TE_(oln)模螺旋谐振腔

本文讨论TE_(01n)模螺旋谐振腔及其在电介质测量、螺旋波导的衰减测量、长度测量和高损耗材料电性能测量等方面的应用,此外还讨论大尺寸谐振腔在8mm波段的电介质测量。     

平面光波在电介质表面的反射特性仿真研究

文中根据麦克斯韦电磁理论,利用电矢量和磁矢量来分析光波在两介质表面的反射特性,把平面光波的入射波、反射波和折射波的电矢量分成两个分量:一个平行于入射角,另一个垂直于入射角,对平面光波在电介质表面的反射和折射进行分析,推导了菲涅尔公式,并结合MATLAB研究光波从光疏介质进入光密介质,以及光波从光密介质进入光疏介质时的反射率、透射率、相位等随入射角度的变换关系。同时对光波在不同介质中传播时的特性变化进行仿真研究,根据仿真结果分析了布鲁斯特角、全反射现象及相位变化的特点。有关各量的平行分量与垂直分量依次用指标p和s来表示,s分量、p分量和传播方向三者构成右螺旋关系。     

电感调谐的同轴谐振腔中TMs10模电场分布的研究

圆柱型同轴谐振腔中的横磁模TMs10的电场分量沿圆周方向呈周期性均匀分布,电感调谐的圆柱型谐振腔的圆周边界不再规则,腔内场分布的均匀性遭到破坏。为了能准确描述场分布的情况,该文建立了不规则圆周边界的同轴谐振腔的物理模型,通过理论分析得出了边界发生变化时同轴谐振腔中电场分布的变化规律。并通过三维电磁场软件进行了数值模拟,模拟结果与理论分析所得结论一致。     

TM020模多注速调管圆柱谐振腔的仿真设计

根据微波电磁场理论设计了工作于L波段的TM020模圆柱谐振腔,由模式场分布图结合数学方法确定出漂移管在谐振腔中的位置,利用三维电磁场仿真软件Isfel3D对空腔及腔体加漂移管后进行仿真,得到了加漂移管前后谐振腔的特征参数和模式场分布图,同时将模TM020与基模TM010进行比较,证明工作于TM020模式的谐振腔可以增大谐振腔的体积,减小阴极负载,提高谐振腔的功率容量.     

氯流量为10mmol／s的高效超声速氧碘化学激光器

对体积不大的超氧碘化学器进行了实验参数研究。表明当碘蒸气加进单态氧的揉合点从亚声速转移到超声速时，气体流动和氮温降低可提高激光输出功率。当谐振腔中的马赫数为１．５及氮８流量为１０ｍｍｏｌ／ｓ，时，得到２００Ｗ的功率。表明所有的气体流量及单态氧发生器中的压力增加１．６倍，     

光电子技术

0622847红外准动态图像平台的设计和实现[刊,中]/钟文辉//激光与红外．—2006,36(6)．—459-462(G)介绍了一种用于红外焦平面成像仪参数客观测量的红外准静态图像采集和处理平台的设计与实现。该平台可从动态视频流中以任意格式抽取出任意一帧的数据,用CPLD和DSP自动对其进行处理及分析,并把图像数据通过USB2．0高速总线传回PC,进行保存、显示及检验平台处理的结果。该平台再配合外围探测器和其它器件可方便地对红外热像仪各项参数(NETD、MRTD、MTF)进行客观测量。参7 0622848热透镜谐振腔参数对指向精度的影响[刊,中]/路鑫超//激光与红外．—2006,36(6)．—448-451(G)从谐振腔理论出发,论证了谐振腔参数与谐振腔灵敏度对热透镜谐振腔指向精度的影响,计算了经过优化后的热透镜谐振腔参数,并通过实验测量了不同谐振腔参数下输出激光的指向精度。实验结果表明,优化后的热透镜谐振腔具有较高的指向精度。参6     

X波段同轴腔多注速调管的研究

开展了具有同轴谐振腔互作用电路和双模工作杆控电子枪的X波段同轴腔双模多注速调管的研究工作．结合数值计算和冷测实验，对工作于TM310高次模的同轴谐振腔模式分布和特性参数进行研究，获得了可满足多注速调管要求的谐振腔特性阻抗和良好的模式稳定性．采用具有双控制极的新型杆控多注电子枪及电子光学系统，可使多注速调管具有双模的新工作特性，通过数值模拟获得了优化的几何参数和具有良好层流性和波动性的空心多电子注．对采用6个电子注和5个谐振腔的X波段多注速调管进行了注波互作用大信号计算，结果表明当电子注电压为21．5kV，脉冲电流为14．4A时，可在30MHz频带范围内获得的100kW左右的脉冲输出功率，互作用效率大于30％，增益大于36dB．     

可实现连续激光-脉冲转换的全光纤声光耦合环形谐振腔

研究了光纤声光耦合环形腔独特的谐振特性。结果表明利用光纤声光耦合器的移频与滤波特性 ,可研制成一种全新结构的光纤声光耦合环形谐振腔。从理论和实验上证明了 :基于腔内累积声光移频分量的多光束干涉 ,光纤声光耦合环形谐振腔可将注入的连续激光将转换为脉冲列输出。     

Comparison of Mode Quality Factors for Equilateral Triangular,Square and Rhombus Optical Micro-Resonators

