Laser Cooling Alkaline-earth Atoms for Optical Clock in Chinese Space Station
Abstract This study presents an achievement of laser cooling of alkaline-earth atoms in the Chinese Space Station’s strontium (Sr) atomic space optical clock. The system’s core components, physical unit, optical unit, and electrical unit, have a total volume of 306 L and a total mass of 163.8 kg. These compact and robust units can overcome mechanical vibrations and temperature fluctuations during space launch. The laser sources of the optical unit are composed of diode lasers, and the injection locking of slave lasers is automatically performed by a program. In the experiment, a blue magneto-optical trap of cold atoms was achieved, with the atom numbers estimated to be approximately (1.50 ± 0.13) × 10 6 for 87 Sr and (8.00 ± 0.56) × 10 6 for 88 Sr. This work establishes a foundation for atomic confinement and high-precision interrogation in space-based optical clocks and expands the frontiers of cold atom physics in microgravity.
Authors
- Hongxin Zou (ORCID: https://orcid.org/0000-0002-4172-5214)
- Feng Guo (ORCID: https://orcid.org/0000-0002-7468-5634)
- Junwei Meng (ORCID: https://orcid.org/0000-0002-1606-7088)
- Dejing He
- Guodong Zhao (ORCID: https://orcid.org/0000-0002-9920-8244)
- Wenhai Wang (ORCID: https://orcid.org/0000-0003-3707-6546)
- Xiaotong Lu (ORCID: https://orcid.org/0000-0002-5395-9384)
- Yongzhuang Zhou (ORCID: https://orcid.org/0000-0002-4296-0726)
- Benquan Lu (ORCID: https://orcid.org/0000-0002-3371-0573)
- Feng Gao (ORCID: https://orcid.org/0000-0001-8617-2484)
- Tan Wei (ORCID: https://orcid.org/0000-0002-1877-2979)
- Yun Liu (ORCID: https://orcid.org/0000-0002-8536-9143)
- Min Feng
- Jian Xia (ORCID: https://orcid.org/0000-0002-2065-0487)
- Jie Ren (ORCID: https://orcid.org/0000-0001-8299-945X)
- Yong Shen
- Xiang-Ping Hu
- Chihua Zhou (ORCID: https://orcid.org/0000-0002-3113-1367)
- Hong Chang
- Yebing Wang
- Ting Liang
- Qinfang Xu Qinfang Xu
Institutions
- National University of Defense Technology (CN)
- Chinese Academy of Sciences (CN)
- National Time Service Center (CN)
- Aerospace Information Research Institute (CN)
- University of Chinese Academy of Sciences (CN)
Publication Details
- Journal
- Chinese Physics Letters
- Published
- 2025-04-22
- DOI
- https://doi.org/10.1088/0256-307x/42/6/063701
- Citations
- 5
- Primary Topic
- Advanced Frequency and Time Standards
- Type
- article
- Field-Weighted Citation Impact
- 6.23