Engineering steady-state entanglement for two atoms held in separate cavities through laser cooling

We propose a scheme to prepare the steady-state entanglement for two atoms, which are held in separate cavities that are coupled through a short optical fiber or optical resonator. The entangled steady-state with a high fidelity can be achieved even with a low cooperativity parameter, by making use of the driving laser fields. Such a cooling mechanism is based on a resonant laser pump of the unwanted ground states to the excited states, which finally decay to the desired steady-state.

Efficient loading of ultracold sodium atoms in an optical dipole trap from a high power fiber laser

We report on a research of the loading of ultracold sodium atoms in an optical dipole trap,generated by two beams from a high power fiber laser.The effects of optical trap light power on atomic number,temperature and phase space density are experimentally investigated.A simple theory is proposed and it is in good accordance with the experimental results of the loaded atomic numbers.In a general estimation,an optimal value for each beam with a power of 9 W from the fiber laser is achieved.Our results provide a further understanding of the loading process of optical dipole trap and laid the foundation for generation of a sodium Bose–Einstein condensation with an optical dipole trap.

-50~50℃超宽温运行千瓦级光纤激光器

当前,光纤激光器工作温度范围一般较窄,如果能够扩展激光器的工作温度范围,则有望在更多的环境和领域得到应用。近期,国防科技大学基于风冷结构的光纤耦合半导体激光器(LD)泵浦的全光纤振荡器方案,在-50~50℃超宽温范围内实现了1 kW量级的激光输出。通过优化系统设计,有望进一步提升宽温运行激光器的输出功率。

原子激光陀螺

介绍了玻色-爱因斯坦凝聚态的形成机制,阐述了利用激光冷却技术制造原子激光的原理,重点介绍了原子激光陀螺的工作原理,并解释了原子激光陀螺相对于激光陀螺和光纤陀螺的1010倍的理论灵敏度。最后介绍了国外研究原子激光陀螺的现状,以及还处于实验室阶段的原子激光陀螺样品。

一种循环水冷却系统及焊接头保护气装置的应用

激光焊接技术是采用偏光镜反射激光产生的光束使其集中在聚焦装置中产生巨大能量的光束对工件进行加工的一种手段。当工件处于激光焦点附近时,就会在几毫秒内熔化和蒸发。目前在激光焊接领域中使用的激光器主要分为两类,一类是气体激光器,另一类是光纤激光器。本设计主要是利用循环水冷却来避免光纤激光器在连续焊接过程中产生的高温对同轴保护气装置构件的破坏,从而实现更高效的工作。

超冷原子冷却用集成全光纤1064 nm激光系统的研制

深度冷却是超冷原子制备过程的关键步骤,是探寻极低温度的关键技术。详细阐述了一种用于87Rb原子深度冷却的集成化全光纤1064 nm激光系统的研制方案。激光器采用两级主振荡功率放大的方案,将单一种子源信号进行放大、分束和调控,输出4路具备独立控制的激光,作为制备超冷量子气体的交叉光阱的光源。经测试,激光器在功率、稳定性、噪声等各方面满足原子深度冷却的实验需求。在地面条件下进行的两级深度冷却预实验中,获得了10 nK以下的初步实验结果,这验证了激光器具备实现超冷原子深度冷却所需的全部功能。激光器集成了种子源、放大器和全功能光学平台的功能,其内部模块采用全光纤器件研制,具有集成化、数字化、高稳定、免调试、易维护等优点,经过简易改造能够应用于远程遥控和遥测的超冷原子项目中。