主动光钟研究进展

自2005年至今,主动光钟经过了近20年的发展。主动光钟利用原子系综作为增益介质,其受激辐射可直接作为钟激光信号。因为主动光钟工作在坏腔区域,因此具有腔牵引抑制和窄线宽两个显著的优点,可以有效克服被动光钟存在的腔长热噪声问题。由于其优越的性能,主动光钟受到了国内外同行的广泛关注。根据实现方式不同,本文将主动光钟划分为原子束型主动光钟、基于激光冷却和光晶格囚禁的主动光钟、原子束及光晶格“复合型”主动光钟、法拉第主动光钟、离子阱囚禁型主动光钟以及热原子气室型主动光钟。对于不同类型的主动光钟,本文详细介绍了其实验及理论研究进展,并分析其优劣。最后,分析了主动光钟在精密测量领域的应用并展望了主动光钟的发展方向,为推动主动光钟的广泛应用提供借鉴。

Research progress of active optical clock

Since 2005, active optical clock (AOC) has undergone nearly 20 years of development. The AOC utilizes an atomic ensemble as the gain medium, and its stimulated radiation can be used as the clock laser signal directly. Because the AOC works in the bad?cavity region, it has two significant advantages of cavity?pulling suppression and narrow linewidth, which can effectively overcome the cavity length thermal noise problem of the passive optical clock. Due to its superior performance, the AOC has received wide attention from international counterparts. According to the different implementation methods, this paper classifies AOCs into atomic beam type, laser cooling and optical?lattice?trap type, atomic beam and optical lattice "hybrid" type, Faraday atomic filter type, ion?trap type, and thermal atomic cell type. For different types of AOCs, this paper presents the experimental and theoretical research progress in detail and analyzes their advantages and disadvantages. Finally, the application of AOCs in the field of precision measurement is analyzed, and the future development direction of AOCs is prospected, so as to provide reference for promoting the wide application of AOCs.