Showing papers in "Journal of Modern Optics in 1971"
TL;DR: In this paper, a double refracting interference microscope, which is capable of giving uniform and fringe interference field with both the amount and direction of image duplication continuously variable, has been developed.
Abstract: A double refracting interference microscope, which is capable of giving uniform and fringe interference field with both the amount and direction of image duplication continuously variable, has been developed. A combination of two simultaneously acting birefringent prisms, separated by a half-wave plate and inserted between a polarizer and analyser, is used. One of these prisms, of the Nomarski type, is incorporated in objectives and is rotatable round the objective axis. Rotation of this prism enables the amount and direction of image duplication to be changed. The other prism, of the Nomarski or Wollaston type, is placed in the microscope tube and can be slid in a direction perpendicular to the microscope axis. This translation serves for shifting the phase of interfering light waves, for measuring the optical path difference between an object under investigation and its surrounding medium. As a source of coherent light a slit diaphragm located in the front focal plane of a condenser is used. Both the sl...
132 citations
TL;DR: In this paper, the Fourier transform of in-plane moving objects is used to measure the lateral displacement of the moving object and its time averaged and doubly exposed speckle patterns.
Abstract: Time averaged as well as doubly exposed speckle patterns of in-plane moving objects are studied. These speckle patterns are recorded photo-graphically; their Fourier transform shows, interference fringes corresponding to the lateral displacement of the object. It leads to a very simple engineering tool for the analysis of mechanical vibrations as well as lateral displacements. Theoretical and experimental results will be shown.
101 citations
TL;DR: In the case of a periodic object, the wave amplitude in every point of a Fresnel diffraction pattern can be obtained from the values of the wave wave amplitude at a finite number of points in the object.
Abstract: In the case of a periodic object, the wave amplitude in every point of a Fresnel diffraction pattern may be obtained from the values of the wave amplitude at a finite number of points in the object...
99 citations
60 citations
TL;DR: In this paper, simple statistical detection theory is applied to the problem of detecting small images immersed in a background of laser-produced speckle, and the detection device is assumed to be a flying-spot type of scanning machine which has continuous scanning in both the x and y directions.
Abstract: Simple statistical detection theory is applied to the problem of detecting small images immersed in a background of laser-produced speckle. The detection device is assumed to be a flying-spot type of scanning machine which has continuous scanning in both the x and y directions. Two main points have emerged. Firstly, the size and transmittance distribution of an aperture used to scan the image are best determined by consideration of probabilistic quantities, and not by signal-to-noise ratio criteria. Secondly, in a typical detection problem of opaque discs in a speckle background, the geometrical image diameter should be at least four times the Rayleigh resolution limit of the lens used to form the image, for reliable detection.
46 citations
TL;DR: In this paper, the statistical properties of laser irradiance fluctuations beyond a layer of turbulent atmosphere were investigated, based on the phase screen approximation, and the treatment was based on phase-screen approximation.
Abstract: Statistical properties of laser irradiance fluctuations beyond a layer of turbulent atmosphere are investigated. The treatment is based on the phase-screen approximation.
41 citations
TL;DR: In previous OTF computer programs, various geometrical optical aspects of image formation appear often to have been ignored, leading to considerable errors in the computed values of the transfer function, particularly for high-aperture or wide-angle systems.
Abstract: In previous OTF computer programs, various geometrical optical aspects of image formation appear often to have been ignored. The neglect of factors associated with anamorphotic imagery, pupil aberrations and vignetting, and a shift of focal plane can lead to considerable errors in the computed values of the transfer function, particularly for high-aperture or wide-angle systems. In addition, the numerical integration processes employed have not always been entirely satisfactory in terms of efficiency, generality, and convenience.
36 citations
32 citations
TL;DR: In this paper, the spectral and correlation characterizations of intensity fluctuations of irradiance of an incident coherent light wave propagating through a turbulent medium are studied. But the spectral properties of the light wave are not investigated.
Abstract: The spectral and correlation characterizations of intensity fluctuations of irradiance of an incident coherent light wave, propagating through a turbulent medium, are studied.
31 citations
TL;DR: In this article, the Polarized Light and Optical Measurement (PLOMIM) method is used to measure the optical properties of light and optical measurements in the presence of polarized light.
Abstract: (1971). Polarized Light and Optical Measurement. Optica Acta: International Journal of Optics: Vol. 18, No. 10, pp. 794-794.
31 citations
TL;DR: In this paper, the authors derived expressions for transmittance and reflectance of light for a multilayer system containing one thick layer using amplitude transfer matrices and intensity transfer-matrices.
Abstract: Expressions for transmittance and reflectance of light for a multilayer system containing one thick layer are derived by the method of amplitude transfer-matrices. For polychromatic light, conditions are given, such that those of the interference fringes which are due to the thick layer will be negligibly weak; an error estimate is given. An alternative method, that of intensity transfer-matrices, allows one to derive expressions in which the fringes due to an arbitrary number of thick layers are eliminated, while the interference effects caused by the thin layers are retained.
