Universität Stuttgart

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Open Access
Zukunft der Optik
(1970) Tiziani, Hans J.
Die Optik hat in den letzten Jahren neuen Aufschwung genommen. Mitverantwortlich für diese Entwicklung sind sowohl die Verwendung von leistungsfähigen Computern als auch die Nachfrage nach immer besserer Auflösung und Bildqualität. Besonders positiv haben sich die Entwicklungen des Laser (1960) und der Holographie ausgewirkt. Immer neue Applikationen des gebündelten, kohärenten Laserlichtes werden erschlossen, doch will ich mich in diesem Zusammenhang auf die mögliche Weiterentwlckung der erwähnten Gebiete beschränken.
Open Access
A study of the use of laser speckle to measure small tilts of optically rough surfaces accurately
(1972) Tiziani, Hans J.
A new method is proposed where small tilts can be measured with high accuracy even in the presence of a lateral shift. For this purpose the speckling of the object, an optically rough surface, is recorded in the Fourier plane before and after a tilt. By illuminating the developed plate with a laser, fringeswith spacings inversely proportional to the tilt angle can be observed.
Open Access
Einige Bemerkungen zur holographischen Meßmethode der optischen Übertragungsfunktion
(1972) Tiziani, Hans J.; Aemmer, Adolf H.
Die holographische Methode zur Messung optischer Übertragungslfunktionen, 1966 postuliert, wird von einer plankonvexen Linse, die nach den Spezifikationen der 50 mm TestIinse der "SIRA" hergestellt wurde, untersucht. Vor allem wird der Einfluß von Fehlerquellen wie mechanische Instabilitäten und Nichtlinearität der Transparenzfunktion der Photoplatte analysiert. Es werden die experimentell gewonnenen Resultate mit berechneten Funktionen verglichen, die simulierte Abweichungen enthalten.
Open Access
Opto-electronic pattern recognition system
(1970) Tiziani, Hans J.; Beyeler, Bernhard H.; Witz, Werner
An opto-electronic technique for the classification of grains of photographic emulsions by shape is described. Fortunately, the shapes to be distinguished differ only in their two-dimensional rotational symmetry group. A special optical filtering procedure has been developed to take account of the implied positional and rotational invariance. The transfer from the optical to the electrical signal is obtained in a simple manner. The method works satisfactorily even for a rather complicated cluster. Some results are discussed.
Open Access
Speckling in diffraction patterns and optical images formed with the laser
(1970) Hopkins, Harold H.; Tiziani, Hans J.
It has been shown that the known characteristics of speckling in both diffraction patterns and optical images can be explained on the basis of a simple physical model. This explains not only the occurence of a predominant size but also the high contrast in speckle patterns.
Open Access
Die optische Ühertragungsfunktion von dezentrierten optischen Systemen
(1976) Beyeler, Bernhard H.; Tiziani, Hans J.
Der Einfluß von Fabrikationsfehlern, unter spezieller Berücksichtigung von Zentrierfehlern, auf die optische Übertragungsfunktion, wird diskutiert. Dabei wird mit Hilfe der Störungsrechnung für kleine Dezentrierungen die Änderung der Wellenfront und damit die entsprechende Abweichung der OTF bestimmt. Daraus folgt eine relativ einfache Abschätzung der zulässigen Toleranzen. Die vorgestellten experimentellen Ergebnisse bestätigen die theoretischen Studien.
Open Access
Prospects of testing aspheric surfaces with computer-generated holograms
(1981) Tiziani, Hans J.
For testing aspheric surfaces, computer generated holograms are frequently used. Some methods of generating the holograms as well as a comparison of in-line and off-axis computer generated holograms will be discussed. Furthermore, examples tested will be analysed from the stand point of an industrial testing procedure.
Open Access
Analysis of mechanical oscillations by speckling
(1972) Tiziani, Hans J.
The application of the speckle phenomenon to the analysis of in-plane translations and oscillations is first reviewed briefly. Then a practical method of investigating out-of-plane rotations (tilts) even in the presence of in-plane movements is studied. This goal can be achieved by recording the speckle patterns in the Fourier transform plane before and after the tilt or as a time-average exposure for an oscillating object. Young’s fringes related to the tilts are observed in the Fraunhofer diffraction pattern when the developed photographic plate is illuminated with coherent light. This leads to a very simple engineering tool for the analysis of movements. Theoretical and experimental results will be shown.
Open Access
Determination of average roughness and profile autocorrelation width of metallic surfaces with a white light sensor
(1984) Leonhardt, Klaus; Kaufmann, Ekkehart; Tiziani, Hans J.
A new procedure to determine simultaneously a horizontal descriptor of the surface - the autocorrelation width - and the most important vertical descriptor - the root-mean-square roughness - is presented. It is based on the inversion of an analytic contrast formula. After a short introduction to white light random phase contrast measurement we describe the elimination process and show first experimental verifications.
Open Access
Vibration analysis and deformation measurement
(1978) Tiziani, Hans J.
It appears that speckle techniques for deformation measurement and vibration analysis will be developed further. The results obtained are generally easy to interpret, compared with those from holographic interferometry, and the mathematics involved is not difficult. Finally, the equipment necessary for laser speckle photography is not unduly complicated.

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