半导体激光器光栅外腔光谱合束技术研究进展

半导体激光器由于受波导结构和芯片封装等因素的限制,其快慢轴方向上的光束质量差距较大,主要用作抽运源,即被当成亮度转换器使用,很难作为高亮度光源直接应用。介绍了提高输出光功率密度和输出光束质量的非相干合束技术——光栅外腔反馈光谱合束技术,以及近几年来的国内外的发展现状,梳理了半导体激光器外腔光谱合束技术发展的若干重要动向,为以后半导体激光器光谱合束技术的发展提供了参考。     

微型阵列束闸电子束偏转特性研究

为了降低微型阵列式束闸边缘场和邻近电场对多束电子束的偏转影响和串扰，本文以3×3阵列束闸为研究对象，利用COMSOL Multiphysics中的静电和带电粒子追踪模块，研究束闸长宽比、隔离接地极和束闸上方增加接地层对电子束偏转的影响。研究表明，在长宽比不变的情况下，边缘场对电子束偏转的影响在总偏转量中的占比与偏转电压无关；而偏转极板的长宽比越大越有利于精确控制电子束的偏转；通过优化隔离接地电极结构与参数，可减小束闸之间的串扰引起的束斑模糊问题。为了减小边缘场和邻近电场对电子束偏转的影响，本研究分析得出，如果束闸上方接地层的作用范围小于100μm,可在一定程度上抑制串扰的影响。同时，分析表明将接地层上圆孔改为方孔后，也在一定程度上减小了不平衡电场带来的影响。     

基于光纤束的物镜设计与监控系统实现

为保证电气电子设备在辐射抗扰度试验中状态传输的稳定性，设计并实现了适用于试验环境的光纤束监控系统。系统主要由物镜、光纤束、转接镜和电荷耦合器件等组件构成。通过Zemax光学仿真软件，结合光纤束参数设计并优化了监控系统的物镜。设计结果表明：物镜在空间频率36 lp/mm处，各视场光学调制传递函数值大于0.8，像面大小与光纤束尺寸匹配，满足像方远心光路要求。对加工的物镜进行性能测试，表明其技术指标与理论设计比较相符。采用搭建的光纤束监控系统进行成像试验，并运用高斯滤波算法进行去像素化处理，提高了监控系统的视频传输质量，辐射抗扰度试验表明此系统具有良好的抗电磁干扰能力。     

超导电子学展望

本文综述近十年来超导电子学的一些主要进展,特别对SIS准粒子检测器,混频器,微波接收机,新电压基准以及新型高速模拟信号处理技术等作一简单介绍。和常温电子器件相比,超导电子器件的特点是“两高两低”。所谓“两高”,是指“高速率与高灵敏度”。所谓“两低”,是指“低功耗与低噪声”。文中指出,超导电子器件所具有的这些独特的优良性能,都应归结于低温条件。最近国际上出现了“超导热”,国内各有关科研单位也都在研制高Tc的超导材料。但是,必须注意,提高超导材料的转变温度,可使器件在较高温度下工作,但由于较高的热噪声电平,器件的一些独特的优良性能可能被牺牲了,因此,高Tc超导材料的发现,决不意味着在一切超导应用中,都可以降低致冷要求。     

电视摄象管的电子光学结构

从工程实际角度,用定性分析的方法,对电视摄象管(主要侧重于光导视象管、超正析象管、返束视象管等)的电子光学结构(包括电子枪与聚焦、偏转系统)进行了较全面的概括性综述和剖析。并简明扼要的叙述了电视摄象管与电视技术的关系及其发展动向。仅供从事电视摄象营的研制和应用的人员参考。     

精密光路偏转及焦距调整机构的发展

介绍了压电陶瓷和音圈电机在精密光路偏转和焦距调整机构的原理和发展状况;分析了偏转与调焦机构的主要结构形式、驱动特点及其在精密偏转与调焦机构中的应用前景;指出了需要进一步开展研究的关键技术.     

