A compact cold-atom clock based on a loop-gap cavity

• Published in: Applied physics letters Vol. 119; no. 6
• Main Authors: Lee, Sangmin, Choi, Gyeong Won, Hong, Hyun-Gue, Kwon, Taeg Yong, Lee, Sang-Bum, Heo, Myoung-Sun, Park, Sang Eon
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 09-08-2021
• Subjects: Applied physics; Atomic clocks; Cold atoms; Free fall; Frequency stability; Holes; Laser cooling; Q factors
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/5.0057150

We introduce a compact atomic clock based on laser-cooled atoms trapped inside a loop-gap microwave cavity. The cavity occupies a volume eight times smaller than conventional cylindrical cavities while maintaining a high quality factor in the presence of the ten apertures required for optical manipulation of cold atoms. The measured linewidth of the Ramsey spectrum, which is limited by the free fall distance of the atomic cloud in the cavity, was 19.6 Hz. The corresponding frequency instability was σy(τ) = 2.5 × 10−12 τ−1/2, which could be further improved by reducing the local oscillator noise. This work paves a way toward high-performance portable atomic clocks.