Universität Stuttgart
Permanent URI for this communityhttps://elib.uni-stuttgart.de/handle/11682/1
Browse
15 results
Search Results
Item Open Access Testing of aspheric surfaces with computer generated holograms(1988) Tiziani, Hans J.; Packroß, Bernd; Schmidt, GerhardAspherical surfaces are becoming more important and can even be mass producted. There is a need for flexible test methods of high accuracy. The paper describes the combination of a computer generated holograms with a partially compensating lens as a powerful tool. An example for testing a steep aspheric surface will be given.Item Open Access Mikro-Profilometrie zur Bestimmung der Topographie und Rauheit technischer Oberflächen mittels Heterodyn-Laserinterferometrie(1989) Leonhardt, Klaus; Rippert, Karl-Heinz; Tiziani, Hans J.Ein Heterodyn-Profilometer zur Messung der Rauheit polierter und feingeschliffener Oberflächen und zur Formmessung wird beschrieben. Die Vertikal- oder Höhenauflösung liegt bei 0,5 nm, der Meßbereich für Formmessungen an glatten Oberflächen bei 40 pm bei einer maximalen Abtastlänge von 300 mm. Die Lateralauflösung kann je nach Aperturausleuchtung bis zu 0,5 pm eingestellt werden. Anwendungen und Grenzen werden gezeigt, Formeln zur Lateralauflösung und zur Erfassung von Phasensprüngen sowie Profilhöhen-Übertragungsfunktionen werden diskutiert.Item Open Access Optical methods of measuring rough surfaces(1989) Leonhardt, Klaus; Rippert, Karl-Heinz; Tiziani, Hans J.The statistical parameters of surfaces to be measured for industrial applications vary over several orders of magnitude. Surfaces with large slopes or edges are particularly difficult to be recorded. Some measuring methods developed in our laboratory are compared and the range of applications are discussed. For polished and fine ground glass and metal surfaces a heterodyne profilometer with a vertical resolution of 0.5 nm, lateral resolution of 0.6 μm, and large scanning length is discussed. The interferometer can be changed from single- to double-pass operation by rotation of a quarter-wave-plate. For rougher surfaces a profilometer of the photometric-balance type with resolution Rq < 4 nm and dynamic range of 20 μm and an interference microscope with automated fringe evaluation is described. An integral white light roughness sensor covers the roughness range 0.04μm to 10μm and measures independently mean roughness and autocorrelation width.Item Open Access Meeting the optical talent needs of industry in Europe(1989) Tiziani, Hans J.The thematic "meeting the optical talent needs of industry in Europe" can be looked at from different points of view. In the present report the industrial activities and the education in optics are summarized. My colleagues of the "Institut d'Optique" in Paris and the Imperial College in London will report on the curriculum in optics in Paris and London. The emphasis is more on the model we use at the University of Stuttgart. It is a particular engineering curriculum forming engineers with a good optics background.Item Open Access Verfahren zur optischen Rauheitsmessung und Mikroprofilometrie(1985) Leonhardt, Klaus; Rippert, Karl-Heinz; Tiziani, Hans J.In diesem Beitrag werden wegen der Kürze der Darstellung nur einige der bekannten Verfahren behandelt. Zwei Verfahren der Mikroprofilometrie, die im Institut für Technische Optik Stuttgart zur Zeit bearbeitet werden und ein Verfahren der integralen Rauheitsmessung, das in unserem Institut entwickelt wurde, werden ausführlicher beschrieben.Item Open Access New light valve based in photoinduced space charge fields in BSO-crystals(1987) Tiziani, Hans J.; Höller, FrankThe combined photoelectric and electrooptic properties of the BSO-crystal lead to a new possibility of realizing a real time spatial light modulator. Under certain geometrical conditions the crystal becomes birefringent in dependence on the local illuminance. Together with a suitable polarizer setup the crystal works as well as an incoherent to coherent converter as for contrast inversion.Item Open Access Remote nondestructive material analysis by photothermal interferometry(1987) Sodnik, Zoran; Tiziani, Hans J.Interferometry is used for the detection of thermal waves to study material properties. A symmetrical interferometer as thermal expansion detector was developed for photothermal nondestructive material analysis. After mixing a phase shifted reference signal electrically to the interferometer signal, phase and amplitude exchange phenomena have been observed.Item Open Access Optical methods in engineering measurements(1986) Tiziani, Hans J.The optical precision measurement methods described in this paper have resolutions in the range from A to a few microns. To extend the range structured light techniques or optical triangulation,can be used in metrology. The application of interferometry and holography will be extended because of the progress made in the fringe analysis. New coherent light sources together with real-time storage devices will lead to further progress in the application of optical techniques in industry.Item Open Access Modulation transfer function obtained from image structures(1989) Lei, Fang; Tiziani, Hans J.A new and relatively simple method for edge gradient analysis (EGA) has been developed to determine the modulation transfer function (MTF) of photogrammetrical systems. The MTF can be calculated as the ratio of the amplitude of those frequencies present in the original edge to the amplitude of the same frequency in the scanned edge image. Thus a differentiation of the edge scan - as usually implemented - is not necessary. In order to avoid a division by zero we multiplied the edge images by the so called Hanning function before performing the Fourier analysis. From the point of noise sensitivity the method using a Hanning window is advantageous in comparison to the edge differentiation method. The edge gradient analysis method and the grating pattern method are compared. Artificial edge, natural roof edge, and grating patterns were used to determine the quality of the photogrammetrical system. Good agreement of all MTF measurements was found. Furthermore, the resolution found from MTF curves agreed well with the resolution obtained from threebar targets. Generally, the MTF curves obtained from patterns in the flight direction were lower than the MTF's perpendicular to the flight direction due to airplane movement. The influence of linear image motion and its compensation was examined and is discussed. Furthermore, the longitudinal motion of the object as defect of focus is studied analytically and experimentally for a close range.Item Open Access Fringe analysis in holography with BSO applications(1988) Tiziani, Hans J.Progress has been made in the fringe analysing procedures. At last interferometry, holography and speckle techniques are more frequently applied in industry and become a powerful tool for engineering applications. The methods will be even more frequently applied in industry, when they can be applied in real time. In speckle interferometry the speckle size can be adapted to the photoelectric detector. In nondestructive testing with holographic or speckle techniques, in addition to the automatic fringe analysis the computation of the corresponding deformation and strain needs to be further improved. Furthermore, real time storage materials, rugged and reliable lasers and holographic components are needed to make the holographic methods for nondestructive testing even more attractive for the industry.