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Shao, Y. (author), Loktev, Mikhail (author), Tang, Y. (author), Bociort, F. (author), Urbach, Paul (author)For advanced imaging systems, e.g., projection systems for optical lithography, spatially varying aberration calibration is of utmost importance to achieve uniform imaging performance over the entire field-of-view (FOV). Here we present an efficient, accurate, and robust spatially varying aberration calibration method using a pair of 2...journal article 2019
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Mout, B.M. (author), Flesch, Andreas (author), Wick, Michael (author), Bociort, F. (author), Petschulat, Joerg (author), Urbach, Paul (author)The electric field at the output of an optical system is in general affected by both aberrations and diffraction. Many simulation techniques treat the two phenomena separately, using a geometrical propagator to calculate the effects of aberrations and a wave-optical propagator to simulate the effects of diffraction. We present a ray-based...journal article 2018
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Hou, Z. (author), Nikolic, Milena (author), Benitez, Pablo (author), Bociort, F. (author)Traditional imaging design methods can often be ineffective when designing aspheric systems because of the large number of optimization parameters and lack of a good starting point. They are often trapped in a poor local minimum and it can be highly time-consuming to find a good solution in a bumpy design landscape. The simultaneous multiple...journal article 2018
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Mout, B.M. (author), Wick, Michael (author), Bociort, F. (author), Petschulat, Joerg (author), Urbach, Paul (author)We study a simulation method that uses the Wigner distribution function to incorporate wave optical effects in an established framework based on geometrical optics, i.e., a ray tracing engine. We use the method to calculate point spread functions and show that it is accurate for paraxial systems but produces unphysical results in the presence...journal article 2018
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Strauch, M. (author), Somers, P.A.A.M. (author), Bociort, F. (author), Urbach, Paul (author)A technique to create aspheric surface shapes on commercially available electrowetting liquid lenses is demonstrated. Based on a previously published surface oscillation model a technique using a Hankel transform is proposed and tested experimentally. An alternating actuation voltage is applied to the liquid lens to stimulate surface...journal article 2018
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Strauch, M. (author), Shao, Y. (author), Bociort, F. (author), Urbach, Paul (author)The increased usage of liquid lenses motivates us to investigate surface waves on the liquid's surface. During fast focal switching, the surface waves decrease the imaging quality. We propose a model that describes the surface modes appearing on a liquid lens and predicts the resonance frequencies. The effects of those surface modes on a...journal article 2017
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Mout, B.M. (author), Wick, Michael (author), Bociort, F. (author), Petschulat, Joerg (author), Urbach, Paul (author)We present a method for simulating multiple diffraction in imaging systems based on the Huygens–Fresnel principle. The method accounts for the effects of both aberrations and diffraction and is entirely performed using Monte Carlo ray tracing.We compare the results of this method to those of reference simulations for field propagation through...journal article 2016
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Mout, B.M. (author), Wick, M. (author), Bociort, F. (author), Urbach, H.P. (author)The Wigner Distribution Function (WDF) forms an alternative representation of the optical field. It can be a valuable tool for understanding and classifying optical systems. Furthermore, it possesses properties that make it suitable for optical simulations: both the intensity and the angular spectrum can be easily obtained from the WDF and the...conference paper 2015
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Hou, Z. (author), Bociort, F. (author)A major challenge in lens design is the presence of many local minima in the optimization landscape. However, unlike other global optimization problems, the lens design landscape has an additional structure, that can facilitate the design process: many local minima are closely related to minima of simpler problems. For discussing this property,...conference paper 2015
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Strauch, M. (author), Livshits, I.L. (author), Bociort, F. (author), Urbach, H.P. (author)We show that wide-angle spectral imaging can be achieved with compact and cost-effective devices using Fabry-Pérot interferometers. Designs with a full field of view of 90°, in which the Fabry-Pérot interferometer is mounted either in front of an imaging lens system or behind a telecentric lens system, are presented and analysed. We show the...journal article 2015
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Bociort, F. (author), van Grol, P. (author)Understanding the structure of the design space in optical system optimization is difficult, because common human intuition fails when it encounters the challenge of high dimensionality, resulting from the many optimization parameters of lens systems. However, a deep mathematical idea, that critical points structure the properties of the space...conference paper 2012
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Polo, A. (author), Kutchoukov, V. (author), Bociort, F. (author), Pereira, S.F. (author), Urbach, H.P. (author)We apply a phase retrieval algorithm to the intensity pattern of a Hartmann wavefront sensor to measure with enhanced accuracy the phase structure of a Hartmann hole array. It is shown that the rms wavefront error achieved by phase reconstruction is one order of magnitude smaller than the one obtained from a typical centroid algorithm....journal article 2012
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Mu, C. (author), Cornelissen, H.J. (author), Bociort, F. (author), Liebig, T. (author)A new approach is described to couple light from high-power blue LEDs (1x1mm2) into a thin large area light guide using a dielectric interference multilayer as an angular filter. The goal is to achieve large area luminaires such as backlight systems. The method overcomes the drawback of structuring holes or recessions in light guides when using...conference paper 2011
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Bociort, F. (author), Van Grol, P. (author)In this paper we describe new properties of the design landscape that could lead in the future to a new way to determine good starting points for subsequent local optimization. While in optimization the focus is usually only on local minima, here we show that points selected in the vicinity of other types of critical points (i.e. points where...conference paper 2010
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Bociort, F. (author)The presence of many local minima in the merit function landscape is perhaps the most difficult challenge in lens design. We present a simplified mathematical model that illustrates why the number of local minima increases rapidly with each additional lens added to the imaging system. Comparisons with results obtained with lens design software...conference paper 2010
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Bociort, F. (author), Van Grol, P. (author)In this paper we describe new properties of the design landscape that could lead in the future to a new way to determine good starting points for subsequent local optimization. While in optimization the focus is usually only on local minima, here we show that points selected in the vicinity of other types of critical points (i.e. points where...conference paper 2010
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Van Grol, P. (author), Bociort, F. (author), Van Turnhout, M. (author)Contrary to the frequent tacit assumption that the local minima of a merit function are points scattered more or less randomly over the design landscape, we have found that, at least for simple imaging systems (doublets with three and triplets with five variables) all design shapes we have observed thus far form a strictly ordered set of points,...conference paper 2009
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- Bociort, F. (author), Van Turnhout, M. (author) journal article 2009
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Van Turnhout, M. (author), Bociort, F. (author)In lens design, damped least-squares methods are typically used to find the nearest local minimum to a starting configuration in the merit function landscape. In this paper, we explore the use of such a method for a purpose that goes beyond local optimization. The merit function barrier, which separates an unsatisfactory solution from a...journal article 2009
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Van Turnhout, M. (author), Bociort, F. (author)Many optical design programs use various forms of the damped least-squares method for local optimization. In this paper, we show that damped least-squares algorithms, with maximized computational speed, can create sensitivity with respect to changes in initial conditions. In such cases, starting points, which are very close to each other, lead...journal article 2009