These are the latest articles published in Nouvelle Revue d'Optique.

• Open/close Phase-profile realisation and quantification of phase information

  J J Clair 1973 Nouvelle Revue d'Optique 4 251 Tag this article

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  We have studied the influence of the quantification of phase information on the amplitude diffracted by a phase profile.

  At first with a one dimensional profile, then with a two dimensional one, we get a signal to noise ratio, which depends on the number of steps of quantification.

  To avoid the parasite images, we have imagined a new method, which with an optical trick, allows us to drawn all sort of intensity pattern and phase pattern, if we work directly on photoresist.

  The number of steps may be very large, and it is possible to synthesize all sort of profile, as kinoform, aspherical surfaces... The profile may be considered as continuous and the very little thickness of such filters give the possibility to use them in miniaturised optical devices.

  The presented apparatus is all automatised and permits an economy in time and money, in comparaison with the classical and well known methods using plotter and printing machines controled by computer.

  Such surfaces are used as test for aspherical ones and as correction plates; we present here the realisation of a parabolic lens.

• Open/close Holographic storage of multiple images using spatial division in Fourier plane

  C P Grover and M May 1973 Nouvelle Revue d'Optique 4 281 Tag this article

  Article References Full text PDF (799 KB)

  A new holographic method for multiple storage of images has been suggested in which the spectra of low frequency signals are made to spread widely in the Fourier transform plane, by modulating them with a high frequency random diffuser. The Fourier transform plane is divided into a number of non-overlapping areas and with each of them is associated a signal. Due to symmetry of revolution about the optical axis, the spatial division of the frequency plane is made by using annular filters of different diameters. The directly transmitted beam corresponding to zero spatial frequency provides the reference beam. The method can be used to for multicolor wavefront reconstructions. The storage capacity of the method depends on the spread of the spectrum in the Fourier transform plane. This can, however, be increased by incorparating an additional periodic modulation in the Fourier transform plane.

• Open/close Effect of temporal coherence on the Fresnel diffraction pattern by slit aperture

  Hitoshi Fujii and Toshimitsu Asakura 1973 Nouvelle Revue d'Optique 4 273 Tag this article

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  A formulation is developed for investigating the effect of temporal coherence of the illumination on the intensity distribution in the Fresnel diffraction field of a slit aperture. The formula derived is applied to actually obtain the intensity distributions both along the axis normal to the slit aperture and in the Fresnel diffraction patterns for various receiving planes parallel to the aperture plane. It is found that the temporal coherence is less effective on the intensity distribution in the Fresnel diffraction field. The theoretical results for Fresnel diffraction patterns of a slit aperture illuminated by partially, temporally coherent light are experimentally confirmed.

• Open/close For infrared spectra of trichydrated potassium ferrocyanide

  F Brehat and A Hadni 1973 Nouvelle Revue d'Optique 4 297 Tag this article

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  The Far Infrared spectrum of hydrated and deuteriated potassium ferrocyanide from 10 to 250 cm ^-1 at 300 and 80 K, Shows the possibility of two crystallographic species at 300 K, one is known as tetragonal, the other as monoclinic and this one gives an additional band at 27 cm ^-1. On the opposite the transformation from the monoclinic paraelectric form to the monoclinic ferroelectric form at 249 K does not show any significant spectral change at the Curie temperature. The effect of deuteriation shows that the 80 K bands observed at 177, 148 et 115 cm ^-1 are due to translational frequencies involving mainly the water molecules, while the bands at 194, 105, 89,5, 82, 69,5, 61, 53,5 et 28 cm ^-1 are due to vibrations where the other components of the lattice are playing the main role.

• Open/close Synthetic apertures: formation of images and improvement of resolving power.

  A Caron 1973 Nouvelle Revue d'Optique 4 337 Tag this article

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  A transposition of various techniques dealing with synthetic apertures and used in Radioastronomy is presented in this paper. The transfer function and resolving power are investigated theoretically and experimentally in two types of distributions of elementary apertures: continuous or segmented square borders (suggested by the Wild's annular aerial array) and the Mills cross. A special apodization efficacious with synthetic apertures is described.