用光导开关产生高功率微波

用皮秒响应的光导开关激励λ／４同轴谐振腔，实现了直接从直流到射频的能量转换。用６１０ＭＨｚ、９５２ＭＨｚ和１６９６ＭＨｚ三个谐振频率进行了实验，在９５２ＭＨｚ处得到了最大输出；一个激励脉冲产生了约１４０个振荡周期。     

利用共振辐射压力获得准单一速度原子束

报道了利用行波场的共振辐射压力获得准单一速度原子束的实验研究结果，并进行了理论分析。实验上利用斜入射失谐为－１００ＭＨｚ行波光场共振作用原子束可使准单一速度原子束偏转１．７ｍｍ，速度宽度小于５８ｍ／ｓ。     

频率对双频超声辐照声化学产额增强效应的影响

本文采用电学法研究了２８ｋＨｚ分别与０．８７ＭＨｚ、１ＭＨｚ、１．７ＭＨｚ组成的双频超声辐照的声化学效应。结果表明，双频辐照增强声化学产额具有明显的频率效率。     

300MHz激光扫描声学显微镜

本文对激光扫描声学显微镜（ＳＬＡＭ）的刀口理论以及利用谐波技术提高其工作频率的方法进行了研究．实验上实现了使基波频率为１００ＭＨｚ的ＳＬＡＭ工作于３００ＭＨｚ三次谐波上．最后给出了一些样品在３００ＭＨｚＳＬＡＭ系统上较清晰的声学图像．     

二极管激光泵浦固体激光器和稳频研究

用调制法布里－珀罗干涉仪方法稳定二极管激光泵浦的ＮｄＹＶＯ４单频激光器的频率。在锁定情形下，激光频从自由运行慢漂移１．４３ＭＨｚ／ｓ和抖动±２．５ＭＨｚ分别改善到７５．７５ｋＨｚ／ｓ和±１ＭＨｚ     

用声透射损失测气一水混相介质中的含气量

本文利用超声检测中的穿透法,用频率为０．５ ＭＨｚ、 １ＭＨｚ、 １．２５ＭＨｚ、 ２ＭＨｚ、 ２．５ＭＨｚ的声波,测量了气一水混相介质中的声速比值和声透射损失。结果表明：在气泡大小、分布一定的情况下,可能用声透射损失来确定混相介质中的含气量,但不宜用声速比值．     

用声透射损失测气一水混相介质中的含气量

本文利用超声检测中的穿透法,用频率为０．５ＭＨｚ、１ＭＨｚ、１．２５ＭＨｚ、２ＭＨｚ、２．５ＭＨｚ的声波,测量了气－水混相介质听声速比值和声透射损失,结果表明,在气泡大小,分布一定的情况下,可能用声透射损失来确定混相介质中的含量量,但不宜用声速比值。     

中国人参的核磁共振研究Ⅰ．人参皂甙Re的二维核磁共振谱研究

用４００ＭＨｚ和５００ＭＨｚ超导核磁共振谱仪测定了具有生理活性的达玛烷型人参皂甙Ｒｅ的同核、异核二维化学位移相关谱和相敏双量子滤波二维相关谱，由此归属了人参皂甙Ｒｅ的氢谱，测定了Ｒｅ的质子偶合常数。     

用于远红外FEL的直线加速器物理模拟计算

波长在２００μｍ附近的自由电子激光对电子束品质有特别要求，不仅要求较长的束流微脉冲，而且对流强、能散度以及束流参数对加速器噪声的稳定性等都有很高的要求。我们采用ＰＡＲＭＥＬＡ程序，对一台由１０８ＭＨｚ分频预聚束器、９腔１３００ＭＨｚ聚束加速段和９腔１３００ＭＨｚ加速段组成的加速器进行了大量模拟计算，得到了满足ＦＥＬ要求的物理设计方案和对加速器各部件稳定性的要求指标。     

行波偏转器前置短磁聚焦条纹变像管理论设计与实验研究

条纹变像管因其超高时间分辨特性而成为实现皮秒至飞秒量级时间分辨的重要测量仪器.本文设计了一种同时兼顾高时空分辨的行波偏转器前置短磁聚焦条纹变像管.该管型通过减小电子渡越时间以抑制空间电荷效应、采用偏转器前置以及行波偏转方式提高偏转灵敏度,实现整管时空分辨率的大幅提升.利用CST微波工作室有限元法数值计算条纹变像管行波偏转器的通频带宽、偏转灵敏度,结果表明:本设计中的行波偏转器因其较高的通频带宽特性实现了偏转器上的电磁波相速度在很宽频率范围内与电子轴向群速度匹配,产生更有效偏转.利用CST粒子工作室模拟追踪光电子的运行轨迹,通过最佳像面上的时间调制传递函数和空间调制传递函数,计算得到其理论时间分辨率可达220 fs,空间分辨率高于100 lp/mm.同时根据像差定义给出追踪实际电子轨迹的像差计算方法,实现对变像管成像质量评价.最后利用紫外灯对其进行静态测试,获得静态空间分辨率优于35 lp/mm的结果.     

Acousto-Optic Deflector with a High Diffraction Efficiency and Wide Angular Scanning Range

A new acousto-optic deflector with a wide angular scanning range and a high diffraction efficiency has been studied. The device uses an additional deflector, which allows the angle of incidence of the input beam to be adjusted in order to fulfill the Bragg phase–matching condition over the entire scanning range of the main deflector. The characteristics of an anisotropic two-crystal deflector based on paratellurite crystals have been measured. It has been established experimentally that the operating bandwidth of the device is 32 MHz for a diffraction coefficient no less than 90%, which determines a light beam scanning angle of 50 mrad.     

