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对时间积分声光相关器的原理进行了理论分析,通过实验得到了叠加在包络上的相关峰波形,为了对其进行修正,引入了后处理电路,最后得到了比较理想的相关峰波形。 相似文献
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1 Introduction High performance opticalswitchingtechnologiesarecurrentlyofenormousinterestforthecommunicationsindustry .Todatemanytechnologieshave producedhigh performancecharacteristics[1,2 ] .Therequirementforthesuccessfultechnologieswillbelowinsertionlo… 相似文献
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1 Introduction Thefiberdevicesbasedonfiberfusednullcouplerarerecentlyofgreatinterest.All fiberacousto opticswitch[1] ,tunableopticalfilter[2 ] ,opticaladd dropmultiplexer (OADM ) [3] andfiberpolarizer[4 ] havebeenreported .Foralltheseapplications ,nullcouplerwithlow… 相似文献
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Florence Burdin Pascal Guiraud Anne‐Marie Wilhelm Henri Delmas 《Particle & Particle Systems Characterization》2002,19(2):73-83
Knowledge of the acoustic cavitation cloud would be useful for improving ultrasound reactor design. Among the characterisation techniques, few are adapted to bubble investigations in an intense ultrasound field. Some problems raised by these measurements result from interactions between the acoustic pressure wave and the measuring light wave. This paper reports the implementation of the laser diffraction technique to determine the size and volume concentration of bubbles generated by a dipping horn operating at 20 kHz. Measurements were performed with a Malvern 2600 instrument. The size distribution, deduced from the diffraction pattern scattered by the bubble cloud crossed by a laser beam, is disturbed by the acoustic pressure wave involving deviation of a light beam at low diffusion angles (acousto‐optic effect). A bubble size correction procedure based on the subtraction of the light energy due to the ultrasound wave is described. The size measurements, and thus the correction procedure, were validated by a second laser technique based on a different measuring principle: phase Doppler interferometry. The measurement reliability was further confirmed by an original application of laser diffraction based on measurements performed just after sonication. These three methods lead to a mean bubble size (Sauter mean diameter) of about 10 μm at a high ultrasound power input. Concerning the void fraction, only measurements achieved after sonication and by laser diffraction predict a correct estimation of this parameter. 相似文献
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偏振无关的楔型光隔离器插入损耗与反向隔离度分析 总被引:3,自引:1,他引:2
在高斯光束传输理论基础上,推导出求解偏振无关楔型光隔离器插入损耗与反向隔离度的数学解析表达式;得出了采用不同材料隔离器的插入损耗,反向隔离度与双折射晶体倾斜角度及双折射晶体和旋转晶体间距的关系曲线,分析了影响光隔离器插入损耗,反向隔离度的因素,实际测量结果与理论分析相吻合。 相似文献
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声光双稳系统的混沌同步 总被引:6,自引:0,他引:6
首先给出布拉格型声光双稳系统耦合驱动的混沌同步化方案,用最大条件Lyapunov指数分析方法得出耦合驱动下系统混沌输出同步化条件,发现通过适当比例的耦合驱动可以使两组混沌系统达到同步的混沌输出。分析此混沌同步化方案可以抵抗噪声的干扰,并且在两系统出现偏差时仍可以实现混沌同步,找到了实用的单变量延时微分系统非Pecora-Carroll规则的混沌同步化方案。最后做了实验验证。 相似文献
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高动态范围声光接收机 总被引:1,自引:0,他引:1
介绍了一种高动态范围声光接收机,这种接收机具备实现宽带射频信号幅度,频率和相位的信道比探测能力,该接收机在0.6328μm激光器的工作条件下(1.0mW),声光布拉格盒在50mW射频信号区动下,在140MHz的中心频率上20MHdisplay status 相似文献
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C. Cuadrado‐Laborde A. Díez J.L. Cruz M.V. Andrs 《Laser \u0026amp; Photonics Reviews》2011,5(3):404-421
The interest in all‐fiber lasers is stimulated by the inherent advantages they have over bulk lasers in aspects such as heat dissipation and robustness. The performance of Q‐switched and modelocked fiber lasers can benefit enormously from the development of all‐fiber configurations. A fiber laser with strictly all‐fiber components can fulfil the requirements of mechanical stability, low maintenance, enhanced power efficiency, simplified assembly process, and low cost. In this framework, recent developments infiber acousto‐optic devices are reviewed that have demonstrated new possibilities for actively Q‐switched distributed feedback fiber lasers, modelocking lasers and doubly active Q‐switched modelocked lasers. The aim is to demonstrate the great potential of infiber devices for the active control of different types of fiber lasers. 相似文献
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声光可调谐滤波器多波长同时滤波的特性 总被引:2,自引:0,他引:2
集成光学声光可调谐滤波器 (AOTF)有很多优点 ,特别是它可以同时滤出多个波长 ,因此在波分复用(WDM)光纤通信网络中有重要应用。针对其这种特性 ,运用耦合模理论 ,导出了同时存在两束声波时的严格的耦合模方程。在此基础上 ,得到滤波特性的数值解 ,分析了多波长同时运用时 ,滤波器的主峰强度、中心波长和 3dB带宽随时间的波动 ,同时也分析了当信道间隔较小时滤波特性失真严重、噪声较高的原因。在分析了共线型声光可调谐滤波器多波长同时运用所存在缺点的基础上 ,提出利用准共线模转换器来改善声光可调谐滤波器多波长同时运用的性能。 相似文献
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