Double-exposed Gabor holograms: a new approach to storage of information

The interface patterns obtained using doubly-exposed Gabor holograms of rough objects undergoing small axial displacement are investigated by treating the resulting speckle patterns as a system such as an array of slits. The reconstructed images, which are related to each other as separate identical diffusers that are correlated, give rise to an interference phenomenon in their Fourier plane. The resultant intensity is modulated by a ring system, the geometrical characteristics of which are dependent on the geometry of the arrangement. New formulae are obtained and their validity is substantiated by experiments.     

Waveguide holograms in optical computations

Conclusion The circuitry for optical computers is at present far from advanced, a reflection of the lack of well developed elements. Our investigations were aimed at demonstrating the capabilities of waveguide holography as a universal basis for the development of computer-structure elements, but the applications considered here do not exhaust all the possibilities of waveguide holography, since they touch upon (mainly) only one of the types of waveguide holograms.Translated from Preprint No. 46 of the Lebedev Physics Institute, Academy of Sciences of the USSR, Moscow, 1989.     

A new method for producing point holograms

A new method is proposed for producing point holograms by utilising highly correlated, extended sources rather than point-like sources in the recording process. The theory of this method is presented. Its feasibility is demonstrated experimentally. A multiple imaging experiment is described which utilises this kind of hologram. Advantages and limitations of holograms of extended sources are discussed.List of Symbols R complex amplitude of the reference wavefront in the hologram plane - S complex amplitude of the signal wavefront in the hologram plane - D complex amplitude of the reconstructing wavefront in the hologram plane - T complex amplitude of the reconstructed wavefront in the hologram plane - r complex amplitude of the wavefront illuminating the reference transparency - s complex amplitude of the wavefront illuminating the reference transparency - d complex amplitude of the wavefront illuminating the reference transparency - t complex amplitude of the wavefront illuminating the reference transparency - p amplitude transmittance of the reference transparency - amplitude transmittance of the signal transparency - (-function) amplitude transmittance of the reconstructing transparency - amplitude transmittance of the reconstructed transparency - P _r ,P _s propagation functions at distancesz _r ,z _s , respectively (equation 3) - x, y co-ordinates in the source plane - , co-ordinates in the hologram plane - z _r ,z _s distances of the reference, signal source from the hologram plane - X _r ,y _r co-ordinates of the reconstructing source (-function) - a, h shift co-ordinates in the autocorrelation integral (equation 12) - f _r,f _s Fourier transform operator at distances z_r,z _s (equation 7a) wavelength - k=2/ wavenumber - * conjugate complex - (*) convolution     

拍摄二步彩虹全息的新方法

本文提出与Benton法不同的拍摄二步彩虹全息的新方法.利用二次正全息像获得了二步彩虹全息的正重现像.分析表明,重现像的模、轴向放大率是匹配的,而且本方法排除了Benton二步法中使用会聚参考光的主要缺点.文中同时给出实验结果.     

一种制作多色彩全息图的新方法

本文首先提出了一种制作二维透射物彩虹全息图的新方法，即利用一专门设计的全息光学元件──色编码板，采用单光束制作所需物体的彩虹全息图；在此基础上，通过对色编码板的进一步理论设计，制作了一组对应不同主波长的色编码板，实现了记录物体的多色彩虹再现全息图。实验结果表明，此方案简便易行，光路布置灵活性高，且能有效地消除纵向色差的影响，特别适合于模压全息图制造中母全息图的拍摄，并降低了对环境稳定性的要求。     

A new theta modulation multiplexing scheme for computer-generated holograms

In this paper, a new theta modulation multiplexing scheme for producing multiplexed computer-generated holograms (CGHs) is proposed. Under this scheme, normal Lohmann-type CGHs are individually modulated by gratings with different orientations and then superimposed to form a single hologram. The proposed method results in a higher storage capacity without the increase of hologram space. Theoretical analysis and experimental results are presented.     

Concealed moiré pattern encoded security holograms readable by a key hologram

This paper describes a novel method of incorporating concealed coding features in security holograms in the form of moiré patterns, which need an encoded key hologram to decode them. These concealed codes in the holograms are in turn recorded with an encoded feature, so that these remain invisible to the counterfeiters thereby enhancing the anti-counterfeiting ability of security holograms. These security features, which are specific kinds of moiré patterns, can only be decoded by using an encoded key hologram in the final reading process. Though these type of security holograms are quite suitable for visual inspection, they possess high degree of anti-counterfeit ability and also do not require expensive reading machines. They can also be used as security codes for better protection against counterfeiting embossed holograms. Two different recording schemes for the formation of such security holograms and typical experimental results have been presented.     