专利文献介绍

将<字形电子束朝所定方向进行扫描,从而在束扫描方向上形成凸型固液界面。具体结构如下:将第一电子枪发出的电子束,通过高速偏转电极进行高速偏转,第二电子枪发出的电子束通过另一对高速偏转电极进行高速偏转,得到两个直线状     

磁旋管(综述)简介

磁旋管脉冲功率可达５００－１０００ＭＷ,效率高达６０－８０％,增益３０－６０ｄＢ。结果是一些简单的圆柱腔所组成,工作于旋转的ＴＭ１１０模式。利用圆偏转机构和相对论范围的高速度获得高功率和高效率,属于偏转调制器件,本文综述了磁旋管的参数、结构、工作原理和动力学理论。     

声光偏转工作模式及其应用研究

从声光偏转器对光束产生偏转的原理进行了讨论.根据声光偏转器件的工作方式分别归纳和介绍了声光偏转器在各个领域的应用研究.并提出了利用声光偏转器实现时间域信号向空间域转换的新思想.     

不同几何结构电光偏转器比较研究

为了发展性能优良的电光偏转器,采用傍轴近似分析了级联棱镜电光偏转器的折射率梯度等效表达式,总结出了不同几何结构电光偏转器的偏转角和偏转轨迹公式,在此基础上比较研究了4种不同几何结构电光偏转器的偏转特性和偏转轨迹,比较分析了梯形、喇叭形和抛物线形几何结构电光偏转器的偏转灵敏度,为较大角度电光偏转系统的设计提供了有意义的参考。     

Circular Waveguides Lined with Artificial Anisotropic Dielectrics

The propagation of electromagnetic waves inside circular waveguides lined with artificial anisotropic dielectric is investigated. Our investigation shows that the dominant hybrid electromagnetic (HEM/sub 11/ ) mode possesses a transverse deflecting field over the aperture of the structure and can be used as a transverse deflecting mode in a particle separator with ultrahigh energy. Expressions for power, attenuation, and transverse shunt impedance are obtained, and the effects of changing in loading on these various quantities are studied and presented in graphs.     

Monolithic two-dimensional GaAs/AIGaAs laser arrays fabricated by chlorine lon-beam-assisted micromachining

Chlorine ion-beam-assisted etching (IBAE) has been used to micromachine laser facets and deflecting mirrors for monolithic two-dimensional GaAs/AIGaAs laser arrays. Three laser cavity/deflector designs have been successfully implemented. The first utilizes a parabolic deflecting mirror to directly focus the laser radiation; the second consists of a folded cavity with a vertical facet, a top surface facet, and an internal 45° reflector; and the third has a folded cavity with an internal Al_0.2Ga_0.8As/Al_0.8Ga_0.2As dielectric mirror stack and a top surface facet formed in a single etch step with two internal 45° reflectors. The parabolic deflecting mirrors are currently modeled forf- 0.8 collection efficiency, making the first design attractive in incoherent arrays for high-power applications such as pumping Nd:YAG lasers. The other two structures are of interest for incoherent or coherent arrays used in high- and medium-power applications, since the top surface facets can easily be antireflection coated. The design with a dielectric mirror stack is particularly simple to fabricate.     

Analysis on electrostatic pattern yoke camera tubes

To investigate the features of electron-beam systems in electrostatic deflecting camera tubes, a method for calculating the deflection field of the twisted curved-arrow pattern yoke is presented using the method of separation of variables. In spite of three-dimensional analysis, field values at 2000 points can be calculated at 10^-3accuracy within 1 min using a HITAC-M200H computer. Distributions of deflection field also are given. Furthermore, deflection aberrations of electron beams are analyzed in the magnetic focusing and electrostatic deflecting (MS) systems. It is revealed that the favorable features of MS beam systems can be realized only by utilizing a nonuniform magnetic field. It is also seen that deflection aberrations and landing error are very dependent on a twist in the pattern yoke.     

