Showing papers in "Journal of Modern Optics in 1972"
TL;DR: In this paper, surface displacement can be measured by recording a double-exposure photograph of the laser-illuminated object, followed by optical processing of the recorded speckle-pattern image.
Abstract: Surface displacement can be measured by recording a double-exposure photograph of the laser-illuminated object, followed by optical processing of the recorded speckle-pattern image. The analysis can either be on a point-by-point basis, or by a spatial filtering technique which resolves the motion in any desired direction orthogonal to the line of sight. The limits within which the technique may be used to measure lateral translations and rotations of the surface are examined theoretically and experimentally, and the effect of lens aberrations and surface scattering properties are discussed. Surface tilt may also be measured by recording a defocused double exposure image and analysing its optical transform. The photographic techniques described can be extended to measuring surface vibration, by recording a single ‘time-averaged’ exposure and examining the modified optical transform fringe pattern.
294 citations
TL;DR: In this article, the effects of errors in the turning value method of film-thickness monitoring on the performance of all-dielectric interference filters were studied theoretically by both an accurate and an approximate method, and it was shown that although the potential accuracy of the method in monitoring a single layer is very poor, the theoretical accuracy of peak frequency and the overall performance of complete narrow-band filters are extremely good.
Abstract: The effects, on the performance of all-dielectric interference filters, of errors in the turning value method of film-thickness monitoring, are studied theoretically by both an accurate and an approximate method. It is shown that, although the potential accuracy of the method in monitoring a single layer is very poor, the theoretical accuracy of peak frequency and the overall performance of complete narrow-band filters are extremely good. Poor performance of real production filters is therefore unlikely to be due to an inherent limitation of the method, but rather to a faulty application of it, or to other factors unconnected with the monitoring method.
131 citations
TL;DR: In this paper, the Kirchhoff theory of diffraction was extended to the case of a simple randomly rough surface, and the influence of surface roughness on the ellipsometric parameters was investigated.
Abstract: The theory of the influence of surface roughness on the ellipsometric parameters j and of simple randomly rough surface is developed in the framework of the Kirchhoff theory of diffraction. This theory is also extended to the following systems: rough surface—isotropic homogeneous identical film (both ambient-film and film substrate boundaries are geometrically identical; and rough surface—isotropic homogeneous general film (both boundaries are geometrically, and therefore also statistically, independent). Also the numerical analysis of the theoretical results is performed and the most important aspects of dependencies of j and on surface roughness (characterized by slopes of the height irregularities) and of the angle of incidence are found which enable us to determine the values of these slopes. The correctness of the theory is demonstrated on a system formed by the rough surface of a silicon single crystal covered with natural surface film, with the character of an identical film. It is shown that w...
96 citations
TL;DR: The results and calculations are presented, the validity of this approach is discussed, and the axial spherical aberrations of an emmetropic eye are measured and used as the average curve of axial spheres of a living eye.
Abstract: Several optical models of the eye have been proposed [1–6]. However, in all of them the distribution of refractive indices was taken either from biological or embryological data or from measurements on frozen sections of the lens. The optical performance of these models was a result of this design, and not its basis. Therefore, these models are not suitable for a study of the internal structure of the crystalline lens.
58 citations
TL;DR: In this article, the central part of the condenser of a microscope may be obstructed by obstructions, and it is shown that in certain circumstances there may be more than one separation at which two points are just resolved.
Abstract: By obstructing the central part of the condenser, the resolution of a microscope may be improved. In the results presented, it is shown that in certain circumstances there may be more than one separation at which two points are just resolved.
48 citations
TL;DR: In this paper, the authors compared the Kubelka-Munk equations describing the diffuse reflectance of a powdered sample to equations obtained using a uniformly-sized rough-surfaced spherical particle model.
Abstract: The Kubelka-Munk equations describing the diffuse reflectance of a powdered sample were compared to equations obtained using a uniformly-sized rough-surfaced spherical particle model. The comparison resulted in equations relating the remission function and the Kubelka-Munk constants to the index of refraction, the absorption coefficient, and the average particle diameter of a powdered sample. Published experimental results were used to test the equation relating to the remission function to the fundamental optical parameters.
46 citations
TL;DR: In this paper, a method for measuring the spatial coherence of light by means of speckle patterns produced by using ground glass as a random inhomogeneous medium is described, and its verification is performed experimentally by using a laser and a mercury lamp as light sources.
Abstract: A method is described for measuring the spatial coherence of light by means of speckle patterns produced by using ground glass as a random inhomogeneous medium. The theory of the method is developed and its verification is performed experimentally by using a laser and a mercury lamp as light sources. Characteristics of the present method for exploring the spatial coherence of light fields are discussed.
42 citations
36 citations
TL;DR: In this paper, a general theory of diffraction by gratings is applied to gratings with a sinusoidal profile, and also to grating with a homogeneous profile.
