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．     

Some properties of TeO2 light deflectors with small interaction length

The possibilities of shortening the interaction length of TeO₂ abnormal light deflectors for a wavelength of 6328 Å are investigated in this paper. It is shown by simple theoretical considerations and also experimentally that the interaction length can be as small as 3–5 mm. Some experimental results are also given which show that the performance of such deflectors remains unchanged.     

超越曲面电极结构电光偏转器研究

采用有限元法对几种不同电极结构下电光偏转器的电场分布进行研究.设计出一种具有较大偏转角度的超越曲面电极结构电光偏转器，与圆柱电极结构和双曲面电极结构电光偏转器的性能对比，可知此种电光偏转器的偏转角度更大，电场梯度线性度更高.     

畴反转结构片状集成4×4电光开关的设计与仿真

基于铁电体畴反转结构的电光偏转特性,设计了一种片状集成的4×4电光开关,其由四个结构相同的半抛物和四个抛物形微小偏转器集成构成.通过优化抛物形偏转器结构,给出了电光开关的设计参量,电光开关性能通过光束传播法进行仿真模拟,仿真结果表明该开关切实可行.实际应用中,系统误差可以通过电场调节补偿,使光路准确交换.该片状电光开关的整体尺寸为48 mm×2.2 mm×0.5 mm(长×宽×高),最大使用电场约13.73 V/μm,适用于高速交换的光互连系统.     

Nonmechanical image rotation with an acousto-optic dove prism

We report what we believe to be the first method for nonmechanical and programmable image rotation. The method uses a pair of crossed acousto-optic beam deflectors and a polygon mirror to emulate the mechanical dove prism. It is capable of fast (of the order of microseconds) image rotation to an arbitrary angle in a programmable manner. An experimental result that proves the concept is provided.     

畴反转结构片状集成4×4电光开关的设计与仿真

基于铁电体畴反转结构的电光偏转特性,设计了一种片状集成的4×4电光开关,其由四个结构相同的半抛物和四个抛物形微小偏转器集成构成.通过优化抛物形偏转器结构,给出了电光开关的设计参量,电光开关性能通过光束传播法进行仿真模拟,仿真结果表明该开关切实可行.实际应用中,系统误差可以通过电场调节补偿,使光路准确交换.该片状电光开关的整体尺寸为48 mm×2.2mm×0.5 mm(长×宽×高),最大使用电场约13.73 V/μm,适用于高速交换的光互连系统.     

Frequency and angular bandwidth of acousto-optic deflectors with ultrasonic walk-off

In the paper, bandwidth parameters of acousto-optical deflectors (AODs) are analyzed from the point of view of acoustical anisotropy. Equations for bandwidth and central frequency of AOD are derived for arbitrary propagation direction of ultrasound in optically uniaxial crystals. The phenomenon of bandwidth shift due to phase mismatch at the central frequency is studied theoretically and verified experimentally.     

Calibration of optical tweezers based on acousto-optic deflector and field programmable gate array

Accurate calibrations of stiffness and position are crucial to the quantitative measurement with optical tweezers. In this paper, we present a new calibration scheme for optical tweezers including stiffness and position calibrations. In our system, acousto-optic deflectors (AODs) are used as laser beam manipulating component. The AODs are controlled by a field programmable gate array (FPGA) connected to a computer using universal serial bus (USB) communication mode. Our results agree well with the present theory and other experimental results.     

On the transition from Weyl to Ricci focusing

Using the weak-field approximation, we show that the Weyl focusing of rays in a beam of light which passes around a number of spherical deflectors may be approximated by the Ricci focusing of the beam due to the enclosed mass.     

Performance limits of acoustooptic light deflectors due to thermal effects

Applied Physics A - Transducer conversion losses as well as acoustic and optic attenuation in solidstate acoustooptic light deflectors are responsible for temperature and stress fields which lead...     

Some aspects in accelerator structure studies at SLAC

Recent progress in the accelerator structure studies at SLAC is reported. This paper covers the room temperature accelerator structures for the ILC e+/e- sources; RF structures for some photon science projects including RF deffectors and the LCLS RF gun; the high gradient accelerator R&D in a global CLIC collaboration for the future multi-TeV linear colliders.     

Optical scanner - light deflection using computer-generated diffractive elements

Some ideas are presented about optical deflectors. Using computers to form generalized diffractive elements can be used to advantage. Three unique features can be incorporated in the elements. These are: 1) convenient selection of their geometrical shape, 2) changes in speed and direction of the deflected light beam, and 3) variations in focal power. Some practical realizations are discussed.     

