物面单反射镜波前分割三光束全息干涉计量研究

提出了一种用于分析物体三维位移场的全息干涉计量新方法。该方法将一个小平面反射镜贴于被测物体的表面，用三束呈空间分布的发散光波，在干版的三个不同区域或同一部位，记录被测物体的三个独立的双曝光干涉图。这些干涉图被由小平面反射镜运动造成的参考光虚点光源的位移所调制。基于对这种调制的理论分析，导出计算参考光虚点光源和被测物体三维位移的二个线性方程组。     

用空间滤波方法制作θ调制全息物片

给出了一种制作θ调制全息物片的新方法.在空间滤波光学系统的频谱面上放置只允许±1级频谱通过的滤波器,当单色平行光垂直照射物平面上的一维光栅时,将在像平面上得到两个重叠的一维光栅像,同时在成像区域形成光强按余弦规律变化的干涉条纹.用装有镂空模板和全息干版的可旋转组合干版夹对干涉条纹进行3次等时曝光,记录下3种不同干涉条纹方向的图案,即可制作出θ调制全息物片.     

一种新型的散斑干涉实验

本文介绍了一个用CCD摄像机代替常规的全息干版记录图像．并存储在计算机里进行计算机处理．在电视屏幕上实时观察到干涉散斑场的相关条纹．从而测量出物体微小位移的光、电与计算机相结合的综合实验．     

利用迈克尔逊干涉仪制备全息光栅

利用迈克尔逊干涉仪上调节出的等厚干涉条纹,将全息干版放置在观察屏处曝光,经过处理后得到全息光栅,利用分光计测出光栅常数.     

一种新型的散斑干涉实验

本文介绍一个用ＣＣＤ摄像机代替常规的全息干版记录图像，并存储在计算机里进行计算机处理，在电视屏幕上实时观察到干涉散斑场的相关条纹，从而测量出物体微小位移。是一个光、电与计算机相结合的综合实验。     

用光栅编码实现干涉图和阴影图的超快分幅记录

一束激光被分成几束子光束,每子光束具有不同的延时并用以不同方位放置的光栅对它编码.用一系列反射镜将这些子光束汇合成一束,并用来对客体进行全息干涉和阴影诊断.解调之后,可从全息底片获得对应于各个不同时刻的一系列干涉图或阴影图.     

编码非相干光源光栅干涉仪

利用光栅进行相衬观察位相物体，光栅作为分束器获得双光束，将双光束干涉条纹调制在位相连续变化的物体上可以支位相物体的折射率进行定量测量。采用编码非相干光源抑制相干噪音，使输出图像更为清晰。     

多光束数字全息的研究

提出了一种多光束数字全息技术来解决当利用菲涅耳数字全息对全息图进行再现时,物体的多个表面无法同时再现得明亮、清晰.该方法是记录时采用多光束照明同一物体的多个表面,增强CCD上接收到的物体侧表面散射光的强度.实验成功地同时再现了物体的多个表面.同时,为了减弱再现像的散斑噪声,采用双线性插值和中值滤波处理图像,获得了质量高的三维物体的再现图像.     

平面全息透射光栅状态的调节

平面全息透射光栅是用全息干版记录下稳定的干涉条纹得到的。如果干版的片基两表面不平行,栅面就相当于附着在一块楔角很小(约几分)的棱镜上,这给光栅状态的调节带来一定的困难。根据我们的经验,只     

激光全息术中的光信息调制与解调分析

通过对激光干涉全息理论和调幅信号的调制与解调理论的类比分析,说明激光全息理论可以从信息的调制与解调的角度描述和理解,在此基础上,简要阐述了分波面干涉、分振幅干涉对空间等光程信息的调制和光通过狭缝后衍射图样对狭缝宽度信息的解调过程.     

二步合成平板周视彩虹全息术

提出一种将物光波前先分解记录，再合成的二步平板周视彩虹全息术。波前的分解记录与合成彩虹全息图是分别通过转动物体和干板来实现的。记录这种周视全息图，不需要大孔径和其它特殊光学元件，即可获得周视半径大的无象差立体再现象。该方法可直接用于模压全息图母板的制作。     

Fringe order determination and zero motion fringe identification in holographic displacement measurements

In addition to holograms of the underformed and deformed object, a third hologram is recorded during the deformation process, on the same holographic plate: this marks parts of the test object which have not moved. The zero order fringe, which corresponds to zero motion, is reconstructed from the triple-exposure hologram with much greater intensity than the fringes of higher order.     

