Effect of staggered array structure on the flow field of micro gas chromatographic column

A new design of staggered array semi-packed micro gas chromatographic column was presented based on the micro electromechanical system(MEMS)technology.It was a sensor for gas sample analysis.The internal velocity fields of ten types of semi-packed micro gas chromatographic column were studied.The effects of array spacing and dislocation spacing on the flow field distribution were investigated.The results show that on the basis of ensuring the formation of virtual wall,with the increase of array spacing,the maximum velocity difference between the flow channels in the vertical direction decreases gradually,but the velocity difference in the flow channels a and b increases.When the inlet velocity was set to be 0.18 m/s,the maximum velocity difference in the channel of the staggered semi-packed micro gas chromatography column 3(CSAC3)was 0.05610 m/s.The maximum velocity difference in the channel a was 0.09160 m/s.The maximum velocity difference in the channel b was 0.02401 m/s.CSAC3 had a more uniform velocity field distribution,which can effectively suppress the laminar flow effect during chromatographic separation,and had a smaller pressure distribution,which puts forward lower requirements for carrier gas system.The staggered array semi-packed micro gas chromatography column proposed in this paper can effectively improve the velocity field distribution and pressure distribution in the channel,and provide a theoretical basis for the design of the new micro gas chromatography column structure.     

Quantum photonic network on chip

We provide an overview of quantum photonic network on chip. We begin from the discussion of the pros and cons of several material platforms for engineering quantum photonic chips. Then we introduce and analyze the basic building blocks and functional units of quantum photonic integrated circuits. In the main part of this review, we focus on the generation and manipulation of quantum states of light on chip and are particularly interested in some applications of advanced integrated circuits with different functionalities for quantum information processing, including quantum communication, quantum computing, and quantum simulation. We emphasize that developing fully integrated quantum photonic chip which contains sources of quantum light, integrate circuits, modulators, quantum storage, and detectors are promising approaches for future quantum photonic technologies. Recent achievements in the large scale photonic chips for linear optical computing are also included. Finally, we illustrate the challenges toward high performance quantum information processing devices and conclude with promising perspectives in this field.     

Λ型三能级原子与数态单模光场互作用系统的纠缠特性

通过计算场的量子力学熵讨论了Λ型三能级原子与数态单模光场互作用系统的纠缠和退纠缠时间演化规律.结果表明，系统的纠缠呈现周期性，最大纠缠度依赖于原子初态、初始场光 子数及场失谐量与耦合系数之比.一周期内出现最大纠缠和退纠缠的次数与初始场光子数无 关.近简并下能级初始相对位相影响场熵演化，而激发态和基态之间的初始相对位相对场熵 演化无影响.     

高浓度掺Er3+铌酸锂晶体的光谱参数计算

用提拉法成功地生长了6mol%的高浓度掺铒铌酸锂晶体。测量了晶体的两个非偏振方向(X和Z)以及两个偏振方向(π和δ)的吸收光谱。高浓度掺铒铌酸锂晶体的吸收系数高,有利于提高泵浦效率。根据所测的吸收光谱用Judd-Ofelt理论拟合出了Er3 离子的强度参数Ωλ。所得的均方差结果显示偏振拟合的误差要小于非偏振拟合。利用偏振吸收数据计算了各能级跃迁的自发辐射跃迁几率(AJJ′)、辐射寿命(τ)、荧光分支比(β)和积分发射截面(σp)等参数,对计算结果进行了讨论并与其他文献的报道结果进行了比较。     

Mode division multiplexed holography by out-of-plane scattering of plasmon/guided modes

We design and demonstrate a type of multiplexed hologram by nanoscatterers inside a dielectric-loaded plasmonic waveguide with guided-wave illuminations. The mode division multiplexed hologram(MDMH) is fulfilled by the scattering of guided waves to free space with respect to different modes. According to different mode numbers, these guided modes have different responses to the multiplexed hologram, and then give rise to different holographic images in reconstructions. In experiments, we show two kinds of MDMHs based on TM_0∕TE_0 and TE_0∕TE_1 modes as examples. Our approach could enrich the holography method that favors on-chip integration.     

BBO四倍频全固态Nd:YVO4紫外激光器

报道了用BBO晶体对激光二极管抽运Nd:YVO₄晶体声光调Q产生的1.064μm激光 进行四倍频,实现平均功率为63mW准连续波266nm紫外激光运转,重复频率为12.5kHz、单 脉冲能量5μJ、峰值功率达252W,绿光-紫外光转换效率达11%. 关键词： 266nm紫外激光 四倍频 全固态     

化学计量比LiNbO3晶体的激光显微拉曼光谱研究

对用助熔剂提拉法生长的近化学计量比LiNbO3晶体进行了激光显微拉曼光谱测试分析,与同成分LiNbO3晶体相比较,A1(TO)与E(TO)模的谱线数目、频率基本不变,验证了LiNbO3晶体属置换式固溶体的结论.738cm-1处拉曼振动峰（A1(LO)模）的相对强度随晶体中Li2O含量的增加发生了明显的变化,在两种掺杂晶体中,此振动峰已经消失.根据Li空位模型,从占位和结构上进行了分析讨论.在152和872cm-1处拉曼振动峰半高宽随晶体中Li/Nb的增大而变窄,对二者关系进行了线性拟合,利用拟合公式可根据拉曼振动峰半高宽计算晶体中的Li/Nb值. 关键词： 化学计量比 拉曼光谱 线性拟合 半高宽     

化学计量比LiNbO3晶体的畴结构及完整性研究

本文对用助熔剂提拉法生长的两种化学计量比LiNbO3晶体进行了测试分析,并与同成分LiNbO3晶体相比较.通过差热分析和X射线粉末衍射测试,得出随着晶体中Li2O含量的增加,其居里温度变高,晶格常数变小.用酸腐蚀晶体,通过直接观察和金相照片,分析其畴结构,得出SLN11是单畴生长,首次观察出SLN19晶体在Z切面上出现了三块面积较大的对称反畴区,将其称为区域性单畴.另外,还对晶体在(001)方向抛光面的不同位置测量了其回摆曲线,得到了其中SLN19晶体有着较完整的结晶面.期望通过改变生长参数,长出完全单畴且更加接近化学计量比的LiNbO3晶体.     

浅谈超构表面在量子光学中的应用

近年来,利用超构表面对光场的调控研究取得了令人瞩目的进展,不仅在经典光的调控方面取得了优异的成果,在量子光学方面的研究和应用也开始崭露头角,引起人们越来越多的研究兴趣。文章简要讨论了基于超构表面的量子光学的研究进展,包括量子光源的制备、量子态的调控以及量子态的探测和成像等方面。     

浅说人工微结构材料与光和声的调控研究

在过去的三十年里,人们在对光的调控方面进行着不懈的努力,取得了卓有成效的研究进展,其中突出的进展表现在诸如光子晶体的发展、等离激元学与亚波长光学的发展以及超构材料的发展等,文章简要探讨了当前超构材料和人工带隙材料等研究的几种发展趋势,展示了利用人工微结构材料实现对光和声的调控的美好前景.