Abstract: A general theory of the diffraction by gratings is applied to gratings with a sinusoidal profile (of interest since the advent of holographic techniques in grating production), and also to gratings...
35 citations
TL;DR: In this paper, the relation of optical and lyrinthean orientations is discussed, and the relation between optical and labyrinhean orientation is discussed. But this paper is limited to a single image.
Abstract: (1972). Relation of Optical and Labyrinthean Orientation. Optica Acta: International Journal of Optics: Vol. 19, No. 5, pp. 467-471.
32 citations
TL;DR: In this article, the second degree aperture terms in the wavefront aberration function are obtained for a general holographic system, no approximation being made for the inclinations of the reference waves in either the recording or the reconstruction.
Abstract: A formula, which is the equivalent of the law of refraction for a single refracting surface, is derived for the holographic case. The second degree aperture terms in the wavefront aberration function are obtained for a general holographic system, no approximation being made for the inclinations of the reference waves in either the recording or the reconstruction. These second degree terms are used to define the location of the image point. It is shown that, where the reconstruction reference wave differs appreciably from that used for the recording of the hologram, the image is not merely magnified or reduced, but is also anamorphotic. Formulae are derived for the azimuths of each of the principal sections and for the two magnifications in these sections. It is then possible to establish the nature of holographic image formation in the general case.
TL;DR: A total aberration formula is defined as one which gives total ray or optical path aberration from finite ray trace data as discussed by the authors, which is the maximum possible conservation of numerical precision.
Abstract: A total aberration formula is defined as one which gives total ray or optical path aberration from finite raytrace data. Some known expressions of this kind are reviewed and a new expression for optical path aberration along skew rays is developed; this expression gives the maximum possible conservation of numerical precision.
TL;DR: In this paper, the authors present a historical review of the history of speckle patterns in Optica Acta: International Journal of Optics: Vol. 19, No. 9, pp. 791-793.
Abstract: (1972). Speckle Patterns: A Historical Retrospect. Optica Acta: International Journal of Optics: Vol. 19, No. 9, pp. 791-793.
TL;DR: In this paper, the Fraunhofer diffraction patterns from apertures of the form of an equilateral triangle, a square, a regular pentagon, a hexagon and an octagon are compared with the calculated maps of the intensity distribution.
Abstract: In this second contribution the Fraunhofer diffraction patterns from apertures of the form of an equilateral triangle, a square, a regular pentagon, a hexagon and an octagon are compared with the calculated maps of the intensity distribution. For each shape of the aperture the first few maxima and minima of the intensity are tabulated and the formulae for the wave function are given characterizing the diffraction in the directions of the slowest and the steepest decrease of intensity.
TL;DR: In this article, the authors made a theoretical study of self-focusing of an electromagnetic wave in a medium with saturating nonlinearity and obtained explicit conditions for focusing and defocusing.
Abstract: We have made a theoretical study of self-focusing of an electromagnetic wave in a medium with saturating non-linearity. Explicit conditions for focusing and defocusing have been obtained. All results have been obtained by taking into account the effects of diffraction.
TL;DR: In this paper, a formulation for investigating the intensity distribution of Fresnel diffraction by a circular aperture illuminated with partially coherent light was developed for the normal axis to the aperture in the diffraction field when the spatially mutual coherence function of the illumination over the aperture takes three different forms.
Abstract: A formulation is developed for investigating the intensity distribution of Fresnel diffraction by a circular aperture illuminated with partially coherent light. The theory formulated is applied to obtain the intensity distribution along the normal axis to the aperture in the Fresnel diffraction field when the spatially mutual coherence function of the illumination over the aperture takes three different forms. It is shown that the Fresnel diffraction is largely influenced by the coherence condition across the diffracting aperture.
TL;DR: In this paper, it has been shown that the Sparrow limit is independent of the original object contrast and depends on the degree of coherence between the object particles, where o is the coherence of the pair of points.
Abstract: The classical approach to the study of two-point resolution has considered the case of two infinitesimal pinholes in an opaque screen. Since partially coherent imagery is non-linear with respect to either intensity or amplitude, the question of resolution needs to be re-examined for a pair or point-like particles embedded in a medium of finite but different transmission. This paper deals with this situation in ordinary microscopy. It has been found that the limit of resolution may be expressed as 0 + j , where 0 is the limit obtainable on the basis of the Sparrow criterion, and is seen to be independent of the original object contrast. The second term j is an incremental term that depends on the object contrast and the final required image contrast. Both terms, however, depend on the degree of coherence between the object particles. A simple semi-empirical expression K s = 0 sin f / u = 0·475 + 0·26 o gives the Sparrow limit of resolution, where o is the coherence between the pair of points. Curv...
TL;DR: In this paper, the spectral and correlation properties of intensity fluctuations of irradiance of a focused transmitter, beyond a layer of rubulent atmosphere, were studied and the range of large values of the phase structure function, computed on the transmitter aperture size, where saturation of fluctuations was predicted.
