高斯积分在量子表象理论中的应用

首先证明了真空投影算符的正规乘积形式,然后结合有序算符内积分技术,把数学上的高斯积分推广到量子算符的积分形式.通过表象的完备性与对称性,进一步给出了坐标表象、动量表象、中介表象和相干态表象的具体形式.     

半外腔Nd:YAG和Nd:YVO4微片固体激光器的腔调谐特性研究

微片固体激光器具有体积小、寿命长等优点,是精密测量仪器的重要光源。构建了平-平、半外腔的Nd:YAG和Nd:YVO₄微片激光器,通过控制压电陶瓷伸缩改变激光器的谐振腔长,同时使用F-P扫描干涉仪和波长计观察纵模和波长。研究了这2种微片固体激光器的腔调谐特性,包括腔长与光功率的关系,激光纵模扫过出光带宽过程的光功率和单、双纵模变化的规律。实验结果表明：腔调谐过程中单、双纵模交替出现,腔长和泵浦电流共同影响激光器的输出模式和光功率。     

基于联合特征与Bi-LSTM模型的英汉双语文本情绪预测

英汉双语文本中的情绪可以通过英语和汉语的单语或者双语形式来表达。然而,以往的研究主要集中在单语文本的情绪分析,只有少数研究侧重于英汉双语文本。为提高英汉双语文本情绪预测效果,本文结合情绪词典方法与深度学习方法,使用联合特征与Bi-LSTM模型来对英汉双语文本进行情绪预测。首先基于情绪词典抽取出双语文本中包含的情绪词特征,然后联合情绪词特征与双语文本特征输入至Bi-LSTM模型进行特征学习,最后将学习到的深度语义特征输入到分类器中进行情绪预测。实验结果表明,该方法对英汉双语文本的情绪预测有良好的效果。     

Evolution of Number State to Density Operator of Binomial Distribution in the Amplitude Dissipative Channel

We show that passing through the amplitude dissipative channel the initial pure number state density operator is evolved into the density operator of binomial distribution （a mixed state）, and the binomial distribution parameter is just equal to e^-2kt, where k is the dissipative parameter of the channel. We solve the corresponding master equation to obtain the operator-sum representation of the density operator by virtue of the entangled state representation, which seems to be a convenient approach.     

基于金属表面等离子激元控制光束的新进展

表面等离子激元(Surface plasmon polaritons,SPPs)是一种在金属-介质界面上激发并耦合电荷密度起伏的电磁振荡,具有近场增强、表面受限、短波长等特性,在纳米光子学的研究中扮演着重要角色。近年来表面等离子光学和基于SPPs的纳米光子器件的研究引起了国际上科学家们的广泛关注。讨论了SPPs的基本原理和在亚波长结构下的光学特性,介绍了基于亚波长金属结构的表面等离子激元在空间光束准直与聚焦、平面内光束聚焦与传导和在近场纳米光束的控制等方面的研究情况,以及在纳米光子学器件中的潜在应用。     

Generation and Modulation of Phase Difference of Output Intensities in a Feedback Nd:YAG Laser with an Extracavity Waveplate Rotated

External anisotropic feedback effects on the phase difference behaviour of output intensities in a microchip Nd：YAG laser are presented. By rotating a quarter wave plate placed in the external cavity, the angle between laser initial polarization direction and o-axis of the wave plate is tuned from -45°to 45°, which results in variable extra-cavity birefringence along two orthogonal detection directions. With only one optical path and one wave plate, laser intensities of the two orthogonal directions, both modulated by the external cavity length, are output with a tunable phase difference, which can be continuously changed from zero to twice as large as that of the waveplate. Experimental results as well as a theoretical analysis based on Fabry-Perot cavity equivalent model and the refractive index ellipsoid, are presented. The potential applications of this phenomenon are also discussed.     

External-cavity birefringence feedback effects of microchip Nd:YAG laser and its application in angle measurement

External-cavity birefringence feedback effects of the microchip Nd:YAG laser are presented.When a birefringence element is placed in the external feedback cavity of the laser,two orthogonally polarized laser beams with a phase difference are output.The phase difference is twice as large as the phase retardation in the external cavity along the two orthogonal directions.The variable extra-cavity birefringence,caused by rotation of the external-cavity birefringence element,results in tunable phase difference between the two orthogonally polarized beams.This means that the roll angle information has been translated to phase difference of two output laser beams.A theoretical analysis based on the Fabry-Perot cavity equivalent model and refractive index ellipsoid is presented,which is in good agreement with the experimental results.This phenomenon has potential applications for roll angle measurement.     

环形激光弱磁传感器误差分析

本文从理论上分析了环形激光弱磁传感器主要误差因素并提出了若干克服这些因素的方法。这些误差因素是:大尺寸的法拉第室引入的噪声,磁光材料的费尔德常数的温度系数,塞曼效应的混入、朗谬尔效应等。     

弱磁场下法拉第效应的实验研究及可能应用讨论

利用了四频环形激光对磁场的高度敏感性测量了Tb玻璃(磁场范围0.8×10~(-5)T(Tesla)～10~(-9)T,ZF_2玻璃(0.21×10~(-4)T～1.89×10~(-4)T的费尔德常数(Verdet constant).在本实验精度范围内,得到了该常数大小和强磁场下的值一致.以此实验结果为基础,简要地讨论了用置于环形激光中的法拉第磁光材料感测地磁场的构思和发展前景.     

光学系统球心偏公差的优化制定方法

提出了一种简便、实用的制定光学系统球心偏公差的优化方法。