面向空间引力波探测的低噪声稳频激光器

基于未来卫星间激光干涉任务的需求,介绍了一种基于迈克耳孙光纤干涉仪稳频的1064 nm激光稳频系统,该系统采用全光纤器件,结构紧凑、体积小、可靠性强。通过拍频测试,得到该系统的频率噪声在30 mHz～1 Hz范围内小于30 Hz/Hz1/2,频率稳定度在积分时间为1 s和1000 s时分别为1.2×10-14和3×10-13。该系统的性能满足LISA任务对稳频激光的需求,有望应用于未来的空间引力波探测任务。     

Observation of the ~1S_0-~3P_0 optical clock transition in cold ~(199)Hg atoms

We report on the observation of the highly forbidden ~1S_0–~3P_0 optical clock transition in laser-cooled ~(199) Hg atoms.More than 95% depletion of cold ~(199)Hg atoms is detected in the magneto-optical trap. Using the free-of-field detection method, the AC Stark shift from the cooling laser is removed from the in-field spectroscopy. At low-power clock laser pumping, the linewidth of the clock spectroscopy is approximately 450 k Hz(full width at half-maximum), which corresponds to a Doppler broadening at the atom temperature of 60 μK. We determine the ~1S_0–~3P_0transition frequency to be 1,128,575,290.819(14) MHz by referencing with a hydrogen maser and measuring with a fiber optical frequency comb. Moreover, a weak Doppler-free signal is observed.     

基于红失谐高斯光束的冷原子束流长距离传输

提出了一种利用红失谐高斯光束偶极力实现二维磁光阱长距离传输冷原子束的方案.利用二能级原子所受散射力公式分析并构造了87 Rb原子在光偶极阱二维磁光阱(2D-ODT MOT)中的受力公式,考虑了原子与背景气体碰撞的影响,利用四阶龙格-库塔法求解原子运动方程,获得原子的运动轨迹,统计并求出原子在不同高斯光束失谐以及功率条件作用下进入差分泵浦范围的原子数.实验验证了在红失谐高斯光束与原子束推送光相互组合的4种工作状态下科学实验腔中磁光阱冷原子装载情况.理论与实验结果表明:基于红失谐高斯光束的二维磁光阱长距离传输冷原子束的效果提升显著,科学腔原子装载效率明显提升、原子数目明显增加.     

Vibration insensitive optical ring cavity

The mounting configuration of an optical ring cavity is optimized for vibration insensitivity by finite element analysis. A minimum response to vertical accelerations is found by simulations made for different supporting positions.