Low threshold InGaAs/GaAs 45° folded cavity surface-emittinglaser grown on structured substrates

A novel folded cavity surface-emitting laser structure integrating a horizontal cavity InGaAs/GaAs laser grown on a structured substrate with a high reflectivity Bragg reflector has been fabricated. Devices with threshold currents of 8 mA and CW wall plug efficiencies at 5% at 6 mW output power have been demonstrated at a wavelength of 0.99 μm. By combining a cleaved uncoated mirror with the 45° deflecting mirror the authors have obtained threshold current as low as 5 mA for a device 450 μm long     

Perturbation Measurement of Transverse R/Q in Iris-Loaded Waveguides

The measurement of transverse R/Q in iris-loaded waveguides by perturbation techniques is described. The underlying pertrurbation theory for resonant cavities is reviewed, and formulas for metallic needles, a sapphire rod, and a teflon bead are given, A calibration of the perturbing objects in TM/sub 010/ and TM/sub 110/ cavities shows good agreement with theory. Conventional oscillator and transmission methods are compared, and a systematic error of the oscillator method is explained. A more sensitive null method is described. A definition of the transverse R/Q is given, from which it follows that the knowledge of the longitudinal electric field component is sufficient to determine the deflecting properties of a structure. The accuracy of perturbation measurements was tested on a cavity for which the R/Q was known from computer calculations and deflection tests. It was found that the various values agree to within 20 percent. Perturbation measurements of deflectors with small coupling holes showed the theoretically predicted interaction parameters. Values close to 2.2 k/spl Omega/ /m at 2.856 GHz were measured on a 2/3 /spl pi/ wave structure with about a 2-cm beam hole.     

具有弯折内导体同轴谐振腔的特性研究

对于具有弯折内导体的同轴谐振腔,采用模式匹配法,导出了能够准确求解其频率的本征方程,计算了腔体的场分布和功率容量.计算结果表明,文中引入的弯折内导体结构,不仅能够使谐振腔朝着小型化方向发展,而且还能使得场分布均匀化,得到更大的功率容量.其结果对于小型化谐振腔的设计具有一定的参考意义.     

电磁复合场中电子成像系统的计算机辅助分析

本文利用数值仿真技术对复合场中电子成像系统的像差理论做了研究。基于一种新的计算方法编写了一套完整的像差计算程序,由此可求得任意初始条件下复合场中电子成像系统的三级几何像差。其计算精度可比传统软件的提高四倍以上,为高精度电子光路的设计提供了可靠的理论工具。     

0.3T Ku波段返波管的低磁场特性研究

为了实现相对论返波管振荡器（RBWO）永磁包装,本文采用Magic模拟软件在0.5T低磁场相对论返波管（RBWO）器件结构基础上,通过在器件慢波结构末端添加一个部分反射腔,减小电子束质量对束波转换影响,即减小引导磁场的影响,实现了Ku波段相对论返波管振荡器0.3T磁场下运行.当电子束束压600kV、电子束束流7kA时,模拟得到器件输出微波功率740MW,效率18%.尽管该器件的效率低于0.5T磁场下的效率（25%）,然而0.3T引导磁场在工程上更容易实现.结合小型化的脉冲功率源进行实验研究,当二极管束压580kV、束流6.5kA,实验获得功率600MW,频率13.10GHz,脉宽25ns的微波输出,该器件的研制可以促进高功率微波（HPM）系统小型化的发展.     

基于瞬态微波光电导测试仪的谐振腔传感器设计

利用微波谐振腔微扰原理建立了应用于测量半导 体和发光材料的谐振腔的传感器模型。采用HFSS 仿真软件对谐振腔参数和结构进行仿真。仿真结果表明,采用矩形孔时,微波谐振腔中具有 符合实验要求 的电场形式以及电场强度;实验结果也表明,样品在采用矩形耦合孔的谐振腔获得了较强的 信号。将不同 的样品放置于谐振腔中,并用纳秒激光脉冲照射,获得了较理想的动力学曲线,证明该谐振 腔的实用性, 为下一步测量样品的介电常数和电导率等物理参数等实验奠定了基础。     

Radiation and Resonant Frequency of Superconducting Annular Ring Microstrip Antenna on Uniaxial Anisotropic Media

In this work, the full-wave method is used for computing the resonant frequency, the bandwidth, and radiation pattern of High temperature superconductor, or an imperfectly conducting annular ring microstrip, which is printed on uniaxial anisotropic substrate. Galerkin’s method is used in the resolution of the electric field integral equation. The TM set of modes issued from the cavity model theory are used to expand the unknown currents on the patch. Numerical results concerning the effect of the anisotropic substrates on the antenna performance are presented and discussed. It is found that microstrip superconducting could give high efficiency with high gain in millimeter wavelengths. Results are compared with previously published data and are found to be in good agreement.