852.3 nm激光线共振激发Cs蒸气的荧光光谱

研究了Cs蒸气被单模半导体激光器的852.3 nm线激发产生的荧光光谱。由Cs,Cs₂的荧光及其强度确定了在受激Cs-Cs₂系统中的若干碰撞和辐射过程。高位态原子线是由Cs(6P_3/2)+ Cs(6P_3/2)到Cs(6D,8S)的碰撞能量合并形成的,Cs₂(B 1∏_u)带则由Cs(6P)+Cs₂(X 1Σ+_g)碰撞转移产生。通过激发转移、能量碰撞合并和Cs₂-Cs碰撞传能研究了6 2P原子的精细结构混合,得到了6P_3/2→6P_1/2碰撞转移速率系数是(5.2±2.1)×10-11 cm3·s-1,给出了过程Cs₂(B 1∏_u)+Cs(6S)→Cs₂(X 1Σ+_g)+Cs(6P_1/2)的速率系数是(1.0±0.4)×10-9 cm3·s-1。     

大磁场梯度铯原子磁光阱中单原子的实验观测

基于中性原子的激光冷却与俘获技术,目前人们已可以对单个原子的外部乃至内部自由度进行有效的调控.从而可在单原子单光子的层次上对光场与物质的相互作用进行研究.     

利用锁相探测技术探测铯冷原子荧光谱的实验研究

通过俘获光频率调制,实现了铯冷原子荧光的锁相探测,得到了荧光谱信噪比改善52倍的结果.研究了锁相解调参量与荧光谱信噪比的关系;当灵敏度为1 mV和时间常量为1 s时,获得最大信噪比为204的荧光信号.     

The Effect of Collisions on the Resonance Fluorescence Spectrum of Three-Level Atoms with a V-Configuration of Levels

Optics and Spectroscopy - The effect of collisions on the resonance fluorescence spectrum of three-level atoms with a V-configuration of levels when excited by two monochromatic resonance fields...     

铯原子介质中受激拉曼四波混频的光放大特性

实验研究了在铯原子介质中受激拉曼四波混频过程中,注入的探针光与所产生的共轭光的增益特性,具体比较了在探针场分别作为Stokes场和Anti-Stokes场情况下,增益随粒子数密度、泵浦光频率失谐的依赖关系,并分析了其增益谱线线型和谱宽.为进一步开展基于受激拉曼四波混频进行量子关联光束的制备提供了主要实验参数的选择参考.     

Fluorescence Detection and Buffer Gas Cooling of Trapped Mercury Ions in Paul Trap

Pig ions are confined in a hyperboloid ion trap. With the rf discharge ^202 Hg isotope lamp, the fluorescence signal of trapped Hg ions is observed. By means of buffer gas cooling, the ionic temperature is reduced. As a result, the trapping time is increased and the signal-to-noise ratio （SNR） of the fluorescent signal is improved. The temperature of ion cloud is estimated by measuring the space charge shift.     

Ultra-High-Resolution Fluorescence Spectroscopy Upon Excitation of Atoms by Pulsed Radiation in Thin Gas Cells

Journal of Applied Spectroscopy - The method of sub-Doppler fluorescence spectroscopy is proposed and is based on the narrowing behavior with time of the velocity distribution of optically excited...     

Quasiparticle Spectrum of Quantum Degenerate Fermi Gas in the Presence of Self-Consistent Magnetization Field

In this paper, we develop a systematic and simple method to derive quasiparticle spectrum of the quantum degenerate Fermi gases within the framework of Hartree-Fock-Bogoliubov theory which turns a general nonlinear twobody interaction Hamiltonian into a bilinear Hamiltonian by introducing certain self-consistent mean fields. Applying the approach, we obtain the quasi-particle spectrum of the model describing the superfluid phase transition that arises when a Feshbach resonance pairing occurs in adiute Fermi gas in the presence of the magnetization fields m =U∑k and mk=U∑k.When the gap parameter △ is smaller than one or both of the magnetization fields, the spectrum manifests roton-type structure dramatically different from the spectrum in the absence of the magnetization fields.     

Velocity Distribution of Effective Atoms in a Small Optically Pumped Cesium Beam Frequency Standard

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Velocity Distribution of Effective Atoms in a Small Optically Pumped Cesium Beam Frequency Standard

In this paper, the velocity distribution of effective atoms in a small optically pumped cesium beam frequency standard has been achieved from the Fourier transforms of the experimentally recorded Ramsey patterns. The result fits well with the theoretical calculation. The second order Doppler shift correction of the small cesium atomic clock is obtained from the velocity distribution of effective atoms.     

