Topic: Atomic Clocks
Speaker: Mr. Krishna Myneni, U.S. Army RDECOM
Date & Time: Thursday, Oct. 12, 2006, 1:00 PM
Place: Room 140 VMC (Chambers Hall)
The next decade is likely to see the injection of high accuracy, high precision time and frequency sources (atomic clocks) into mobile technologies such as positioning and communications systems. An overview of atomic clock technology will be presented. Techniques for the use of atomic and molecular transitions for accurate and stable frequency references will be reviewed and compared. These include the microwave absorption cell, the atomic beam (typically Cesium) device, optical-microwave double-resonance technique, laser-cooled atom method (Cs fountain clock), and the recent chip-scale atomic clocks based on the phenomenon of coherent population trapping (CPT). The basic science behind these techniques will be discussed. We will also compare the relative frequency stability, and corresponding time uncertainty, for these methods.
Note: This year, researchers at NIST demonstrated the optical clock, a clock which tick at optical frequencies (1015 Hz), using a single trapped mercury ion. Such a clock is expected to have a time uncertainty of less than 1 sec in 400 million years (the current primary standard is based on the Cs fountain clock, which has a time uncertainty of < 1 sec in 70 million years).
Mr. Krishna Myneni is a research physicist with the U.S. Army Research Development, and Engineering Command. He holds a M.S. degree in physics (U. of Louisville, 1987), and is presently working towards his Ph.D. at Alabama A&M. Over the course of his career, Mr. Myneni has performed research and published in a variety of areas, including atomic and molecular spectroscopy, optics (linear and nonlinear), and control and applications of chaos. Most recently, Mr. Myneni's research interest is in optical manipulation of atomic states for applications in quantum information and time/frequency standards.
Refreshments will be served at 12:45 PM