Tuesday, October 4 2005 19:26 Hrs (IST) - World Time -

Stockholm: Americans John L. Hall and Roy J. Glauber and German Theodor W. Haensch have won the 2005 Nobel Prize in physics.

Hall and Haensch won 'for their contributions to the development of laser-based precision spectroscopy, including the optical frequency comb technique' while Glauber won for his contribution to the quantum theory of optical coherence.

"This year's Nobel Prize in physics is awarded to three scientists in the field of optics. Roy Glauber is awarded half of the Prize for his theoretical description of the behaviour of light particles. John Hall and Theodor Haensch share the other half of the Prize for their development of laser-based precision spectroscopy, that is, the determination of the colour of the light of atoms and molecules with extreme precision," the assembly said in its citation.

"The important contributions by John Hall and Theodor Haensch have made it possible to measure frequencies with an accuracy of 15 digits," the assembly added.

"Lasers with extremely sharp colors can now be constructed and with the frequency comb technique precise readings can be made of light of all colors," he said.

"This technique makes it possible to carry out studies of, for example, the stability of the constants of nature over time and to develop extremely accurate clocks and improved GPS technology.