Subject：The crisis and hope on glass-cell based secondary optical frequency standard

Speaker：Wang-Yau Cheng, Associate Professor, Department of Physics, National Central University

Time：10:00am,13th July,2016

Place：lecture hall,3F, Pinbiao Building of Institute，WIPM

Abstract: 

Optical frequency standards based on Rubidium and Cesium atom two-photon transitions are long recognized as reliable secondary optical clocks within 10-kHz reproducibility. We found that the cesium atom from different sources (including that from Max Planck Institute, T. Hansch’s group), have significant discrepancies from that in Taiwan in terms of some spectral features, which surprised and puzzled scientists (see: Spotlight on Optics by Optical Society of America: http://www.opticsinfobase.org/spotlight/summary.cfm?URI=ol-38-16-3186). Recently, we had observed some strong evidences that might reveal the truth for what happened to cesium atoms in glass cells. We will present our experimental data in this talk.