Physics Seminar
Dr. Roger Brown
National Institute of Standards and Technology

Abstract: I will present an overview of optical lattice clocks. These clocks offer the near term prospect of surpassing the current SI definition of the second by a factor of 100. In particular, we will discuss the primary factors that contribute to clock instability. By simultaneously interrogating two independent atomic systems with the same clock laser, we reject a number of noise sources, and observe unprecedented oscillator stability. Such stability opens up the possibility of measuring gravitational red-shifts arising from ocean tides. In addition to stability, clock performance is also characterized by accuracy. We describe our experimental efforts to characterize systematic frequency shifts including: the temperature of the system, and stray electromagnetic fields.

** Refreshments will be served, as well. **