用于声光相关/卷积器的双向声光偏转器

本文提出了用于声光相关／卷积器的双向声光偏转器的设计、制备和测试结果．两个通道的中心频率均为175MHz，带宽70MHz，衍射效率30％，渡越时间7μs．已在空间相干器时间相干器系统中得到应用．     

梯形双梁结构超导偏转腔的优化设计北大核心CSCD

双梁结构超导偏转腔可对带电粒子束进行快速的偏转或旋转,具有紧凑、高效的特性,在超导自由电子激光、高能粒子对撞机等加速器装置中具有广泛的应用前景。该类型超导腔设计研究的一个重点是双梁形状的选择和尺寸的优化。针对中国科学院高能物理研究所提议建设的、基于超导直线加速器的X射线自由电子激光装置,采用CST MWS,CST PS,COMSOL,ANSYS等软件仿真手段,结合理论分析,完成了一款双梁形状为梯形的超导偏转腔的优化设计。该梯形双梁结构偏转腔具有良好的电磁和机械性能,同时,腔的尺寸更加紧凑,加工难度也有所降低。     

Acousto-optic deflector of depolarized laser radiation

An original acousto-optic deflector is based on the anisotropic diffraction in the paratellurite crystal. The deflector is characterized by a relatively high diffraction efficiency for depolarized laser radiation. The deflector consists of two sequential acousto-optic cells. Each cell deflects one of the orthogonally polarized components of the originally depolarized radiation. The first and second cells scan the low- and highfrequency parts of the angular interval, respectively. The simultaneous and independent operation of the cells makes it possible to use the entire optical (laser) power. A frequency band of 32 MHz is almost reached for depolarized radiation with a wavelength of 1.06 µm and the absolute angular interval is 50 mrad at a total efficiency of no less than 70%.     

Bunch length measurement using a traveling wave RF deflector

RF deflectors can be used for bunch length measurement with high resolution. This paper describes a completed S-band traveling wave RF deflector and the bunch length measurement of the electron beam produced by the photocathode RF gun of the Shanghai DUV-FEL facility. This is the first time that such a transverse RF deflector has been developed and used to measure the bunch length of picosecond order in China. The deflector's VSWR is 1.06, the whole attenuation 0.5 dB, and the bandwidth 4.77 MHz for VSWR less than 1.1. With a laser pulse width of 8.5 ps, beam energy of 4.2 MeV, and bunch charge of 0.64 nC, the bunch lengths for different RF input power into the deflector were measured, and an averaged rms bunch length of 5.25 ps was obtained. A YAG crystal is used as a screen downstream of the deflector, with the calibrated value of 1 pix = 136 μm.     

声光偏转效应在相干光检测的应用

为使现代电子侦察技术能适应信号密集、宽频谱、大动态的电磁环境, 提出了一种基于声光偏转器实现相关光信号处理的方法, 分析了射频信号频率变化与布拉格衍射角的关系, 讨论了声光偏转效应对信号频率的空间滤波特性; 在理论分析的基础上, 构建了在可见光范围内实现声光偏转的相干光信号探测的实验系统, 并通过计算机仿真对比, 验证了这种方法的可行性。实验表明, 采用波长为630 nm的单频激光, 带宽为200 MHz的声光偏转器, 其频率分辨率优于1 MHz, 频率信号的空间分离效果明显, 接收灵敏度和信噪比得到改善。     

Extension of the angular scanning range of the acousto-optic deflector with a two-element phased-array piezoelectric transducer

The acousto-optic deflector with a two-element phased-array piezoelectric transducer is studied at an almost limiting diffraction efficiency. Significant broadening of the working acoustic frequency band (and angular scanning range) relative to the well-studied low-efficiency regime is theoretically predicted and experimentally demonstrated. For the off-axial deflector based on paratellurite (TeO₂), a radiation wavelength of 1.06 μm, and a two-element transducer with a total length of 6 mm, the working frequency band is 17–48 MHz (with the lower frequency determined by the electromechanical properties of the transducer) at an efficiency of no less than 94% of the maximum value.     

Broad band Bragg deflector for optical waveguides on silicon substrates

Technical solutions are described which allow the 500 MHz acousto-optical Bragg deflector integrated onto a silicon substrate to have a good performance and quite high deflection efficiency. This is achieved by diminishing the influence of acoustic propagation losses. As a consequence, is it possible to implement a large bandwidth acousto-optical rf spectrum analyser using fully planar technology.     

声光偏转器扫描飞秒激光的时间色散补偿

研究了声光偏转器(AOD)扫描飞秒激光的时间色散效应及补偿方案.在800nm波长处，单个AOD引入的群延时色散(GDD)可达～9300fs².在深入分析AOD和棱镜角色散原理的基础上，提出了用色散棱镜预补偿AOD对飞秒脉冲的时间色散，并进行了实验证实.在AOD中心频率处(70MHz)，将398fs的脉冲压缩到122fs，且整个带宽范围内(50MHz—90MHz)脉宽变化范围为120fs—180fs.这表明该方案用于AOD扫描飞秒激光时进行时间色散补偿是非常有效的. 关键词： 飞秒激光 声光偏转器 时间色散 脉冲压缩     

Acousto-optic deflector based on a paratellurite crystal using broadband acoustic adhesive contact

A broadband acoustic matching of a piezoelectric transducer made of a lithium niobate crystal with an acousto-optic TeO₂ crystal has been studied. The transducer is acoustically attached to the crystal by the method of adhesive contact. The experimental method of creating a piezoelectric transducer with an acoustic matching layer from a tin film is developed. The conditions of the optimal technological regime when applying the matching layer are determined. The results of the research are used in creating a broadband high-performance deflector with a central ultrasound frequency of 37 MHz, with the frequency band scanning more than 30 MHz, and a diffraction efficiency of about 90% at a wavelength of 1.06 μm.