高功率微波高斯馈源口面场分析

 用波导本征模展开方法对用于高功率微波发射系统的方角锥高斯馈源口面场进行分析，提出结合馈源远场辐射特性和避免高功率击穿折衷选定相应的高斯模注腰半径，进而确定多个波导模幅值，从而为运用模匹配或耦合波理论设计高斯馈源提供依据。     

关于近代物理实验教学的思考

本文从教学模式、教学方法、开放实验、专题讲座几方面提出了关于提高近代物理实验教学质量的一些设想。     

THE DESIGNS OF HIGH EFFICIENCY LAUNCHER OF QUASI-OPTICAL MODE CONVERTER FOR HIGH POWER GYROTRONS

A high efficiency launcher of quasi-optical (QO) mode converters for high power gyrotrons have been designed and tested. A helical cut launcher radiates the RF power via its straight cut onto the first phase correcting mirror. The launchers have been optimized for the TE_31.8 mode at 170 GHz and TE_22.6 mode at 110 GHz by numerically optimizing a launcher surface. The helical cut of the launcher has been optimized by taking the taper angle into account. Further more, the amplitude of the surface perturbation have been optimized for improved focusing in order to reduce the diffraction losses at the helical cut. Low power measurement shows a good agreement with the design. High efficiency characteristics of the design have also been calculated on the assumption of frequency downshift due to the thermal expansion of the cavity and stepwise frequency tuning by changing the operating mode. Besides, the possibility of high efficiency launcher for higher mode is discussed, and these results give the prospect to high efficiency long pulse gyrotrons.     

等效可变孔径远场法测量单模光纤模场半径

本文提出等效远场的可变孔径方法,由测量光纤远场累积分布求得模场半径。并且利用Petermann关于模场半径的新定义,推出了一种对非高斯模场分布也适用的求模场半径的方法。实验表明,这种测量方法简便可靠,在不同的制备端面下,重复测量的标准误差小于0.04μm。     

数据库应用综合设计实验改革初探

文章对数据库应用的综合设计性实验改革工作进行了总结，给出了一种既能培养学生的创新能力又可以节约学校资源的实验模式。     

利用模式的对称性研究光子晶体光纤的色散

由光子晶体光纤的对称性可以得到模式分布的对称性，根据模式的对称性选择适当的展开函数，可以使计算量大大减少。计算了六角结构光子晶体光纤的色散特性，得到了波长在1．55pm处色散为零时，光子晶体光纤的结构参量所满足的方程。     

单壁碳纳米管的SERS研究

本文通过改进实验方法,将单壁碳纳米管的乙醇溶液与金胶混合并制作成固体薄膜,使单壁碳纳米管夹裹在金纳米粒子之间,保证了吸附的紧密性,获得了高质量的单壁碳纳米管SERS光谱。不但观测到文献中报道的径向呼吸振动模(RBM)和C-C正切拉伸模(GM)的增强,还在1100-1500cm-1区域观测到一组新峰,其峰形完整并有相当的强度。这些峰在现有的文献中几乎没有报导。文章对这组新峰的出现进行了初步的分析。     

激发相干态下双模介观传输线的量子效应

将介观无损耗传输线中的驻波场看成作相对运动的两列同频率的行波的叠加，此电路量子化后成为两个频率相同、不同模的光子场。计算和分析了激发相干态下电压和电流梯度的量子涨落，指出了双模传输线与一般的LC电路、双模传输线与单模传输线量子涨落的异同之处。     

Applying a Mode Selector to Improve the Pulse-Compression Performance of Asymmetric-Coupled-Waveguide-Based Dispersion Compensators

An InGaAsP slab-type asymmetric-coupled-waveguide-based dispersion compensator with a mode selector has been designed and fabricated. The mode selector is necessary to select either a symmetric [with a positive group-velocity dispersion (GVD)] or antisymmetric (with a negative GVD) supermode. These supermodes exist simultaneously in the dispersion-compensation region of the device. Pulse-compression experiments were used to test the dispersion compensator, evaluating the function of the mode selector. A theoretical study of the experimental results shows that the mode selector obtains a very strong selectivity (nearly 100%) for the antisymmetric supermode.     

CRP复合材料板复合型裂纹扩展方向预测理论研究

本文对碳纤维增强的复合材料板裂纹扩展方向预测理论进行了研究。介绍了最新发展起来的复合材料Z断裂理论 ,并通过试验证明了新理论的正确性