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document
Houtman, E.M. (author), Bannink, W.J. (author), Timmerman, B.H. (author)
report 1995
document
Nijholt, J.L.M. (author)
This book describes the theoretical design of a three camera Michelson interferometer set-up for quantitative refractive index measuerments. Although a two camera system is easier to align and less expensive, a three camera interferometer is preferred because the expected measuring accuracy is much better. Here analytical expressions are found...
book 1998
document
Krieg, M.L. (author), Braat, J.J.M. (author)
This paper will illustrate several approaches to retrieving the shape of aspherical reflective surfaces as used in EUV Lithography, from measurements from a previously reported angstrom-accuracy interferometer. First, the working principles of the interferometer will be reviewed, and typical measurement data expected from the instrument will be...
conference paper 2004
document
Van der Avoort, C. (author), Mieremet, A. (author), Pereira, S. (author), Braat, J. (author)
We present results of experiments obtained using a new nulling technique that enables deep nulling without the use of achromatic phase shifters. The experimental set-up consists of a three-beam interferometer that should provide a nulling depth of several thousands over a wavelength range of 500 to 650 nm. The intended depth of null was not...
conference paper 2004
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Van der Avoort, C. (author), Van Brug, H. (author), Den Herder, J.W. (author), d'Arcio, L. (author), Le Poole, R. (author), Braat, J. (author)
Homothetic mapping is an aperture synthesis technique that allows interferometric imaging over a wide fieldof-view. A laboratory experiment was set up to demonstrate the feasibility of this technique. Here, we present the first static experiments on homothetic mapping that have been done on the Delft Testbed for Interferometry (DTI). Before a...
conference paper 2004
document
Montilla, I. (author), Pereira, S.F. (author), Braat, J.J.M. (author)
Wide field interferometry has become a subject of increasing interest in the recent years. New methods have been suggested in order to avoid the drawbacks of the standard wide field method (homothetic mapping) which is not applicable when the aperture is highly diluted; for this reason imaging with non-homothetic arrays is being extensively...
conference paper 2004
document
Montilla, I. (author)
The main goal of this thesis is to develop a system to permit wide field operation of Michelson Interferometers. A wide field of view is very important in applications such as the observation of extended or multiple objects, the fringe acquisition and/ or tracking on a nearby unresolved object, and also to reduce the observation time. For ground...
doctoral thesis 2004
document
Krieg, M.L. (author)
For the past thirty years, microchips have doubled in complexity every two years. This increasing complexity required that the size of the structures written on silicon halve at the same rate. A fundamentally limiting factor to the size of microchip structures is the wavelength of the lithographic projection processes used in their manufacture....
doctoral thesis 2004
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Montilla, I. (author), Pereira, S.F. (author), Braat, J.J.M. (author)
A new interferometric technique for Michelson wide-field interferometry is presented that consists of a Michelson pupil-plane combination scheme in which a wide field of view can be achieved in one shot. This technique uses a stair-shaped mirror in the intermediate image plane of each telescope in the array, allowing for simultaneous correction...
journal article 2005
document
Soloviev, O. (author), Vdovin, G. (author)
We propose an algorithm for phase retrieval from three interferograms which differ only by an arbitrary unknown tilt terms in the phase. The method is illustrated by examples.
conference paper 2005
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Krieg, M.L. (author), Braat, J.J.M. (author)
A previously reported interferometer without intermediate optics is used to perform measurements on an aspherical extreme ultraviolet lithography mirror substrate. Acousto-optic modulation based phase shifting is used together with a novel phase retrieval algorithm to retrieve the phase distribution from our interferograms. The phase...
conference paper 2005
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Soloviev, O. (author), Vdovin, G. (author)
This article presents a prototype of a CMOS phase sensor for high accuracy (1 Angstrom) heterodyne interferometry. Switched integrators realization of a lock-in pixel for 4-bucket phase detection algorithm is described and illustrated by experimental results. Factors that limit the accuracy of this implementation and possible ways for its...
conference paper 2005
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Van der Avoort, C. (author), Den Herder, J.W. (author), Braat, J. (author)
This paper compares two well-known types of interferometer arrays for optical aperture synthesis. An analytical model for both types describes the expected output, in terms of photon counts. The goal is to characterize the performance of both types of array for blind imaging of a wide-field or extended object that would be partially resolved by...
conference paper 2005
document
Swinkels, B.L. (author), Bhattacharya, N. (author), Braat, J.J.M. (author)
Absolute distance measurements can be performed with an interferometric method that uses only a single tunable laser. This method has one major drawback, because a small target movement of the order of one wavelength during a measurement will be interpreted as a movement of one synthetic wavelength. This effect is usually mitigated by adding a...
journal article 2005
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Spronck, J. (author), Pereira, S.F. (author), Braat, J.J.M. (author)
We introduce the concept of chromatism compensation in nulling interferometry that enables a high rejection ratio in a wide spectral band. Therefore the achromaticity condition considered in most nulling interferometers can be relaxed. We show that this chromatism compensation cannot be applied to a two-beam nulling interferometer, and we make...
journal article 2006
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Spronck, J. (author), Pereira, S.F. (author), Braat, J.J.M. (author)
We introduce a new concept of nulling interferometer without any achromatic device, using polarization properties of light. This type of interferometer should enable a high rejection ratio in a theoretically unlimited spectral band. We analyze several consequences of the proposed design, notably, the possibility of fast internal modulation.
journal article 2006
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Spronck, J. (author), Pereira, S.F. (author), Braat, J.J.M. (author)
We discuss the previously-reported measurements of a three-beam nulling interferometer without achromatic phase-shifters, using delay lines only. The theoretical rejection ratio of a few thousand has not been achieved experimentally. In order to explain the obtained results, some direct spectral and polarization measurements have been performed....
conference paper 2006
document
Spronck, J. (author), Pereira, S.F. (author), Braat, J.J.M. (author)
We present a new type of nulling interferometer that makes use of polarization properties to have on-axis destructive interference. The proposed design, which only involves commercial components and no achromatic device, is also suitable for internal modulation. This type of interferometer should enable a high rejection ratio in a theoretically...
conference paper 2006
document
Soloviev, O.A. (author)
The wavefront measurement is an important part both in adaptive optics and in optical shop testing. A number of wavefront sensors based on interferometric or on Hartmann principle is known; this thesis investigates particular technologies that can help to increase the accuracy and/or speed of existing wavefront sensors either by optimising the...
doctoral thesis 2006
document
Draganov, D.S. (author), Wapenaar, C.P.A. (author), Thorbecke, J.W. (author)
In 1968, Jon Claerbout showed that the reflection response of a 1D acoustic medium can be reconstructed by autocorrelating the transmission response. Since then, several authors have derived relationships for reconstructing Green's functions at the surface, using crosscorrelations of (noise) recordings that were taken at the surface and that...
journal article 2006
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