High performance of semiconductor optical amplifier available for cold atom physics research

We present a novel design of a compact, stable, and easy-adjustable semiconductor optical amplifier （SOA） system. This SOA system is capable of providing up to 560-roW laser power at the wavelength of 852 nm. For the continuous-wave （CW） seeding laser, the amplification gain can reach 18 dB. We add amplitude modulation onto the CW laser and measure the modulation amplification between seeding and output laser. The amplification gain remains constant within the frequency range from 10 Hz to 1 MHz. The whole system could work in ultra-stable condition： for CW seeding laser, the fluctuation of output power is less than 0.33% in several hours.     

超冷极性分子

目前对超冷原子的研究已经从最初的原子分子物理扩展到了物理的很多分支.极性分子可以将电偶极相互作用引入到超冷体系,同时分子又与原子类似,可以灵活地被光和其他电磁场操控,因而很多理论工作都预言了超冷极性分子在超冷化学、量子模拟和量子信息等领域会有重要的应用.但由于超冷基态分子的制备非常困难,如何把超冷物理从原子发展到分子还是一个方兴未艾的课题.过去的10年间,各种分子冷却技术都取得了很大突破,本文回顾了这些进展,并着重介绍了基于异核冷原子的磁缔合结合受激拉曼转移这一技术,该技术在制备高密度的基态碱金属超冷极性分子上取得了较大的成功.本文也总结了超冷极性碱金属分子基本碰撞特性研究的一些实验结果.     

超冷原子系综的非高斯纠缠态与精密测量

量子精密测量是基于量子力学的基本原理对特定物理量实施测量,并利用量子效应提高测量精度的交叉科学.随着超冷原子实验技术的发展,超冷原子为量子精密测量提供了一个优异的研究平台.利用发展成熟的量子调控技术,人们可以基于超冷原子系综制备一些新奇的非高斯多粒子纠缠态.基于多体量子干涉,利用这些非高斯纠缠态作为输入,可以实现超越标准量子极限的高精度测量.本文简要综述这一研究领域的进展.     

High-performance laser power feedback control system for cold atom physics

A laser power feedback control system that features fast response,large-scale performance,low noise,and excellent stability is presented. Some essential points used for optimization are described. Primary optical lattice experiments are given as examples to show the performance of this system. With these performance characteristics,the power control system is useful for applications in cold atom physics and precision measurements.