Abstract:
Die Erfindung betrifft optische Messsysteme und optische Messverfahren basierend auf Digital-Holografie zur Messung zumindest einer Komponente der Verformung und/oder Dehnung eines Messobjekts in zumindest einer vorgegebenen oder vorgebbaren Richtung mittels Digital-Holographie. Das optische Messsystem umfasst eine Digital-Holographie Vorrichtung (12, 12-1, 12-2, 12-3) zum Beleuchten eines Abtastbereichs eines Messobjekts, welche eine out-of-plane und/oder eine in-plane Digital-Holographie Anordnung mit zumindest zwei kohärenten Strahlen aufweist, und ein Mikroskopobjektiv (24) dessen optische Achse im Wesentlichen parallel zu einer vertikalen Richtung ist und welches in dem optischen Pfad des zumindest einen Teils des vom Messobjekt (22) reflektierten Lichts angeordnet ist, wobei, wenn gesehen in der vertikalen Richtung, die Digital-Holographie Vorrichtung (12, 12-1, 12-2, 12-3) unterhalb oder oberhalb des Mikroskopobjektivs (24) und/oder eines Mikroskopgrundkörpers angeordnet ist.
Abstract:
An optical interferometer (1) is used to determine information about the position, gradient or motion of a surface of an object (2) at each of a plurality of points on the surface. An image is projected onto the surface of the object (2), such that, for each of the plurality of points, the intensity or spectrum of the projected image at that point depends on the determined information about the position, gradient or motion of the surface at that point.
Abstract:
An interferometer includes an He-Ne laser coupled into a probe part by an optical feed, a beam splitter (14) splitting the beam between a target and a narrow angle scatterer (16). The beam splitter (14) also combines the reflected signals from the target and the scatterer (16) and feeds them to signal conditioning optics (20, 22). The resultant amplified signal is received by a quadrature detector (26, D1-D4) which obtains four detector signals which are subsequently combined to eliminate noise and dc offsets. The combination of narrow angle scatterer (16) and quadrature detector considerably increases resolution and accuracy.
Abstract:
The present invention relates to a device (4) comprising a speckle interferometer part and a microscope part, wherein the speckle interferometer part comprises one or more lasers (5), one or more beam splitters (3), and a piezo mirror (8), and the microscope part comprises at least one tube (2) and a lens (11) arranged at the lower end of the at least one tube (2), wherein at least one beam splitter (3) of the speckle interferometer part is partially or completely integrated in the at least one tube (2) of the microscope part in such a way that the reference beam (6-1) and the object beam (6-2) can be conducted through the lens (11) of the microscope part. The device according to the invention is substantially a microscope that comprises at least one optical component of a speckle interferometer in the tube of the microscope. A substantially more compact construction for speckle interferometer devices is thereby additionally effected, whereby said speckle interferometer devices can be operated even with diode lasers.
Abstract:
A z-movement detector utilises an optical interferometer with a laser diode as a light source (301) and an optical interference detector (302) which detects changes in the speckle pattern of the light from the laser as a result of movements of a target (307) in the z-direction. Key element of the interferometer is the use of a single block of glass (318) which physically integrates the beam splitting functions and some of the reflection functions of the interferometer.
Abstract:
An apparatus for determining a propagation velocity for a surface wave comprises a coherent light source (105) for generating at least a first and a second light spot on a surface (103). A camera (111) captures at least one out-of-focus image of at least a part of the surface (103) comprising the light spots. The out-of-focus image comprises light spot image objects for the light spots where the light spot image objects have speckle patterns. An analyzer (113) determines the propagation velocity in response to a time difference between speckle pattern changes in the two speckle patterns. The camera may specifically use a rolling shutter allowing the determination of the propagation velocity to be based on a spatial analysis of the speckle patterns. The approach may in particular allow an efficient remote measuring of pulse wave velocities e.g. in animal tissue and in particular, in human tissue.
Abstract:
Die vorliegende Erfindung beschreibt eine Vorrichtung (4), umfassend einen Speckle-Interferometer-Teil und einen Mikroskop-Teil, wobei der Speckle-Interferometer-Teil einen oder mehrere Laser (5), einen oder mehreren Strahlenteiler (3) und einen Piezospiegel (8) umfasst, und der Mikroskop-Teil mindestens einen Tubus (2) und ein am unteren Ende des mindestens einen Tubusses (2) angeordnetes Objektiv (11) umfasst, wobei mindestens ein Strahlenteiler (3) des Speckle-Interferometer-Teils teilweise oder vollständig derart in dem mindestens einen Tubus (2) des Mikroskop-Teils integriert ist, dass der Referenzstrahl (6-1) und der Objektstrahl (6-2) durch das Objektiv (11) des Mikroskop-Teils leitbar sind. Die erfindungsgemäße Vorrichtung ist im Wesentlichen ein Mikroskop, welches wenigstens eine optische Komponente eines Speckle-Interferometers in dem Tubus des Mikroskops aufweist. Dadurch wird zusätzlich eine wesentlich kompaktere Bauweise für Speckle-Interferometer-Vorrichtungen bewirkt, wodurch diese selbst mit Diodenlasern betrieben werden können.
Abstract:
An improved method for measuring residual stress in a material comprising the steps of applying a spot of temperature indicating coating to the surface to be studied, establishing a speckle pattern surrounds the spot of coating with a first laser then heating the spot of coating with a far infrared laser until the surface plastically deforms. Comparing the speckle patterns before and after deformation by subtracting one pattern from the other will produce a fringe pattern that serves as a visual and quantitative indication of the degree to which the plasticized surface responded to the stress during heating and enables calculation of the stress.
Abstract:
To improve the contrast of images obtained using the pulsed image-addition ESPI technique and relative to a mechanically stressed object, a preliminary measuring cycle is performed, with the object in the unstressed condition, to obtain a predetermined number of interference images (110-160) differing from one another by a controlled phase shift of a fraction of the pulses traveling along one of the branches of the interferometer; a mean luminous intensity value is calculated (170) from the interference images, is memorized (180), and is subtracted (220) from each of the interference images obtained during the actual measuring cycle to improve the contrast of the images.