油气样品的固定波长同步荧光光谱特征研究

固定波长同步荧光光谱是同时扫描激发波长和发射波长而获得的荧光光谱，具有图谱简单、窄化、光谱重叠少、干扰小等优点，通过在量油气的固定波长同步荧光光谱，提出不同性质油气的荧光光谱特征。将此技术应用于钻井岩屑分析可以判断油气的属性，用于地下水样和地表土壤样分析，可以判断下伏的含油气性，为钻井提供有利靶区。事实证明，固定波长同步荧光光谱和三维荧光光谱的指正是一致的，可以用简单、快捷的同步荧光谱分析代替三维荧光光谱分析，取得事半功倍的效果。     

科技考古课程教学中紫外可见吸收、分子荧光光谱实验教学设计

学习紫外可见吸收光谱、分子荧光光谱相关基础知识,并掌握相关实验操作和数据分析技能是科技考古专业研究生培养环节中的重要组成部分。针对目前科技考古专业研究生实际情况,通过设计紫外可见吸收光谱、分子荧光光谱实验对紫外可见吸收光谱、分子荧光光谱教学进行初步探索,取得较好效果。     

Emission Spectrum from Two Atoms in Bell States in a Cavity

By means of time-evolution operator, the emission spectrum from two two-level entangled atoms in Bell states interacting with a single-mode cavity field in the Fock state has been studied in the paper. The physical spectrum expression of radiation emitted by the atoms is given out for each Bell state. In general, the spectrum shows the symmetrical multi-peak structure and the symmetrical three-peak structure with the strong optical input. Bell states composed of two identical atoms can be partially distinguished in view of the characterizations of their emission spectrum.     

气相CBr2 自由基的产生及激光诱导荧光色散谱研究

利用双层流动反应管作为束源 ,研究了F与CH2 Br2 反应生成的CBr2 和Br2 的气相激光诱导荧光色散谱 ,将得到的谱线分别指定为CBr2 的 A(0 ,13,0 )→ X(0 ,v2 ″,0 ) (v2 ″ =1～ 6 )跃迁和Br2 的 B3 Π+ u → X1Σ+ g 跃迁 ,从光谱中首次得到气相CBr2 自由基基态弯曲振动频率ν2 ″ =2 15cm-1,实验确认了CBr2 自由基和Br2 是F +CH2 Br2 过程多步反应的产物     

Emission Spectrum from Two Atoms in Bell States in a Cavity

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Entanglement of Two Coupled Atoms in the Presence of a Time-Dependent External Magnetic Field

We study the problem of a time-dependent nonuniform magnetic field in the Heisenberg chain. We consider two cases: a single two-level atom and N-level atoms affecting by the magnetic field. We obtain the wave function and use it for calculating the expectation values of the dynamical operators, more precisely, the atomic inversion, in order to study the phenomena of revivals and collapses. Furthermore, we obtain the expectation value of other operators of the SU(2) group and discuss the phenomenon of squeezing. We show that the phase angle η and the detuning parameter δ are the most substantial parameters of the model under consideration.     

Quantum Dynamics of Cooled Atoms in the Presence of Bose—Einstein Condensates

Under the Markov approximation,the quantum dynamics of cooled atoms in the presence of Bose-Einstein condensates is studied.A master equation governing the evolution of such a system is derved.Using this master equation,the distribution of the atoms in the excited states at finite temperature and the dynamics of the excited atom at zero temperature are given and discussed.     

Measurement of Ionization Threshold of Ultracold Cesium Rydberg Atoms in Static Electric Field

We investigate the field ionization spectra of ultracold cesium Rydberg atoms in dc electric field. The ionization thresholds of different electric fields are measured and shift of the ionization threshold relative to field-free ionization threshold is accurately described by （6.06±0.14）F1/2, which is in good agreement with the classical saddle-point model for field ionization. We obtain the field-free ionization threshold of cesium （6P3/2） as 19674.89 ± 2.99 cm^-1 by fitting experimental data.     

近共振三维光学晶格中铯原子温度的参数依赖

介绍了四光束三维近共振光学晶格的方案,在铯原子磁光阱和光学粘团的基础上搭建了近共振光学晶格的光路,实现了光学晶格中冷原子的装载.利用短程飞行时间吸收法测量了近共振光学晶格中冷原子的温度,通过改变晶格的光强和失谐等条件,对近共振光学晶格中铯原子的亚多普勒冷却的参数依赖关系作了实验研究,并与光学粘团作了比较.