二维彩色彩虹像面全息图记录的一种新方法

本文提出了利用液晶光阀和单色激光进行彩色全息图记录的方法.借助于液晶光阀非相干-相干转换的功能,采用新的彩虹全息术,获得了记录于同一块干版上的原彩色目标由红、绿、篮三色所成的三个基色彩虹全息像.用白光透射再现,得到原彩色图的真彩色全息像.这种方法是液晶光阀、条形散斑屏在图像处理中的一种特殊应用.     

A new approach to particle confinement

A new approach to permanent confinement of non-relativistic and relativistic particles inside microscopic regions of space is presented. Motion in suitably chosen energy-dependent potentials turns out to be such that the size of orbits of particles bound in such potentials decreases when energy is supplied to them from external sources and there exists a maximum size of these orbits. The energy spectrum is purely discrete without any continuum. The dynamics of such particles requires the introduction of a space-dependent metric in the Hilbert space of states to ensure conservation of probability.     

A new approach to peratization technique

The usual method of peratization technique is to expand scattering lengthA(a) in Born series in powers of the coupling constantg. In this paper a new approach to the peratization technique has been discussed starting with the standard equation for the scattering length. As an application of the theory developed, the cases of inverse fourth power and a logarithmic singular potentials have been discussed.     

A new approach to potential scattering

An approximate integral-representation of theS-matrix in partial-wave expansion is derived for a scalar Schrödinger particle in a central field. The method consists of linearizingCalogero's Riccati equation for the interpolatingS-matrix in such a way that the solution of the linearized equation deviates as little as possible from the exact one. TheS-matrix thus obtained exhibits exact crossing-symmetry and uniform convergence independent of the coupling constant of the scattering potential. In the weak coupling limit it is especially shown thatour method is more accurate than the second Born approximation. In the second part of the paper we specialize ourS-matrix to low and large energies. At low energies, a general integral for the scattering length is obtained and at large energies the summation over all angular momenta is carried out yielding an expression for the scattering amplitude.     

A new approach to Burger's equation

A new approach to Burger's equation is proposed using the decomposition method, eliminating smallness assumptions or linearization.     

A new approach to classical mechanics

A new approach to classical mechanics proposed by Prigogine, George, and Rae, which avoids the nonlinear Hamilton-Jacobi technique and introduces a linear eigenvalue problem involving probabilities as eigenvectors, is illustrated by the study of an exactly soluble model.     

A new approach to nonrenormalizable models

Nonrenormalizable quantum field theories require counter-terms; and based on the hard-core interpretation of such interactions, it is initially argued, contrary to the standard view, that counter-terms suggested by renormalized perturbation theory are in fact inappropriate for this purpose. Guided by the potential underlying causes of triviality of such models, as obtained by alternative analyses, we focus attention on the ground-state distribution function, and suggest a formulation of such distributions that exhibits nontriviality from the start. Primary discussion is focused on self-interacting scalar fields. Conditions for bounds on general correlation functions are derived, and there is some discussion of the issues involved with the continuum limit.     

A new approach to potential scattering

Potential scattering calculations based onCalogero's equation and given in two former papers are now improved to include unitarity of theS-matrix. It is shown that the method gives results better than the second Born approximation and even reasonable in the two limits of very strong coupling and very low energies. As test examples, the square-well potential and the Yukawa potential are discussed.     

Mode theory of three-dimensional superposed holograms: II. The wave field arising from the reconstruction of a superposed hologram

The wave field arising in the volume of superposed holograms is obtained with allowance for multiple wave diffraction on holographic cross-modulation gratings. It is shown that cross-talk interference waves are generated as a result of multiple diffraction, and their intensity depends on the degree of mutual orthogonality of hologram object waves.     

一种可用于原子全息光刻的二元计算全息新方法

 原子全息光刻即采用二元计算全息片掩模来操纵原子,实现微细结构的制作。传统二元计算全息产生的全息片在重现时会产生不止一个实像,这对于原子全息光刻的操作是不利的。提出了一种非相位编码的方法,该方法利用基元函数叠加方式产生实的编码前全息图,再利用类似罗曼Ⅲ型的编码方式产生二元计算全息图。模拟结果表明,利用该方法产生的掩模板可以产生单一的同原始图案相对应的微细结构。     

一种可用于原子全息光刻的二元计算全息新方法

原子全息光刻即采用二元计算全息片掩模来操纵原子,实现微细结构的制作。传统二元计算全息产生的全息片在重现时会产生不止一个实像,这对于原子全息光刻的操作是不利的。提出了一种非相位编码的方法,该方法利用基元函数叠加方式产生实的编码前全息图,再利用类似罗曼Ⅲ型的编码方式产生二元计算全息图。模拟结果表明,利用该方法产生的掩模板可以产生单一的同原始图案相对应的微细结构。