Optical molasses loaded from a slow atomic beam

CHEN Jiang^1,2, ZHANG Hui^1,3, RUAN Jun^1,4, WANG Xin-liang^1,4,

LIU Dan-dan^1,4, ZHANG Shou-gang^1,4

(1. National Time Service Center, Chinese Academy of Sciences, Xi′an 710600, China;

2. Graduate University of Chinese Academy of Sciences, Beijing 100039, China;

3. Institute of Photonics & Photon technology, Northwest University, Xi′an 710069, China;

4. Key Laboratory of Time and Frequency Primary Standard, National Time Service Center,

Chinese Academy of Sciences, Xi′an 710600, China)

Abstract: Preparation of the optical molasses is one of the key steps for developing a fountain clock. The optical molasses is loaded from a slow atomic beam, and the fluorescence collection method is applied to determine the number of atoms in the optical molasses, meanwhile the time-of-flight(TOF) method is used to measure the temperature of the optical molasses. The number of cold atoms in the optical molasses for loading time of 200 ms is determined to be (8.14±0.2)×10⁷, and the temperature of cold atoms is determined to be (10.72±0.69) μK.