Ten Years of Active Optical Clocks

Wednesday, April 22, 2015

12:00pm | Physics 128

Presenter

Dr. Jingbiao Chen , Institute of Quantum Electronics, and State Key Laboratory of Advanced Optical Communication System & Network, School of Electronics Engineering and Computer Science

The concept of active optical clock was proposed ten years ago. In this talk, after a simple review, we will mainly present the most recent experimental progresses of active optical clocks in Peking University, including 4-level Cesium active optical frequency standards and active Faraday optical frequency standards.

The first part focuses on the 4-level Cesium active optical clocks. When Cesium atoms within a FP cavity with a finesse of 4.3, which is at deep bad-cavity regime, are pumped by 455.5 nm and 459.3 nm laser, the stimu-lated emission radiations at 1469.9 nm from 7S1/2-6P3/2 is realized. The measured threshold, linewidth, cavity-pulling reduction, saturation effect of pumping laser, hyperfine structure effect, etc. will be discussed in detail.

The second part will focuses on active Faraday optical clocks at deep bad-cavity regime with Cesium atoms. The Faraday effect of magneto-optical rotation discovered by Michael Faraday in 1845, is applied to realize mod-ern optical clocks, which has advantages of separated quantum frequency reference and gain medium. Measured by the optical heterodyne beat between two similar independent active Faraday optical frequency standards, re-sults show the frequency linewidth reaches 281(23) Hz, which is 19000 times smaller than the natural linewidth of the Cesium 852 nm transition line