主要介绍了可移动锶原子光晶格钟的系统研制和钟跃迁谱线探测。光钟系统采用尺寸为120 cm×50 cm×60 cm的小型化物理系统,通过光纤将模块化的子光路系统与物理系统连接。经过一级461 nm激光和二级689 nm激光冷却后,得到原子数目为1.02×10 6、原子温度为5.45 μK的冷原子团。利用具有“魔术波长”的晶格光实现 87Sr的一维光晶格装载,晶格寿命为434 ms,晶格中原子温度为4.63 μK。在具有超窄线宽的698 nm钟激光探测下,得到边带可分辨的钟跃迁谱、窄线宽简并谱、自旋极化谱及拉比振荡曲线。经钟激光探询后,得到的自旋极化谱的谱线线宽为11.79 Hz,接近傅里叶探测极限的理论值,为可移动光钟的闭环工作提供了频率参考。

This work mainly presents the system development and clock transition spectroscopy detection of a transportable ⁸⁷Sr optical lattice clock. The optical clock system uses a miniaturized physical system with a size of 120 cm×50 cm×60 cm, which connects the modularized sub-optical system through fibers. After subsequent to cooling with a first stage 461 nm laser and a second stage 689 nm laser, a cold atomic cloud with an atomic number of 1.02×10 ⁶ and an atomic temperature of 5.45 μK is obtained. The lattice light with a magic-wavelength is used to load ⁸⁷Sr in one-dimensional optical lattice with a lifetime of 434 ms, and an atomic temperature in lattice of 4.63 μK. The atoms are detected using an ultra-narrow linewidth 698 nm clock laser to obtain the clock transition spectrum with distinguishable sidebands, the degenerate spectrum with narrow linewidth, the spin-polarized spectrum, and the Rabi-flopping curve. The spin-polarized spectrum with linewidth of 11.79 Hz is obtained under the condition of clock laser interrogating, which is fairly close to the theoretical value of Fourier limit linewidth and can be as the frequency reference for the future optical clock closed-loop.