TL;DR: In this article, the influence of random wavefront errors on the transfer function and point spread function of an optical system is studied theoretically, where the stochastic transformation from wavefront to transfer function is non-linear.
Abstract: The influence of random wavefront errors on the transfer function and point spread function of an optical system is studied theoretically. The stochastic part of the aberration function is assumed to be Gaussian and spatially stationary (although the requirement of stationarity is relaxed in § 5). The stochastic transformation from wavefront to transfer function is non-linear. The consequences of this non-linear transformation are two-fold: first, the statistics of the transfer function are non-Gaussian, second, the transfer function is non-stationary. (The same statements hold for the point spread function.) Therefore the characterization of these processes requires an infinite number of averaged products (moments), not just the first two if the processes were Gaussian. These averaged products are obtained in the form of multiple integrals involving the characteristic function of the wavefront and are suitable for calculation on a high speed computer. Some numerical results for the mean of both processes...
TL;DR: In this article, an equation for weakly absorbing powdered samples was derived by representing a powdered sample as a collection of rough-surfaced spherical particles of uniform diameter, which relates the diffuse reflectance to the index of refraction, absorption coefficient and particle diameter.
Abstract: By representing a powdered sample as a collection of rough-surfaced spherical particles of uniform diameter, an equation was derived which relates the diffuse reflectance to the index of refraction, absorption coefficient and particle diameter. The equation, which is extremely simple in form for convenient application, is applicable for weakly absorbing powdered samples. It was tested by the use of published experimental data.
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TL;DR: In-water photography: In-water Photography as mentioned in this paper is a popular technique for in-water photo-taking, and it has been used extensively in the field of computer vision.
Abstract: (1971). In-water Photography. Optica Acta: International Journal of Optics: Vol. 18, No. 4, pp. 321-321.
TL;DR: In this article, a review of the present knowledge of conventional polishing techniques is presented, concentrating particularly on the pitch polishing technique for high precision optical surfaces, which still depends completely on the artistry of highly skilled opticians who have a largely intuitive understanding of the process.
Abstract: A review of the present knowledge of conventional polishing techniques is presented, concentrating particularly on the pitch polishing technique for high precision optical surfaces. This technique still depends completely on the artistry of highly skilled opticians who have a largely intuitive understanding of the process. The aim of this article is to point out that the course of surface shape development during the polishing process can be explained in terms of available technical knowledge and consequently that an improvement of polishing technique, based on this knowledge, is feasible.
TL;DR: In this article, different methods of measuring the modulation transfer function of photographic emulsions are discussed in four sections; sine wave methods, Fourier transformation of the line spread function, coherent light processing methods, and calculation from scattering measurements.
Abstract: The different methods of measuring the modulation transfer function of photographic emulsions are discussed in four sections; (i) sine wave methods, (ii) Fourier transformation of the line spread function, (iii) coherent light processing methods, and (iv) calculation from scattering measurements. Particular attention is paid to the effects of the non-linearities of the photographic process, and to the effects of film grain noise on the measured transfer function. A brief discussion of the related microdensitometry is also included.
TL;DR: In this article, the methode de spectrographie interferentielle decrite en [1, 2] corresponde correspondre to a methode of spectrographe et al. [3].
Abstract: Nous exposons la methode de spectrometrie interferentielle decrite en [1, 2], a laquelle nous avons fait correspondre une methode de spectrographie interferentielle [3]. Nous montrons que ce procede de spectrometrie, qui permet, a resolution donnee, un gain d'etendue geometrique des faisceaux SΩ eleve (donc un gain de luminosite en spectrometrie, les photorecepteurs etant sensibles au flux) et donne lieu a differentes realisations, met toujours en jeu un phenomene fondamental qui est l'analyse ou le filtrage par ‘resonance spatiale’ du phenomene a l'infini de tout systeme interferentiel isotrope ou anisotrope [1]. Nous exprimons par ‘resonance spatiale’ le phenomene resultant de la coincidence des franges repondant a une certaine loi (franges d'Young a l'infini ou a distance finie, franges a l'infini en general (interferometre de Michelson, Fabry-Perot, etc.) franges du coin), dont le pas depend de la longueur d'onde, avec une structure achromatique (reseau par transmission ou reflexion, photographie d'an...
TL;DR: In this article, the authors show that the Bildfehler einer Rontgenstrahlenoptik, die nahe der Kantenzone benutzt wird, sind durch Δ≈f (α2δ + αδ2-¼δ3) abgeschatzt.
Abstract: Die Bildfehler einer Rontgenstrahlenoptik, die nahe der Kantenzone benutzt wird, sind durch Δ≈f (α2δ + αδ2-¼δ3) abgeschatzt. f ist die Brennweite, δ der Winkel zwischen Einfallsrichtung und Achse, α der Winkel zwischen Strahl und Achse im Achsenpunkt des Bildes. Der erste Summand gibt die Koma, der zweite entspricht dem Astigmatismus, der letzte der tonnenformigen Verzeichnung. Da der Offnungsfehler in der Achse verschwindet, gibt das Ergebnis eine vollstandige ‘Seidelsche’ Entwicklung. Die strengen Formeln fur die Aberrationen werden angegeben.
