctorate . He then went to Arthur L. Schawlow at Stanford University , California , with a DAAD - NATO scholarship . Hänsch met Schawlow, who received the Nobel Prize in 1981 for his contribution to the development of laser spectroscopy, during a summer school in Scotland. During his time as a postdoc , Hänsch researched various questions in laser physics with Schawlow. Both were named "California Scientist of the Year" in 1973 for their work. In the same year he became a Sloan Research Fellow . Two years later, Hänsch was given his own professorship at Stanford. Among his students is Carl Edwin Wieman , who received his doctorate from Stanford in 1977 and was awarded the Nobel Prize in Physics in 2001. One of his most famous listeners is likely to have been Steve Jobs , co-founder and long-time director of Apple . In 1986 Hänsch became director and scientific member of the Max Planck Institute for Quantum Optics and professor at the Ludwig Maximilians University in Munich.

He has been a member of the American Academy of Arts and Sciences since 1983, a full member of the Bavarian Academy of Sciences since 1991 , the National Academy of Sciences since 2001 , a member of the mathematical and natural science class of the Berlin-Brandenburg Academy of Sciences since 2005 and a member since 2008 of the order Pour le Mérite for science and the arts in Berlin.

Act

Theodor Hänsch - also known as "Ted Hänsch" for short by his international colleagues since his stay in the USA - has been active in the then new research branch of experimental laser physics and quantum optics since the beginning of his scientific career and has played a decisive role in the development of this field. One of his most important creations is the frequency comb , a device that uses an interference method to measure the frequency of light waves very precisely . Hänsch's invention revolutionized metrology and opened up new areas of research in a very short time . To implement the invention in a ready-to-use commercial measuring device, the company Menlo Systems GmbH , Planegg near Munich, was brought into being, and Hänsch was involved in the establishment of this company. It is currently the world's only commercial provider of optical frequency combs. In 2005, Hänsch received the Nobel Prize for developing the frequency comb in conjunction with his other achievements in laser spectroscopy.

In June 2011, the European Research Council granted Hänsch funding of EUR 2.39 million over a period of five years. Together with his team, Hänsch will deepen his work on the frequency comb at the Ludwig Maximilians University in Munich .

Hänsch was also a co-inventor of the process of laser cooling , a method with which atoms can be cooled down to almost absolute zero by irradiating them with laser light . This procedure is essential for experiments with Bose-Einstein condensates . He also developed the first continuously tunable monochromatic dye laser . With these developments, among other things, the basis for the high-precision measurement of the Rydberg constant , the charge radii of protons and neutrons and other important atomic quantities were created.

His diverse contributions to high-resolution laser spectroscopy , in particular to Doppler-free laser spectroscopy, are now recognized and widely used as standard methods.

Laser spectroscopic measurements of his group in 2010 on muonic hydrogen led to deviations of around 4 percent for the proton radius compared to the standard value (riddle of the proton radius). This was confirmed by his group on common hydrogen in 2017.

retirement

Theodor Hänsch was honored with the Nobel Prize at the age of 64, just one year before the pension limit in Germany - according to the applicable legal regulations, he would therefore have retired in Germany on October 30, 2006. Due to this circumstance, compulsory retirement for scientists was discussed: In order to be able to continue active research, Hänsch would have had to go abroad - like many other scientists before. On July 21, 2006, a special regulation became known for Hänsch, according to which the Free State of Bavaria, the Carl Friedrich von Siemens Foundation and the Ludwig Maximilians University ensure the necessary financial and personnel resources even after his retirement. Further work at the Max Planck Institute for Quantum Optics is financed by the Max Planck Funding Foundation.

Hänsch has submitted 40 patents in the course of his life.

Awards

Hänsch received honorary doctorates from the Free University of Berlin (2006), the University of St Andrews (2006) and the Bar Ilan University (2008).

In 2006 he became a member of the Pontifical Academy of Sciences , the German Academy of Sciences Leopoldina and the Académie des Sciences , Paris.

Also in 2006 he became an honorary citizen of the cities of Garching near Munich and Florence .

Web links

Commons : Theodor Hänsch  - Collection of images, videos and audio files

Individual evidence

  1. ↑ Press portal Europa on site: German Nobel Prize winner receives 2.39 million euros from the European Research Council ( Memento from July 12, 2012 in the web archive archive.today )
  2. ^ Hänsch Group , Shrinking the proton again, 2017
  3. ↑ Beyer, Hänsch et al. a., The Rydberg constant and proton size from atomic hydrogen, Science, Volume 358, 2017, p. 79
  4. ^ Theodor Hänsch , accessed on March 24, 2020 in Wilhelmexner.org
  5. ↑ Patents by Inventor Theodor W. Hänsch , accessed on March 24, 2020 at Patents.justia.com
  6. ↑ Max Planck Institute for Quantum Optics: Bar-Ilan University in Israel awards honorary doctorate to Prof. Theodor W. Hänsch, press release from June 3, 2008. ( Memento from January 10, 2014 in the Internet Archive )
  7. ↑ Max Planck Institute for Quantum Optics: Prof. Theodor W. Hänsch becomes a member of the "Orden Pour le mérite", press release of July 31, 2008. ( Memento of January 10, 2014 in the Internet Archive )
personal data
SURNAME Hänsch, Theodor
ALTERNATIVE NAMES Hänsch, Theodor Wolfgang; Hänsch, Ted
BRIEF DESCRIPTION German physicist and Nobel Prize winner
DATE OF BIRTH October 30, 1941
PLACE OF BIRTH Heidelberg