In physics many subtle phenomena can be studied by allowing waves to interfere with each other. In an interferometer, light waves travel by two different paths, directed from place to place by strategically places mirrors, and converge at a detector, where they produce a striped interference pattern.
The pattern can be read out to learn details of the journey taken by the waves. Interferometry is used in many endeavors, such as navigation, optical clocks, encryption, and in the attempt to observe gravitational waves. The quality of the interferometer depends on the positions of the mirrors being precisely stable. Unfortunately, when experiments are carried out at room temperature the smallest amount of heat present will agitate the mirrors; a century ago Albert Einstein demonstrated the relation between fluctuations ("Brownian motion") brought about by thermal energy.
H. Jeff Kimble of Caltech will describe a new effort to counteract thermal noise and improve the sensitivity of interferometers. He and his colleagues argue that a very slight thermally-induced movement of a mirror's surface owing to thermal noise is accompanied by associated changes in other physical parameters, such as the index of refraction of the mirror. These correlated changes can be exploited to compensate, in a coordinated way, the deleterious effects of the mirror surface's motion.
This research is scheduled to be presented during the 2009 Conference on Lasers and Electro-Optics/International Quantum Electronics Conference (CLEO/IQEC) May 31 to June 5 at the Baltimore Convention Center in Baltimore.
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