摘要:

Various optical data-processing techniques are reviewed in this article. Both coherent and incoherent optical systems are considered. Coherent systems are described in terms of spatial filtering concepts and two principal methods for implementing a general linear integral operator are discussed: one using space-domain reference function masks and one using frequency-domain spatial filters. Incoherent systems are described in terms of geometrical optics.

ISSN:0030-3909    

DOI:10.1080/713818057

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

The effects of multiple frequencies in spatially recording two wavefronts are analysed to describe the fringes recorded in holography as a function of the number of frequencies used, and to relate the changes in the fringe structure to the quality of the reconstructed image. The analysis is applicable to spatial filtering or to any process where a coherent wavefront is recorded by interference with another wavefront. A possibility of doppler shift of the frequencies in one wave is included to describe the effects of recording a hologram of a moving object. It is shown that, if the multiple frequencies are due to laser multimoding, the fringe visibility is a maximum for path differences equal to even multiples of the laser cavity length, but that the locations of the minima depend upon the relative amplitudes of the different frequencies. The effects of the changes in the fringe structure upon the resulting image or correlation are discussed.

ISSN:0030-3909    

DOI:10.1080/713818055

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

Es werden die bisher in der Literatur angegebenen Methoden zur Bestimmung der Aberrationen des Auges besprochen. Es zeigt sich dabei, dass unter schiedliche Verfahren nicht nur mit unterschiedlicher Genauigkeit arbeiten, sondern auch prinzipiell verschiedene Ergebnisse für ein und denselben Fall liefern können. Wir schlagen vor beim Auge nach Helmholtz statt von sphärischer von monochromatischer Aberration zu sprechen. Das Koinzidenzprinzip, sowie ein nach diesem Prinzip gebautes Gerät werden eingehend beschrieben. An je einem Messbeispiel wird die Abhängigkeit der monochromatischen Aberration von der Akkommodationslage (bei 0,3; 1,3 und 2,3 dpt) und von der Wellenlänge (bei 5 Wellenlängen) gezeigt. Zum Abschluss werden die Grenzen der Messgenauigkeit diskutiert.

ISSN:0030-3909    

DOI:10.1080/713818061

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

Given a wavefront with rotational symmetry, it is possible to calculate the interferogram that would be obtained in a lateral shearing interferometer. The opposite problem, that is, to find the wavefront from measurements on the interferogram, is also discussed.

ISSN:0030-3909    

DOI:10.1080/713818060

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

In an earlier paper, results were reported of the effects of partial coherence on the phase contrast images of phase objects when the source was (i) circular and centred on the axis, and (ii) annular. In the first part of this paper, some further results obtained with the circular source being shifted away from the axis are presented. Further, extension is made to introduce a second similar source placed symmetrically about the axis. This second source may either (i) be completely incoherent with respect to the first one or (ii) have a point-to-point coherence. The effects of partial coherence are studied for both the above cases. In the second part of the paper, images of more general but periodic phase objects have been considered. Results for singly periodic and square-topped phase gratings are presented for axial full-cone and annular illumination.

ISSN:0030-3909    

DOI:10.1080/713818058

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

Some misconceptions concerning Babinet's principle are pointed out. The Fraunhofer diffraction patterns of complementary screens are not similar unless the detail in the screens obeys certain conditions, which are not easily fulfilled. Some examples of the diffraction patterns of complementary screens are given, illustrating the extent to which Babinet's principle is valid in practice. A way in which the principle can be used to give the diffraction patterns of three-dimensional crystal-structure models is indicated.

ISSN:0030-3909    

DOI:10.1080/713818059

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

In der nachfolgenden Mitteilung werden fortschreitende Wellen, die der Wellengleichung genügen, mit Potentialfunktionen verknüpft. Dadurch gelingt es, Bedingungen für einen Übergang von der Strahlen- zur Wellenoptik nachzuweisen. Dieser Nachweis erlaubt die Übertragung von Ergebnissen der Potentialtheorie auf die Optik. Als eine Folgerung läßt sich ein Satz über die Analytizität des Eikonals aussprechen, durch den eine Rechtfertigung für die Reihenentwicklungen der Eikonalfunktionen gegeben ist.

ISSN:0030-3909    

DOI:10.1080/713818056

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor