摘要:
In the method for creating colour patterns for technical applications and visible for the human eye by means of diffraction gratings through light irradiation, diffraction grating arrays are produced directly on a solid body surface in a laser microstructuring process by at least one laser installation in the nanosecond range or in the pico- or femtosecond range, each diffraction grating array being composed of subareas (81) whose longitudinal dimension has a value below the resolving ability of the eye and which contain at least one pixel (81, 82, 83), a pixel being a limited diffraction grating structure for producing a spectral colour. The direct application of such colour-producing diffraction grating structures to a solid body surface enables a large variety of decorative and authentication possibilities ranging from embossing tools to jewellery.
摘要:
Beim Verfahren zur Erzeugung von für technische Anwendungen und für das menschliche Auge sichtbaren Farbmustern mittels Beugungsgitter durch Lichtbestrahlung werden Beugungsgitter-Arrays durch Lasermikrostrukturierung mit mindestens einer Laseranlage im Nanosekunden-Bereich oder im Piko- oder Femtosekunden-Bereich direkt auf einer Festkörperoberfläche erzeugt, wobei jede Beugungsgitter-Array aus Subflächen (81) besteht, deren Längenerstreckung einen Wert unterhalb des Auflösungsvermögen des Auges aufweist und die mindestens ein Pixel (81, 82, 83) enthält, wobei ein Pixel eine begrenzte Beugungsgitterstruktur zur Erzeugung einer Spektralfarbe ist. Durch das direkte Aufbringen solcher farberzeugender Beugungsgitterstrukturen auf eine Festkörperoberfläche wird eine grosse Vielfalt von Dekorations- und Authentifizierungsmöglichkeiten eröffnet, die von Prägewerkzeuge zu Schmuckstücken reicht.
摘要:
The invention relates to an interferometric method in which the sample light which is scattered by an object is imaged onto an electronic camera, wherein a sample light portion is assigned to scattering locations on a sectional face in the interior of the object. This sample light portion can be separated from the contributions of the other sample light portions by processing the camera image, and gives rise to a sectional image. A particular advantage of the invention is that a plurality of sectional faces running in parallel at predetermined distances from one another in the interior of the object can be exposed one after another. Such a sequence of sectional images can be used to calculate a volume model of the object. The invention can be applied, in particular, to the living retina and permits a three-dimensional retina scan within several seconds using a cost-effective and, under certain circumstances, hand-held device. Application possibilities are ophthalmology and biometry.
摘要:
The invention relates to a method for holographic analysis of a sample (111) including a particle of interest (112A), said sample being arranged between a light source (120) and an optical system (131), and said method including the following steps: defining a reference point (118) located on an interface (116, 117) of the sample, or at a known distance from said interface; positioning the object plane (133) of the optical system at a controlled distance D1 from the reference point, the particle of interest (112A) being located outside of said object plane (133); acquiring a transmission holographic image of the sample; digitally reconstructing images, each of which is associated with a predetermined virtual offset (Dii) of the object plane along the optical axis; and deriving the distance (D F ) between the particle of interest and the reference point.
摘要:
An apparatus for holographic imaging consists of a pulsed laser beam source (1) and an optical assembly which splits the beam into an object beam (3, 3') and a reference beam (4, 4'). The object beam (3') is directed to illuminate an object and the reference beam (4') is directed onto a photorefractive crystal (8). The photorefractive crystal (8) and the object (7) are located so that light reflected from the object forms an interferogram in a plane in which the crystal (8) is located. A CCD camera (9) is disposed to view the crystal (8) and thus to transform the interferogram which is temporarily recorded on the crystal (8) into electrical signals which can then be recorded for subsequent processing in the electronic memory of a data processing system (11). The camera (9) and crystal (8) can be mounted on a carriage (10) so that the crystal (8) can be scanned through the interferogram and the elements of an interferogram larger than the crystal (8) recorded electronically as a sequence of frames.
