Theodor W. Hänsch
The Nobel Prize in Physics 2005
Born: 30 October 1941, Heidelberg, Germany
Affiliation at the time of the award: Max-Planck-Institut für Quantenoptik, Garching, Germany, Ludwig-Maximilians- Universität, Munich, Germany
Prize motivation: "for their contributions to the development of laser-based precision spectroscopy, including the optical frequency comb technique."
Prize share: 1/4
According to quantum physics, light and other electromagnetic radiation appear in the form of quanta, packets with fixed energies, which also correspond to energy transitions in atoms. Consequently, determining the frequency of light waves provides information about the atoms' properties, benchmarks for time and length, and the possibility of determining physical constants. Around the year 2000, Theodor Hänsch and John Hall developed the frequency comb technique, in which laser light with a series of equidistant frequencies is used to measure frequencies with great precision.
Their work and discoveries range from how cells adapt to changes in levels of oxygen to our ability to fight global poverty.
See them all presented here.