3D simulation of the ion-beam transport in bending magnets and electrostatic deflectors

The equations and algorithms for calculating the charged-particle-beam dynamics in bending magnets and electrostatic deflectors, which are used in the ion-beam transport lines and spectrometers, are presented. Calculations of the electromagnetic field 3D maps are illustrated. The value of the electromagnetic-field nonlinearities and their effect on the particle dynamics are analyzed. The simulation of the ion dynamics in the axial injection beam line of the DC-280 cyclotron and GALS spectrometer created at the JINR Laboratory of Nuclear Reactions (FLNR) is described.     

Low power light deflector on domain structure in (Y,Ca)3(Fe,Ge)5O12

The domain structures in (Y, Ca)₃(Fe, Ge)₅O₁₂ epitaxial garnet films were investigated as a function of various directions and the intensity of an applied magnetic field. The cubic anisotropy has a strong influence on the domain structure properties in these samples. Very large changes of the stripe domains directions could be obtained by applying a low magnetic field (about 1 [Oe]). The investigated domain structure properties could be used for the light deflectors of a new type, based on the light diffraction.     

Three-dimensional vision with dual acousto-optic deflection encoding

We report a new method of sensing a three-dimensional (3D) object surface with an arbitrary geometric shape. In this approach, the first-order beams diffracted from two acousto-optic deflectors (AODs) interfere with each other to form a spatial carrier that is used to encode the depth information from the 3D object surface. A direct digital synthesizer is utilized to control two AODs to generate sequentially spatial carriers with different spatial frequencies so that a modified temporal phase-unwrapping technique can be applied for decoding the shape information of the test surface. Preliminary experimental results are presented to demonstrate the effectiveness of this method.     

The aberration theory of a combined electron focusing–deflection system with a rotating deflection field following the rotation of the electrons

A new type of combined magnetic focusing–electrostatic deflection systems whose orientation of deflection field is rotated synchronously with the beam electrons is proposed. This rotation deflection field can be formed by twistification of tube wall electrode (TWE) deflectors. Formulae are derived for the first-order optical properties, third-order geometrical aberrations and first-order chromatic aberrations of this system. A program was written in FORTRAN for numerical computation. An example is given; the computation results show that compared to the conventional systems, the proposed new system has lower deflection aberration coefficients.     

多级聚焦-偏转复合系统的相对论象差理论

本文在文献[1]的基础上,导出了聚焦-偏转复合系统的相对论一级色差及另一形式的相对论三级几何象差公式,得出了各种象差系数的明显公式,应用上述理论,本文讨论了多级电-磁的偏转复合系统中象差的叠加问题。 关键词：     

低密度聚乙烯热压成型过程中的空间电荷

借助开路热刺激放电(TSD)电流及原位实时电荷TSD和电荷等温衰减测量，研究了低密度聚乙烯(LDPE)在热压成型过程中所产生的空间电荷特性.结果表明具有良好室温稳定性的成型电荷被束缚在两类陷阱能级中：浅阱和深阱，其陷阱中心深度分别约为0.92eV和1.31eV.初步的分析进一步表明了它们应该分别位于试样的表层和体内，为近表面陷阱和体陷阱. 关键词： 低密度聚乙烯(LDPE) 热压成型 空间电荷 热刺激放电(TSD)     

Adsorption of polymer chains by disordered traps

We study the adsorption cross-over of ideal polymer chains in an environment of disordered traps. Starting from the assumption of an optimal cluster size of traps (optimal fluctuation method) we derive a general scaling form of the free energy function for arbitrary spatial dimensions. For small concentrations of traps we find a cross-over from localized (adsorbed) behavior to delocalized behavior depending on the chain's length and on the depth of the traps; this is connected with the non-monotonic behavior of the chain's extension. In terms of the free energy of the chain this cross-over resembles a first order transition scenario, the chain gets localized at many traps at once. Received 18 November 1998     

光漏斗聚光定向传光中央接收太阳能集热系统

提出了一种新型中央接收式太阳能高温集热系统,介绍了系统的运行原理,分析了系统的热效率影响因素。这个新型的太阳能高温集热系统具有如下特点:可将多个光漏斗和偏光器组成一个太阳能聚光器阵列,每个聚光器都能将低能流密度的太阳光束会聚成高能流密度的平行光束,并由偏光器传送到中央接收器,于是中央接收器可获得很高的太阳光照射能流,转化为热能后将产生很高的温度,从而实现太阳光高温聚能。本系统的中央接收器无需建在高塔上,节省了建设费用,而且所有光漏斗跟踪太阳的方式相同,控制策略简单,定向偏光器的出光方向设定后可以固定不变,因而使整个系统结构简单,技术上易于实现。