摘要:
In the interferometric system, the image plane 3.3 of an imaging setup 3.1 of an object branch is imaged by means of an output imaging setup 4 via a transmission system 6.1 of reflectors to the output plane 7 and simultaneously in the image plane 3.4 of an imaging setup 3.2 of a reference branch is a reflection type diffraction grating 5 located, which is imaged by the output imaging setup 4 via a transmission system 6.2 of reflectors also to the output plane 7 of the interferometer where an achromatic off-axis hologram is formed by the interference of waves coming from both the object branch and the reference branch and where a detector is located. The transmission systems of reflectors 6.1 and 6.2 are adjusted in such a way that axes of both branches coincide at an entrance to the output plane 7 and they are parallel with a normal line of the output plane 7, and an axial beam, diffracted by the reflection type diffraction grating 5 at an angle α, enters into the output plane 7 at an angle β, and the relation between angle β and α is sin(β) = sin(α)/m, where m is a magnification of the output imaging setup 4. The system enables the achievement of a holographic imaging of an object by means of low-coherence waves, e.g. white light from an extended light source. Incoherent waves allow the imaging of objects immersed in scattering media. The imaging is carried out in real time. It is possible to use a single digitally recorded hologram of a part of the observed object and numerically reconstruct the object wave, it means its intensity and phase. Intensity imaging is depth discriminated; therefore it represents a cross-section through the observed sample. The cross-section thickness depends on a degree of coherence of the used waves and, if light microscopy is considered, it can be narrower than an optical cross-section obtained by a confocal microscope. The phase image corresponds to the difference of times of propagation through the object and the reference branches caused by the observed sample, it is quantitative and may be used for measuring a depth of reflective samples with accuracy in orders of thousandths of a wavelength, or, for example, in case of transmitted-light microscopic imaging, it can be used to weigh cells or to analyze an intracellular mass movement.
摘要:
Capteur (100, 200) pour la détection à distance d'un objet, comportant - une source lumineuse (110), ayant une longueur de cohérence faible par rapport à la distance entre le capteur et l'objet ; - un séparateur (112), divisant le faisceau lumineux émis en un faisceau incident (126) et un faisceau de référence (123) ; - un cristal photoréfractif (114) enregistrant un hologramme à la réception interférante du faisceau de référence (123) et du faisceau réfléchi (127) par un objet (120) illuminé par le faisceau incident (126), et restituant l'hologramme dans un faisceau diffracté (124) réémis par le cristal par diffraction anisotrope sous l'effet du faisceau de référence (123), - un détecteur (116), enregistrant une information à réception du faisceau diffracté (124) ; - un filtre par polarisation (115), éliminant la plus grande partie du faisceau réfléchi transmis (128) par le cristal à réception du faisceau réfléchi; ainsi, le détecteur (116) ne reçoit du cristal que le faisceau diffracté (124).Ce capteur, et les systèmes d'imagerie intégrant ce capteur permettent la réalisation de mesures à travers des milieux diffusants.
摘要:
Un dispositif servant à la formation d'images holographique est constitué par une source de faisceaux laser pulsés (1) et par un ensemble optique divisant ledit faisceau en un faisceau d'objet (3, 3') et en un faisceau de référence (4, 4'). Le faisceau d'objet (3') est dirigé de façon à éclairer un objet et le faisceau de référence (4') est dirigé vers un cristal photoréfringent (8). Le cristal photoréfringent (8) et l'objet (7) sont placés de manière que la lumière réfléchie par l'objet forme un interférogramme dans un plan dans lequel est situé le cristal (8). Une caméra à dispositif à couplage de charge (CCD) (9) est située de façon à visualliser le cristal (8) et, de ce fait, à transformer l'interférogramme enregistré temporairement sur le cristal (8) en signaux électriques pouvant être ensuite enregistrés, afin d'être traités ultérieurement dans la mémoire électronique d'un système de traitement de données (11). La caméra (9) et le cristal (8) peuvent être montés sur un chariot (10), de façon à explorer le crystal (8) à travers l'interférogramme, ainsi qu'à enregistrer électroniquement, en tant que séquence d'images, les éléments d'un interférogramme supérieur au cristal (8).