Abstract: The spectral and correlation properties of intensity fluctuations of irradiance of a focused transmitter, beyond a layer of rubulent atmosphere, are studied. Of particular concern is the range of large values of the phase structure function, computed on the transmitter aperture size, where saturation of fluctuations is predicted. The analysis is based on the phase-screen approximation.
TL;DR: The spectral sensitivity of rhesus monkeys has been accounted for as the upper envelope of three response channels, the sensitivities of two of which are determined by inhibitory interaction as mentioned in this paper.
Abstract: The spectral sensitivity of rhesus monkeys has been accounted for as the upper envelope of three response channels, the sensitivities of two of which are determined by inhibitory interaction betwee...
TL;DR: In this paper, a plaque photographique haute resolution is described, where a faisceau parallele de lumiere monochromatique is placed at the derriere de diffuseur.
Abstract: Un diffuseur d'amplitude est eclaire par un faisceau parallele de lumiere monochromatique. Une plaque photographique haute resolution est placee derriere de diffuseur. On fait N poses entre lesquelles le diffuseur est deplace parallelement a l'axe optique du faisceau d'une quantite k. La plaque photographique est developpee et eclairee par un faisceau de lumiere parallele. On observe a l'infini un systeme d'anneaux a ondes multiples (N ondes).
TL;DR: In this article, a simple approximation of the wavelength of single frequency He-Ne laser as a function of temperature, pressure and relative humidity is presented, suitable for the simple application in the portable laser interferometer.
Abstract: A simple approximation of the wavelength of single frequency He-Ne laser as a function of temperature, pressure and relative humidity is presented. This approximation is suitable for the simple application in the portable laser interferometer. Comparison with the Owens and Edlen formulae is also presented and it is shown that the linear correction limits its accuracy.
TL;DR: The data indicated that the orientation of the individual stereoscopic reference curves approached the objective normal where the stimulus pattern contained distinct vertically separated contours.
Abstract: Variation in the orientation and shape of the stereoscopic frame of reference in the horizontal meridian was investigated in response to (a) asymmetric convergence of the eyes and (b) afocal overall and meridional magnifiers. The stimulus patterns were varied from those that offered few clues as to vertical limits to those that contained definite vertically separated contours above and below the fixation target. Readings were taken at three observation distances. The data indicated that the orientation of the individual stereoscopic reference curves approached the objective normal where the stimulus pattern contained distinct vertically separated contours. The results confirmed previous findings that the induced size effect could not alone account for these changes in orientation of the reference curves. Changes in shape of the curves also occurred. The average shape of these curves was characteristic for the individual and it varied with the examination distance in such a way, that, at least qualitativel...
TL;DR: In this article, exact and approximate formulae are obtained for counting statistics of mixed cosine-modulated coherent and partially polarized chaotic light, particularly with Lorentzian spectrum, for one-photon as well as multiphoton absorption.
Abstract: Exact and approximate formulae are obtained for the counting statistics of mixed cosine-modulated coherent and partially polarized chaotic light, particularly with Lorentzian spectrum, for one-photon as well as multiphoton absorption They are numerically analysed and the accuracy of the approximate formulae is discussed As a special case chaotic light is investigated A closer relation to recent papers is outlined
TL;DR: In this paper, a lateral shear interferogram of a phase object is obtained when a Ronchi ruling is photographed through the object, and an analysis of the technique is given from the point of view of diffraction theory and it is shown that a source of large spectral bandwidth can be employed.
Abstract: A lateral-shear interferogram of a phase object is obtained when a Ronchi ruling is photographed through the object. An analysis of the technique is given from the point of view of diffraction theory and it is shown that a source of large spectral bandwidth can be employed. The effect of source size is also discussed. The lateral shear can easily be varied by altering the distance of the object from the grating. The experimental set-up can be modified so as to obtain an absolute interferogram which is also an image hologram of the object. The source size and its spectral bandwidth are severely limited in the modified arrangement.
TL;DR: In this article, a methode de calcul permettant d'obtenir les constantes optiques de materiaux isotropes and uniaxes a partir de mesures de pouvoir reflecteur effectuees en lumiere partiellement polarisee lineairement.
Abstract: On decrit une methode de calcul permettant d'obtenir les constantes optiques de materiaux isotropes et uniaxes a partir de mesures de pouvoir reflecteur effectuees en lumiere partiellement polarisee lineairement. Cette methode est basee sur une minimisation de l'ecart quadratique moyen entre les valeurs calculees et experimentales.
TL;DR: In this article, the spectral transmittance of tandem arrays of multilayer filters is measured and compared with theory, assuming that the irradiances of the multiply reflected beams can be added incoherently.
Abstract: The spectral transmittance of tandem arrays of multilayer filters is measured and compared with theory. The theory assumes that the irradiances of the multiply reflected beams can be added incoherently. Various arrangements of tandem arrays are examined in order to optimize the attenuation in the long-wavelength spectral region of an ultra-violet bandpass filter.