Roy Glauber, 80, of Harvard University, was awarded half the 2005 honor while the other half is to be split between John Hall, 71, of the University of Colorado, and Theodor Hansch, 64, of the Max Planck Institute in Munich, Germany.
Glauber's research, in which quantum theory was applied to optics, was honored by the Nobel committee. Hall and Hansch contributed studies that allow for the increasingly accurate measurements of light frequencies, which have been used in improve global positioning technology.
"As long as humans have populated the Earth, we have been fascinated by optical phenomena and gradually unraveled the nature of light," the committee said in a release. It credited Glauber for his description of the behavior of light particles and Hall and Hansch for refining techniques to improve measurement of light frequencies.
The award will be formally presented in Stockholm, Sweden, Dec. 10 -- the anniversary of the birth of Alfred Nobel. The 2005 prizes carry a cash award of about $1.3 million.