On the role of the local oscillator intensity in optical homodyne-like tomography

In a recent research (Olivares et al., 2019 [18]) we have demonstrated that a homodyne-like scheme, exploiting a “low-intensity” local oscillator, can be used to perform optical state tomography of both quantum and classical states of light. The reconstruction method directly uses the homodyne-like probability distribution retrieved from the detector. Here, we further investigate the role played by the local oscillator in this respect. In particular, we study to some extent how its intensity affects the quantum-state reconstruction procedure by focusing on the case of the Fock states |1〉 and |2〉, whose homodyne-like probability distributions are sensibly affected by the actual value of the LO intensity. The analysis is performed on Monte Carlo simulated experiments taking also into account the quantum detection efficiency.     

混合集成微型光纤光谱仪的实验测定

文中简述了所研制微型光谱仪的基本原理和基本结构,并对该微型光谱仪进行了实验测试和标定。在实验中采用汞灯作为测试所用的光源,分别使用不同芯径和数值孔径的光纤作为光输入元件,实验结果表明该光谱仪具有很好的线性度,在采用50μm的多模光纤时,光谱分辨率可达13.8nm,在采用9μm的单模光纤时分辨率可以达到5.5nm。     

强流脉冲相对论电子束加速器：—闪光二号

本文介绍了在西北核技术研究所建成的一台低阻抗脉冲电子束加速器——闪光二号。它主要用于核辐射效应模拟。加速器系统由Marx发生器、水介质同轴线和二极管三大主机部件以及十几个配套设备所组成。文中给出了在允电电压±55kV和±70kV两个电压等级下调试和运行的结果。最大输出电流600kA,管电压1.2MV。目前该加速器已用于电子束和X射线的实验研究。     

长波长1.3μm直接调制InGaAsP/InP半导体激光器产生超短光脉冲

利用长波长1.3μm InGaAsP/InP半导体激光器,在直接调制下获得了重复频率为1GHz,脉宽为19.3ps的超短脉冲。     

牙齿磷光检测技术研究

本文分析了牙齿磷光测量技术一直不能进一步发展的原因,提出了一种新的检测技术。这种技术利用光纤传输紫外光和磷光,利用光电接收器作为传感器,解决了牙齿磷光现象一直不能定量分析的问题,使得牙齿磷光现象与牙齿疾病之间关系的研究得到了进一步的发展。     

激光辐射CCD的破坏机理分析

 研究了国内外关于激光辐照CCD及其相似材料结构导致的各种效应, 特别是软硬破坏效应, 给出了各种破坏的阈值及实验方式; 对各种破坏机理及理论模型进行了对比分析。     

A position- and time-sensitive particle detector with subnanosecond time resolution

A microchannel plate/CCD-camera particle detector is described that utilises gold strips deposited upon the surface of a MCP to provide particle arrival time information. The uncertainty in the timing is assessed to be ∼500 ps (FWHM) for a measured time interval between adjacent strips. The main contribution of which is the result of the slow response time of the CFD compared to the signal. The application of timing measurement is shown to be of particular benefit in the accurate determination of product state branching ratios from the dissociative recombination of diatomic ions. Finally, the possibilities of such a detector are assessed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Selective determination of organofluorine compounds by capillary column gas chromatography with an atmospheric pressure helium microwave-induced plasma detector

Fluorinated analogs of compounds typical of those found in metabolic and other biological studies are detected with high selectivity using a gas chromatograph/microwave-induced plasma detector (GC-MIPD), which permits fluorine-selective detection by monitoring the emission at 685.6 nm. Using the described atmospheric pressure helium-sustained plasma detector, the minimum detectable level, fluorine selectivity (relative to carbon), and linear dynamic range of this GC-MIPD system were determined to be 4.8 pg-F/s, 1060, and 5000, respectively. The utility of this GC-MIPD system for the selective detection of organofluorine compounds is demonstrated by its application in the analysis of the metabolic fate of a fluorinated substrate administered to a mixture of wheat germ phosphatase and potato apyrase, as well as by analysis of synthetic mixtures.     

Design of a laser pointer

A laser pointer has been designed using a red diode laser (670 nm). The optics of the pointer consists of a four element collimating lens, two prism compressor and a two lens reversed Galilean afocal. The beam diameter of the laser pointer is 4.2 mm.     

一种新型的红外成像材料

基于超大磁阻(CMR)材料在绝缘体—金属转变(I—M)点附近的巨大电阻变化，本研究了La位Gd掺杂对La0.7-xGdxSr0.3MnO3(x=0.20、0.30、0.40、0.50)电阻温度系数(TCR)的影响。实验结果表明：Gd掺杂将引起电阻率曲线的急剧变化，导致出现大的TCR；而且随Gd掺杂的增加，TCRR在x＝0．30出现峰值，然后随掺杂量增加逐步降低，大的TCR行为将成为新型的红外成像材料。