采用时域有限差分和Padé近似计算了等边三角形、正方形和平行四边形微谐振腔的模式频率和品质因子．数值结果表明等边三角形谐振腔中的谐振模式具有较高的品质因子,这主要是由于等边三角形谐振腔中的模式在横向上得到了完全的限制,而在其它两种谐振腔中,模式在横向上只是得到部分限制．对于边长为4μm,折射率为3.2的等边三角形谐振腔,发现在1.55μm波长处的模式品质因子可达5.5×103．     

一种分析谐振腔的新方法

报道一种分析谐振腔、特别是多元件谐振腔的新方法—辅助参量方法．分析了这组参量的物理意义和特性。并用此方法给出了谐振腔各主要物理量的解析表述．     

New linewidth enhancement determination method in semiconductor lasers based on spectrum analysis above and below threshold

Linewidth measurements of singlemode and multimode InGaAsP lasers were made above and below threshold with adapted interferometers. Linewidth against inverse power plots Delta nu =f(1/P), show different Schawlow-Townes slopes above and below threshold. Differences have been observed depending on singlemode or multimode laser behaviour. In the singlemode case the linewidth enhancement factor has been determined ( alpha =2.6) by extrapolating and correlating results above and below threshold.<>     

10kV及以下配电电缆的运行维护

当前我国的电力行业在发展中使用10kV及以下配电电缆的频率较高,而10kV及以下配电电缆在我国的电网建设中的覆盖面积也愈来愈广泛,但是10kV及以下配电电缆在长期的使用中会出现一定的问题,最终影响10kV及以下配电电缆的正常使用,这对于我国电网的运行十分不利,本文将对10kV及以下配电电缆的运行维护问题进行分析,望给相关从业人士提供参考.     

用于微波组件的LTCC Wilkinson功分器设计

基于LTCC工艺,设计了一种可用于微波组件的新型三维Wilkinson功分器,设计指标为:工作频带介于2.2～2.7GHz,插入损耗<0.5 dB,隔离度>20 dB,驻波比<1.30.使用HFSS软件为该功分器建立了模型并进行了仿真计算.仿真结果表明:该功分器在工作频带内的插入损耗<0.3 dB,隔离度>20dB,驻...     

采用粉末溅射的薄膜型气敏元件与测试特性

利用粉末溅射,研究了 SnO2/CeO2微型平面薄膜。结果表明:薄膜最佳掺杂范围(5%~20%)、最佳灵敏度膜厚(150 nm)、响应时间与恢复时间随膜厚变化遵循次方定律;制备出稳定性好的气敏元件,灵敏度 S 为 20~80,对航空汽油气选择性 Sl为 8~20,响应时间τs<10 s,恢复时间τc<15 s。并对影响灵敏度测试的条件,例如测试电压、湿度影响、反应温变等进行了分析。     

Automatic General-Purpose Microwave Circuit Analysis Programs

The panel members were asked to respond to the Editor's question, given below. They were then given copies of each others comments, and asked to respond with a second-round of opinions.     

The Status of Computer-Oriented Microwave Practices (Panel Discussion)

The panel members were asked to respond to the Guest Editor's questions, given below. They were then given copies of each other's comments and asked to respond with a second round of opinions.     

Tapered slotline antennas at 802 GHz

Broken linearly tapered endfire slotline antennas (BLTSAs) were fabricated on 1.7-μm thin SiO₂-Si₃N₄ dielectric membranes. Antenna patterns in the E-, H-, and D-planes were measured at 802 GHz. The -10 dB beamwidths were found to be approximately 40° in all planes, with side lobe levels below -11 dB (-19 dB in the E-plane). The cross-polarized peaks in the D-plane were 8 dB below the copolarized peak. A theoretical model for calculating the E- and H-plane patterns of tapered slotline antenna 10 is extended to include the co- and cross-polarized D-planes. Measured and calculated patterns show good agreement     

Trapping levels in silicon nitride

The trapping levels in silicon nitride have been investigated using the thermally stimulated current technique. Traps at between 0.50 and 0.90eV below the conduction band of the nitride were found, as well as a distribution of traps at and near the silicon-silicon nitride interface about 0.10eV below the conduction band of the silicon.     

Reliability of metal interconnect after a high-current pulse

In certain situations, very large scale integration (VLSI) metal interconnects are subjected to short duration high current pulses. This occurs in FPGA programming, and in radiation testing for latchup. The authors have determined the effects of such pulsing on the long term reliability of Al (1% Cu) metallization with W cladding on top and bottom. The reliabilities of pulsed and unpulsed lines were established using accelerated electromigration testing. Lines pulsed below the immediate catastrophic threshold were seen to have slightly improved electromigration lifetimes, but as the failure threshold is approached, electromigration lifetime decreases abruptly. Therefore, high current pulsing provides no reliability hazard in this metallization system below catastrophic threshold     

Avalanche breakdown in multicrystalline solar cells due to preferred phosphorous diffusion at extended defects

Multicrystalline solar cells break down strongly at reverse voltages well below the theoretical limit. Previous explanations were based on assuming a constant depth of the junction below the surface. In this work, preferred phosphorous diffusion at special line defects in grain boundaries is shown to lead to spikes in the p–n junctions even below flat surfaces. The curvature radii of the spherical p–n junction bending are measured by electron beam‐induced current to be in the range of 300–500 nm, leading to the observed type III avalanche breakdown voltages. Copyright © 2012 John Wiley & Sons, Ltd.