Mixing and detection of microwave signals in fibre-opticelectrostrictive sensor

The nonlinear strain-polarisation relationship in electrostrictive ceramics is exploited to demonstrate, for the first time, detection and mixing of microwave signals in a fibre-optic electrostrictive sensor. The nonlinear electrostrictive transducer mixes the microwave signal with a signal from a local oscillator, and the resulting strain at the intermediate frequency is detected with a fibre-optic interferometer. The sensor demonstrated approximately flat response in the microwave regime (up to 20 GHz) with a resolution of 5×10^-6 V/√ Hz     

压电／电致伸缩材料及驱动器的新技术与应用

压电／电致伸缩驱动器是一种广泛使用的驱动器,文章概括总结了几种压电／电致伸缩新材料的发展方向,同时还介绍了几种新型驱动模式和超声电机的研究动态,并对压电／电致伸缩驱动器的发展前景予以展望。     

压电陶瓷式执行器的动态特性的改善研究

针对电压陶瓷微位移执行器动态响应慢的问题进行了研究,提出用数字ＰＩＤ方法加以解决,并研制出一套实用控制系统,其中,研制出一种可微机控制的精密高压调节器,与单片机数字系统相配合,形成了一个完整的、数字－模拟电路结合的控制系统,用于实现压电陶瓷微位移器动态性能的改善。实验表明,该控制系统简单、可靠、实用。所提出的ＰＩＤ方法对压电陶瓷微位移执行器的动态特性有明显的改善。     

Mechanisms for self-focusing in optical glasses

The relative contributions of the Kerr, electrostrictive, and thermal effects to the self-focusing thresholds of borosilicate crown glass, fused silica, and dense flint glass have been estimated from an analysis of damage-threshold data for linearly polarized and circularly polarized radiation. The measurements were made with a Nd:glass laser operating in the TEM00mode with a temporal pulsewidth of 25 ns. The Kerr effect appears to be the largest effect. The thermal effect is also significant. The electrostrictive effect is smallest. Reasonable values of the absorption coefficient are calculated from the thermal contribution. The results are in qualitative agreement with the work of others.     

Electric Actuation of Nanostructured Thermoplastic Elastomer Gels with Ultralarge Electrostriction Coefficients

Electrostriction facilitates the electric field‐stimulated mechanical actuation of dielectric materials. This work demonstrates that introduction of dielectric mismatched nanodomains to a dielectric elastomer results in an unexpected ultralarge electrostriction coefficient, enabling a large electromechanical strain response at a low electric field. This strong electrostrictive effect is attributed to the development of an inhomogeneous electric field across the film thickness due to the high density of interfaces between dielectric mismatched periodic nanoscale domains. The periodic nanostructure of the nanostructured gel also makes it possible to measure the true electromechanical strain from the dimensional change monitored via in situ synchrotron small angle X‐ray scattering. The work offers a promising pathway to design novel high performance dielectric elastomers as well as to understand the underlying operational mechanism of nanostructured multiphase electrostrictive systems.     

电致伸缩材料研究的新进展

简要地综述电致伸缩材料在合成、制备和离子掺杂改性方面研究的新进展。介绍了电致伸缩材料发展现状。     

乳浊液非线性光学性质研究

本文利用单光束扫描法，对乳浊液中产生非线性光学现象的两种起源进行了研究，从而确定了它们各自对折射率变化的贡献，并对油／水和水／油两种乳浊液非线性光学性质进行了比较。     

电致伸缩陶瓷微位移器非线性的数值方法补偿

本文通过对电致伸缩陶瓷材料的非线性进行分析。找到了补偿电致伸缩陶瓷非线性的数值方法，并对不同回程大小的电滞回线进行了分段处理，使补偿结果更为精确。     

超精密微调架的设计

本文介绍了一种由机械粗调和压电微调组合而成的复合型超精密微调架,并着重介绍了由电致伸缩陶瓷微位移器和柔性铰链或簧片组合成亚微米级精度微调机构的设计。     

驱动器用陶瓷材料发展与展望

叙述了适用于制造驱动器的几种陶瓷材料,即压电陶瓷、电致伸缩陶瓷、相转变（反铁电-铁电）陶瓷和弛豫基铁电单晶材料,并对它们各自的优缺点及特性作了简单的评述,同时展望了它们在驱动器领域的应用前景。     

显微数字散斑相关测量新型薄膜的力学性能

利用显微数字散斑相关方法(DSCM)对新型高分子薄膜材料力学性能进行了研究。通过实时获取高精度的变形位移场,得到应变场与力学性能之间的关系,实现了新型高分子薄膜的力学性能分析。利用该方法对聚酰亚胺-二氧化硅合成薄膜进行面内位移测量,由薄膜的应力-应变曲线完成了薄膜材料的弹性模量测量;将离面位移的测量转化为面内位移的测量,对聚氨酯-钛酸钡复合高分子材料的电致伸缩应变进行了测量,从而获得电致伸缩系数,实现了材料的电致伸缩性能分析。采用亚像素搜索和曲面拟合相结合的方法进行数据处理,并对结果进行了分析。研究结果表明,数字散斑相关方法为研究新型薄膜材料动静态力学性能与物理性能提供了一种有效的、可行的方法。     

Generation of surface acoustic waves using the electrostrictive effect

Surface acoustic waves have been generated and detected on a biased electrostrictive substrate. A delay line with an insertion loss of 26 dB at 77 K has been constructed on strontium titanate. The temperature and electric-field dependence of the insertion loss are given.     

