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.     

High sensitive detection of high-order partial wave scattering in photoassociation of ultralcold atoms

We report on the observation of enhanced high-order partial wave scattering from atom–atom interaction via changing the temperature of a magneto–optical trap in the process of photoassociation. The high-order scattering partial wave is directly manifested through the large signal amplitude of the rovibrational resonance levels of trap-loss spectroscopy from photoassociation.     

用电离光谱技术测量钾分子激发态的振动常数

用染料激光激发钾蒸气，观察到了与钾分子电子态5^3Hu振动能级相关的电离谱，根据电离谱峰对应的激光波长值计算出了钾分子5^3Hu态的振动结构常数，在实验误差范围内与Magnier和Millie的理论计算结果一致。     

封闭和开放铯原子系统中的EIA效应

本文主要从实验上研究了封闭的简并二能级铯原子系统中的电磁感应吸收效应(EIA)。当泵浦和探测光作用于铯原子的6S1/2 F=4 à 6P3/2F′=5跃迁时，获得了EIA信号，同时研究了泵浦光的频率失谐和强度对EIA信号的影响。在6S1/2 F=4 à 6P3/2 F′=4和6S1/2 F=4 à 6P3/2 F′=3两个开放的二能级系统中也观察到了EIA信号。在6S1/2 F=3 à 6P3/2 F′=4的跃迁上增加一个repumping 激光,将使EIA信号增加。     

Thermal-energy Pooling Collisions in Cesium Vapor 6P_(3/2) 6P_(3/2) →7P_J 6S_(1/2)

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背景噪声对单分子光子统计的影响

我们利用HanburyBrown和Twiss探测方法来记录两个单光子计数器响应单分子源输出的每一个事件 ,直接计算触发式单分子光子源的Mandel参数Q。通过对触发式单分子源的Mandel参数QRS与含有相同平均光子数的具有Poisson分布的相干态的Mandel参数Qc进行比较来确定光子源统计分布特性。研究得到了一种计算触发式单光子源信噪比 (SBR)有效的方法。     

Research on the distributed optical remote sensing of methane employing single laser source

A design and testing of a cost-effective distributed optical remote sensing methane system, which will help one to detect gas leaks from multi-coal face in mines simultaneously, is presented. The fundamentals of the remote detection are based on frequency-modulation spectroscopy (FMS) and harmonic detection. By utilizing fiber-optic splitting technique and reference-signal restoring circuit, the remote sensing system is feasible to employ single laser source to get multi-spot measurement in the near infrared region so that the system described here shows sufficient sensibility, considerably increased reliability and marketability over the presently available system. The minimum measurable path-integrated concentration is estimated to be about 423 ppb-m by experimentation.     

利用双光缔合光谱技术直接测量超冷铯分子0u+(6S1/2+6P1/2)长程态的转动常数的实验研究

实验获得了超冷铯分子6S_1/2+6P_1/2离解限下0_u⁺长程态振动能级v=187的转动常数. 首先利用调制的荧光光谱技术获得了高分辨的转动量子数J=0–6的超冷铯分子纯转动光谱. 利用双光缔合光谱技术, 构建了高精度的频率参考信号, 进而得到了相邻转动能级间的频率间隔. 最后通过非刚性转子模型拟合得到了转动常数和离心畸变常数.     

电流调制激光引入的非稳散粒噪声的测量

利用锁相放大器,结合对Labview 软件编程,研究了电流调制激光引入的非稳散粒噪 声。通过对噪声功率谱的多次平均和快速傅立叶变换,有效地测量了非稳散粒噪声的频谱特性,研究结果表明非稳散粒噪声具有确定的相位依赖特性。