Theodor W. Hänsch, physicist, won half the Nobel Prize in Physics in 2005 jointly with John L. Hall "for their contributions to the development of laser-based precision spectroscopy, including the optical frequency comb technique.” They shared the 2005 prize with Roy J. Glauber who won "for his contribution to the quantum theory of optical coherence.” Theodor Hänsch is best known for his work in precision-based laser spectroscopy. He, like John Hall, worked on frequency combs and used these to make very accurate and precise measurements of atomic lines. Atomic lines refer to the frequency of the electromagnetic energy that atoms absorb or emit as its electron(s) change energy levels.
