Theodor Hänsch

Born on 30 October 1941 in Heidelberg, Germany, Nobel-winning atomic physicist Theodor Hänsch is a pioneer of ultraprecise laser spectroscopy. He studied physics at the University of Heidelberg, earning his MS in 1966 and PhD in 1969. In 1970, Hänsch went to the US as a NATO postdoc to work with Arthur Schawlow, coinventor of the laser, at Stanford University. He later joined the Stanford faculty, becoming associate professor of physics in 1973 and full professor in 1975. His research in the 1970s and early 1980s centered on building a monochromatic tunable dye laser and developing various spectroscopy techniques. In 1986 he returned to Germany, where he accepted a professorship at the University of Munich and set up a new laser spectroscopy lab at the Max Planck Institute for Quantum Optics. In the late 1990s, Hänsch developed the optical frequency comb in mode-locked lasers. The technique has found a number of applications, including the improvement of satellite-based navigation systems, synchronization of computer data networks, and testing of the fundamental physical constants. For his work on laser-based precision spectroscopy, Hänsch received the 2005 Nobel Prize in Physics . Also in the 1990s Hänsch began to focus on the physics of ultracold atoms. In addition to the Nobel, he has received a number of other awards, including the 1995 Einstein Prize for Laser Science, the 1996 Arthur L. Schawlow Prize in Laser Science, the 2001 Matteucci Medal, the 2005 Frederic Ives Medal, and the 2005 I. I. Rabi Award. (Photo credit: AIP Emilio Segrè Visual Archives, Physics Today Collection)

Date in History: 30 October 1941