共查询到18条相似文献,搜索用时 62 毫秒
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本文根据全息学基本原理,应用光的干涉,衍射理论详细描述了曲面全息元件的成象特性。用位相比较法导出了一套曲面全息光学元件的成象公式及焦距和各项放大倍率计算公式。 相似文献
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光纤全息散斑干涉计量 总被引:1,自引:1,他引:0
脉冲激光经光导纤维传输后,其偏振性变化为随机分布,相干性有所降低,但它用在全息干涉计量中却有突出的优点,对于涉条纹的形成和清晰度没有影响。经常使用的光纤散斑全息干涉系统有两种类型:一种是只用传光束形成物光,参考光,此种系统形成的全息象清晰度有所下降,但做全息干涉计量时对条纹的衬比度和清晰度没有任何影响.另一种类型是物光和参考光都是用光导纤维传输,然后用光纤传象束将物体的象进行传输,再用透镜将其成象在底片上,做双曝光全息干涉时则形成全息散斑干涉计量,用全息方法再现时干涉图类似“杨氏”条纹。本文对上述两种系统,结合实验结果、分三种情况进行了研究。文章共分为三个部分:(一)引言;(二)散斑全息干涉计量;(三)结论。 相似文献
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利用数值求解含时薛定谔方程和强场近似理论研究了反向旋转双色椭偏光场中氩原子隧穿电离电子的干涉.固定两脉冲的椭偏率均为0.3,当两椭偏场的相对相位为0.25π时,光电子动量谱中周期内干涉、叉状全息干涉和弧形全息干涉相互重叠.当两椭偏场的相对相位为0时,光电子动量谱中弧形全息干涉消除,并且周期内干涉和叉状全息干涉被彻底分离到动量谱的左右部分,从而得到一个在空间上独立的叉状全息干涉条纹.进一步研究表明,通过改变两椭偏光场的椭偏率还可以增强或抑制该独立叉状全息干涉条纹.这为干涉条纹的控制和分离提供了一个有效的手段,同时也有利于从全息干涉条纹中提取靶材结构信息和电子超快动力学信息. 相似文献
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电子学全息干涉术用于温度场测量 总被引:11,自引:4,他引:7
探讨了用电子学全息干涉术(双称数字全息干涉术)测量温度场分布及其变化的可行性,利用所设计的全息干涉实验光路,对一电烙铁头部周围温度场分布进行了实时全息记录,进而利用一维快速傅里叶变换及数字滤波处理再现出了反映温度场分布的全息干涉条纹图样,实验结果表明,与传统的光学全息干涉术相比,电子学全息干涉术借助于高分辨率CCD记录及高速计算机数字处理技术,从而可实现光学全息图的数字化记录、存储和重现。同时,利用再现物场相位倍增原理还可实现对干涉条纹数目的倍增,或利用物场相位分布的直接计算精确获取任意两点间的相位差,从而提高测量精度。此外,由于能够在不改变光路的前提下以较高的重复频率完成光学全息图的记录,电子学全息干涉术可以用于记录三维物场的变化并接近实时地再现和测量三维物场的变化规律,因此是一种极有发展前途的新型实时全息干涉计量技术。 相似文献
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在实时全息干涉计量实验中,当试件负荷甚大时,干涉条纹中会出现一些阴影区,它们在试件破裂过程中起重要作用。当负荷接近试件断裂强度时,可清晰看到并记录下阴影区的延伸、分叉、扩展直至试件破裂的过程。这些阴影区实际上就是几何光学中的焦散线现象。应用此现象可以计算应力强度因子。介绍了在寻找全息干涉条纹与应力强度因子之间关系所作的研究,导出了干涉条纹最大值与应力强度因子之间的定量关系式。从而,为使用全息法与焦散线法相结合的检测方法提供了定量计算的基础。 相似文献
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A. M. Lyalikov 《Optics and Spectroscopy》2006,101(1):162-167
The possibility of studying phase objects by reverse shearing interferometry with high measurement sensitivity is demonstrated. Phase objects are studied in two stages. In the first stage, holographic reverse shear interferograms are measured with and without an object under nonlinear conditions with tuning to frequent reference fringes. In the next stage, these interferograms are optically processed to obtain two interference patterns. The behavior of the interference fringes is the same as in the case of conventional double-beam interferometry with a standard reference wave. The increase in the measurement sensitivity in the thus-obtained interference patterns is due to the use of higher diffraction orders reconstructed from the holographic interferograms. A possibility of controlling the width of interference fringes is considered. The results of experimental approval of this technique are presented. 相似文献
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用实时全息术研究低速变化过程的一种简易系统 总被引:7,自引:3,他引:4
研制了一种用于研究物体低速过程的简易系统,它由带有液门原位化学处理的实时全息干涉装置和具有连拍功能的相机以及一台氦氮激光器组成,是一种简易实用的“低速、实时全息干涉摄影系统”。用它记录了火箭推进剂样品在室温,常压下的燃烧过程,100瓦普通只灯逐级加压的点燃过程,对实时全息图的记录和处理采用了一种可获得高反衬度的新技术,拍摄的成功率高,干涉条纹的反衬度好,它为研究物体的低速变化过程提供了一种有力的手 相似文献
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M. Miller 《Optics Communications》1979,28(2):156-158
It has been proven graphically and experimentally that the localization of interference fringes in classical interferometry is a specific case of the localization in holographic interferometry. 相似文献
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A. M. Lyalikov 《Technical Physics》2007,52(8):1040-1045
Superposed compensating holograms are shown to be a promising tool for solving a number of problems in real-time holographic interferometry, in particular, obtaining of interference patterns with fixed parameters of reference fringes and adjustment of the measurement sensitivity. The proposed approach is tested through visualization of the melting of a PMMA planar sample by means of lateral shear holographic interferometry. 相似文献
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We present a recent development in holography with multimode, large free-spectral range (FSR) diode lasers in photorefractive sillenite crystals. A novel refractometry method based on this type of holographic recording in Bi12TiO20 (BTO) crystals is proposed. The holographic image of a prism-shaped transparent sample appears covered of interference fringes, and as the sample is properly translated, the fringes run along the holographic image. An expression providing the refractive index of the medium as a function of the sample displacement and the correspondent number of running fringes was derived. The refractive indexes of optical (BK7) glass, ethanol, hexan, cumene and aqueous solution of NaCl with different concentrations were measured in order to test the method. The obtained results are in good agreement with the ones reported in literature or measured by us using a commercial Abbe refractometre. 相似文献
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A method for measuring contact pressures based on the measurement of irreversible changes in a surface microrelief by the speckle photography technique is presented. The analytic dependence between the change in the contrast of the carrying Young’s fringes and the relative area of change in the microrelief is considered. An example of a contact interaction between a cylinder end and a flat slab, the latter with a specially produced regular roughness on its contact surface, is used to experimentally verify the relation between the irreversible change in the roughness, the change in the contrast of the holographic interference fringes, and the change in the contrast of the carrying Young’s fringes. It is shown that the sensitivity of correlation speckle photography is higher than the sensitivity of the correlation holographic interferometry technique. 相似文献