Holography with local reference beam obtained by spatial frequency separation

The holographic method disclosed in this paper allows holographic recording with a very high reference-to-object wave energy ratio without attenuating the rays diffracted by the object. In those holographic methods permitting local generation of the reference beam, which have been proposed so far, the reference beams are obtained by either wavefront or amplitude division of the wave of coherent radiation impinging onto the optical apparatus. It is readily seen that most of the incident energy is used to process the reference beam reducing drastically the energy of the object bearing wave. In the novel method proposed here the reference wave is obtained by separation of the low spatial frequency components from the high-order spatial frequency components which bear the object information. As a result of the removal of the low frequency components, a dark-field image is recorded and later reconstructed by the holographic plate. Even though the configuration is of the off-axis type, proper design may reduce the coherence requirements of the source of radiation to those for in-line holography. The paper discusses the basic properties of the method and experimental results are presented. This work forms part of a dissertation to be submitted by M. L. A. Gassend in partial fulfillment of the requirements for the Ph.D. degree. It has been supported by the National Research Council of Canada under Grants Nos. A 7240 and T 0409, and by the Department of External Affairs (Award No. 759193 administered by the Canada Council).     

利用相位模板实现数字全息超分辨成像

为了简化数字全息超分辨记录系统,分别在其物光和参考光部分引入一块相位模板,以获得垂直和倾斜方向照明物体的光束和具有不同载波频率的参考光束.当这些具有不同照射方向的光透过物体后,可以使CCD在位置固定的情况下记录到携带低频和高频信息的物体衍射场,不同载波频率的参考光则保证了高频和低频信息在复合全息图的频谱面上能够相互分离.实验结果证明,通过将记录到的物体高频和低频信息合成,可以获得超出系统衍射极限分辨率的再现像.     

Resolution improvement of digital holographic images based on angular multiplexing with incoherent beams in orthogonal polarization states

We present a method to improve the resolution of digital holographic images based on angular multiplexing with incoherent beams from two orthogonal polarized components of natural light. Two incoherent subholograms are synchronously recorded by two pairs of incoherent object waves and reference waves with orthogonal polarization states, in which the object is illuminated by two incoherent beams from different directions. The increase in resolution is obtained through phase correction and superposition of two reconstructed object waves. Experimental results show that the resolution and quality of the reconstructed image can be effectively improved.     

Multiple-exposure high-sensitivity holographic interferometry for studying moving objects

A method for increasing the sensitivity of measurements through aberration compensation upon reconstruction of interferograms from two multiple-exposure holograms is proposed. At the early stage of object investigation, the holographic structures recorded at certain time instants are rerecorded by two coherent beams on new image carriers. In this case, the interference moiré method is employed to monitor the equality of the vectors of the holographic structures rerecorded. At the final stage, the new nonlinear holograms are processed in an optical analyzer of conjugate holograms with the use of incoherent light. The hologram thus reconstructed offers a high sensitivity of measurements and is free of aberrations. The method is tested by visualizing the temperature-field variations in a glass substrate with a conducting coating.     

Dynamic recording of χ<Superscript>(2)</Superscript> holograms with multifrequency object and reference waves

The transformation properties of images formed by inertialess dynamic χ⁽²⁾ holograms recorded by multifrequency reference and object beams are studied theoretically and experimentally. The regular features of the spatial localization and scales of holographic images obtained with different frequency combinations of the reference and object image-forming beams are ascertained. It is shown that, in the general case of an arbitrary variation in the ratio of these frequencies, the reconstructed images of an object point source are localized on a segment of a straight line, which we referred to as the locris. The slope of the locris does not depend on the frequency ratio of the reference and object beams, and its endpoints are specified by the positions of the reference and object sources. The possibility of obtaining of achromatic holographic images for noncollinear multifrequency interactions is demonstrated. The conditions for the noncollinear phase matching of interacting waves in a KTP crystal, as well as for simultaneous attainment of phase matching for selected frequency combinations, are determined. The important role of controlling the shape of wavefronts in experiments with frequency conversion of radiation in the reference beam by stimulated Raman scattering of light is ascertained.     

Holographic recording and retrieval of polarized light by use of polyester containing cyanoazobenzene units in the side chain

We examined the holographic recording properties of polyester containing cyanoazobenzene units in the side chain. It was revealed that, when a linearly polarized object beam with an arbitrary polarization direction was recorded, the retrieved beam had the same polarization state as that of the object beam, with a constant diffraction efficiency of 0.1. Moreover, two object beams with mutually orthogonal linear polarization could be recorded and retrieved separately from the same area. This is, to our knowledge, the first example of holographic polarization multiplexing. The retrieved images were found to resolve details of ~40line pairs/mm and a 40-mum -pitched checkerboard pattern. The resolution of the system is limited by the CCD cameras that are used. Polarization encoding to increase the storage capacity and (or) the signal-to-noise ratio of holographic data recording is also discussed.     

光纤全息散斑干涉计量

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。