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The filter made up of two gratings performs as a two-dimensional non-spatial filtering. This paper reports that the volume Bragg gratings are fabricated by interfering two collimated coherent laser beams in photopolymer. Diffraction efficiency of a single grating is up to 78% in Bragg's condition, then a two-dimensional non-spatial filter, which consists of two volume Bragg gratings and a half-wave plate, enables the laser beam filtered in two dimensions with the diffraction efficiency of 54%. The Bragg's condition and effect of polarisation on performances of the two-dimension filter are also discussed. 相似文献
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<正>Diffraction efficiency of volume Bragg grating,whose period is in the same order as the incident wavelength, is related to the polarization direction of the incident linear polarized beam.When two linearly polarized recording beams with the same polarization direction are used for recording volume Bragg gratings in a photopolymer with diffusion amplification,the azimuth of polarization of the reconstruction beam influences the diffraction efficiency of the grating.When the probe beam is linearly polarized and oriented orthogonally to the grating vectors,the±1-order diffraction beams are also linearly polarized with polarization direction parallel to that of the probe beam.According to the results,a two-dimensional nonspatial optical filter consisting of the volume Bragg gratings would achieve significantly higher efficiency. 相似文献
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《MATTERINTERACTIONS》[1]教材以一种新的理念于众多物理导论教材中脱颖而出。其重要特点就是从基本原理而不是推理(次级)公式开始分析,通过构建和分析弹簧—质点简谐振动力学模型,以能量为桥梁从力学自然过渡到热学(认为热学不应该作为物理导论的一个独立章节)以及近代物理,并用表面电荷将电学和电路进行统一;而计算技术是使之能在教学中完美实施的重要支撑。本文阐明了计算机与理论和实验一起已经并列成为物理导论课程(乃至物理学)的第三大支柱的意义以及作用,并给出了相应的例子。其突破传统的理念和模式希望能给国内高校物理教学改革一定的启迪。 相似文献
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建设了国内首门大学物理实验MOOC并撰写了配套教材.实验MOOC及教材的建设应立足于信息技术与教育教学深度融合大环境下的新型教学培养模式,遵循科学性、多元性、动态性以及实用性的原则.以此建设的大学物理实验MOOC以虚拟仿真实验、自主实验以及远程控制实验为主体,以案例式教学为特征,教学采取对于给定实验目标(每个案例相互独立),以物理建模为主线,充分挖掘实验思想以及关注模型成立条件等方法.教材撰写以同样理念为指导,有机整合课程平台内容,同时在编排形式上进行了改革.如正文中对测量模型及讨论的套色加框,空白宽边中的提纲挚领,重点醒目突出;余留的空白宽边可使学生与教材互动,有助于学习效率提升. 相似文献
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