US physicist, who with German physicist Theodor W Hänsch and US physicist John L Hall shared the Nobel Prize in Physics in 2005 for his contributions to the development of laser-based precision spectroscopy. Precision spectroscopy has been used in a diverse range of applications such as the development of a new generation of highly accurate clocks and improvements to global positioning system (GPS) technology.
The nature of light can be explained in two ways. It was described by Scottish physicist James Maxwell in the 1850s as being composed of waves of electromagnetic radiation. In 1905 German-born US physicist Albert Einstein showed that light could also be described as packets of energy, known as quanta. Glauber was able to explain the nature of light in terms of quantum physics and was able to show that classical optical coherence could be described using quantum field theory. Glauber published his pioneering work on optical coherence in 1963. This discovery effectively linked classical optics with quantum physics and set the basis for the scientific field known as quantum optics. His discovery provided the theoretical basis that allowed the development of laser-based precision spectroscopy.
Glauber was born in New York City. In 1946 he was awarded a Bachelor of Science degree in physics from Harvard University, Cambridge, Massachusetts, and was awarded his PhD in physics at the same institution in 1949. In 1976 he became Mallinckrodt Professor of Physics at Harvard University and was elected a member of the National Academy of Sciences in 1988.