用单光束扫描法测量球状电介质悬浮液的非线性折射率

利用单光束扫描法研究了球状电介质悬浮液的非线性光学性质，对直径为０．０５９μｍ，浓度为２．５％的聚苯乙烯悬浮液的非线性光学系数。。进行了测量，给出ｎ２值为４．３×１０－９ｃｍ２／Ｗ．从实验中得出这种悬浮液中。。引起的折射率变化远大于热效应弓；起的折射率变化．     

Nonstationary fluid dynamics under exposure to nanosecond voltage pulses

A numerical analysis of the liquid motion in a spherical capacitor under the applied voltage pulse with a duration of several nanoseconds and a peak value to 300 kV is performed. A system of hydrodynamics equations written in the general form in the spherical coordinate system and the Tait equation of state are used to simulate the liquid motion. The electrostrictive pressure is calculated for a liquid in the form of a dipole dielectric.     

光束相干驱动声子场提高SBS相位共轭保真度稳定性

光束相干引起的电致伸缩能驱动声子波，从而能加强受激布里渊散射（ＳＢＳ），提高相位共轭保真度稳定性。对折反池结构，采用２ｎｓ陡前沿的脉冲光泵浦，将双级钕玻璃放大器和ＳＢＳ池作为整体，测量了其相位共轭保真度。观测到输出激光的能量远场空间分布和相位共轭保真度稳定性在光束夹角θ５ｍｒａｄ时明显优于θ＞３０ｍｒａｄ。     

波导法兰连接的无源互调分析与测量

在卫星通信系统中,非铁磁性微波无源器件的无源互调(PIM)问题非常严重,产生PIM的根源在于天线、波导法兰等无源器件的非线性效应,例如场发射、量子隧穿、热电子发射、电致伸缩、微放电等[1]。文中通过对波导法兰无源互调模型的分析和测量,得出波导间接触压力越大,各阶PIM越小;PIM阶数越高,载波功率之比对其影响越大。     

Electromagnetic field photonic sensors

In this paper, we review the different configurations proposed for electromagnetic field optical sensing. Intrinsic and extrinsic optical fiber sensors for electric and magnetic field measurement are examined, including those realized jacketing the fiber by magnetostrictive, conductive, electrochromic and polymeric materials and those measuring induced strain by magnetostrictive, electrostrictive and piezoelectric transducers. Extrinsic optical fiber sensors exploiting magneto-optic, electro-optic and Joule effects are also presented.Moreover, integrated optical electric and magnetic field sensors in which microwave signal provided by an antenna modulates the optical signal generated by an optical source are reviewed. Finally, active and coupled resonators based on electric field sensors are investigated.     

Stimulated Brillouin scattering as a parametric interaction

In the stimulated Brillouin scattering of an intense laser beam, a forward-traveling coherent acoustic wave and a backward-traveling electromagnetic wave are produced. This interaction is studied from the coupled mode approach and shown to be describable as a parametric interaction. An inherent instability of this particular interaction is discussed. Frequencies of the interacting waves are calculated for quartz and cadmium sulfide. The non-linearity is shown to be due to the electrostrictive and photoelastic properties of the medium. By expressing the coupling coefficient as a tensor of rank four, selection rules for the interaction in isotropic and certain anisotropic media are derived. Finally the experimental approach for detection of the acoustic wave is discussed.     

电致伸缩/压电微尺度智能结构的伽辽金方法

在微纳米尺寸的智能结构中,电致伸缩(PMN-PT)/压电(PZT)材料有着广泛的应用前景。本文基于哈密顿变分原理,得到PMN-PT/PZT微尺度梁的智能结构系统运动方程的弱形式。采用以B样条函数为基函数的有限维近似的伽辽金方法,建立起该系统的状态方程。对于由PMN-PT的诱导应变与电场成双曲唯象关系引起的非线性问题,采用线性化输出方法,获得作动诱导应变与控制器输出的线性关系。以PZT做传感器、PMN-PT做作动器的梁系统的控制算例表明了方法的正确性与有效性。此方法可进一步推广到更为复杂的智能结构系统中。     

Transverse Brillouin Effect Produced by Electrostriction in Optical Fibers and Its Impact on Soliton Transmission Systems

Large radial gradient of light intensity in single-mode fibers leads to excitation of transverse acoustic waves through electrostriction mechanism. The nanosecond range for the acoustic effect introduces a time-dependent index evolution for the optical pulses following and results in an additional temporal shift. The dynamic frequency shift of optical pulses in optical fibers is evaluated by a time-domain resolution technique using copropagated pump and probe signals arrangement. Complete electrostrictive response measurements including excitation of pure radial and mixed torsional–radial acoustic modes are presented. In a second time, the acoustic effect is incorporated in the nonlinear Schrödinger equation as a perturbative term. We have investigated the evolution of timing jitter, taking into account both the Gordon–Haus and the acoustic interaction contributions for different dispersion management soliton system configurations in order to evaluate the induced penalties.