TL;DR: The concept of image quality by means of the optical transfer function (OTF) is traced from the early use of sine wave test charts through to the development of the high precision OTF.
Abstract: The concept of the assessment of image quality by means of the optical transfer function (OTF) is traced from the early use of sine wave test charts through to the development of the high precision...
TL;DR: In this paper, the authors derived a theoretical expression for the intensity distribution in the diffrimoscopic image for a straight edge under partially coherent illumination and showed that the fringe width is practically independent of the degree of coherence and of the obstacle width but is inversely proportional to the width of the aperture.
Abstract: A theoretical expression has been derived for the intensity distribution in the diffrimoscopic image for a straight edge under partially coherent illumination. Computations have been made to see (a) the effect of the degree of coherence, (b) the effect of the width of the aperture, and (c) the effect of obstacle width. It has been shown that the dark fringe appears exactly in the position of the geometric image of the edge and that the fringe width is practically independent of the degree of coherence and of the obstacle width but is inversely proportional to the width of the aperture.
TL;DR: In this article, the association of deux reseaux par transmission, places parallelement l'un a l'autre et eclaires en lumiere spatial incoherente, permet d'obtenir dans differents plans de mise au point, paralleles aux reseaux, des franges observables in lumiere blanche.
Abstract: L'association de deux reseaux par transmission, places parallelement l'un a l'autre et eclaires en lumiere spatialement incoherente, permet d'obtenir dans differents plans de mise au point, paralleles aux reseaux, des franges observables en lumiere blanche. On montre que dans certaines conditions, on peut realiser des franges dont la loi de repartition des intensites est independante de la longueur d'onde.
TL;DR: In this paper, the resolution requirements of the camera and reproducer were considered for television holography systems with particular emphasis on the resolution requirement of the reproducer and the camera.
Abstract: Television holography systems are considered with particular emphasis on the resolution requirements of the camera and reproducer. Methods are shown whereby conventional cameras and reproducers can...
TL;DR: Paraxial ray tracing offers a rapid method of determining which surfaces, if any, are likely to cause significant veiling glare and is intended to be used at the design stage.
Abstract: Veiling glare can cause significant deterioration of image quality in many systems. One of the sources of veiling glare, that of multiple reflections, can be investigated in the paraxial approximation. Paraxial ray tracing offers a rapid method of determining which surfaces, if any, are likely to cause significant veiling glare. The procedure outlined here is intended to be used at the design stage.
TL;DR: A theory of foveal vision is developed and the product of this theory is an equation enabling the prediction of threshold detection values for specific target stimuli.
Abstract: Starting from a knowledge of the physical structure of the human eye, and making certain assumptions about the nature of neural processing, a theory of foveal vision is developed. The product of this theory is an equation enabling the prediction of threshold detection values for specific target stimuli. Good agreement is achieved with the practical results drawn from a number of threshold experiments of different types.
TL;DR: In this paper, a simplified test procedure was developed that uses only the 45° target orientation, where the lenses under test are focused for a given frequency on-axis and off-axis.
Abstract: A simplified test procedure was developed that uses only the 45° target orientation. The lenses under test are focused for a given frequency on-axis. The on-axis MTF curve is recorded in one azimuth position of the lens, and the off-axis MTF curves for one selected field angle are recorded in three azimuth positions, The results obtained on ten lenses, each of two different lens types, will be presented in comparison with the results of photographic resolution tests on the same lenses. The results obtained from MTF testing appear to give better differentiation of lenses at a lower cost.
TL;DR: In this article, a combination of two dielectric layers, each with an optical thickness of less than a quarter wave, behaves to a great extent as one quarter wave layer, and it is shown that a combination can be viewed as a two-layer network.
Abstract: It is shown that a combination of two dielectric layers, each with an optical thickness of less than a quarter-wave, behaves to a great extent as one quarter-wave layer
TL;DR: In this article, the Schmidt correction of the camera in a spectrograph was studied in which it was effected in the collimator, and the limit of camera aperture for which these aberrations are tolerable is between F/D=4 and F /D=3 according to the size and number of lines of the grating.
Abstract: Of the different ways to introduce the Schmidt correction of the camera in a spectrograph, the case was studied in which it is effected in the collimator. Equations which describe the form of the wave-front at one side of the grating as function of the form at the other side were found. The sixth-order terms in the correction to compensate for the deformation of the wave-front in the path from the collimator to the grating and to the mirror were also found. The aberrations for a correction which is symmetrical around the collimator axis were calculated. The limit of camera aperture for which these aberrations are tolerable is between F/D=4 and F/D=3 according to the size and number of lines of the grating.