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de Groot, Sjoerd (author)The goal of this thesis is to present a framework which can be used to optimize the observer and controller performance by placement of sensors and actuators on a continuous domain. The framework provides choices of model structure, cost functions and optimization methods to perform the placement. Systems which would be suitable for the use of...master thesis 2018
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Coroli, Iurie (author)When acquiring information using imaging techniques, one wants to achieve the best possible resolution in order to obtain valuable results. In the ideal scenario the size of the smallest resolved object features is limited by the wave properties of light, with a number of techniques developed to overcome this limit. In real life measurements the...master thesis 2018
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Wilding, D. (author)The goal of this thesis, called Physical and Computational Approaches to Aberration Correction In Fluorescence Microscopy, concerns itself with the development of new techniques to control adaptive fluorescence microscopes, so that they can adapt and image with increased resolution, contrast and speed inside complex three-dimensional biological...doctoral thesis 2018
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Rozene Vallespín, Alejandro (author)The resolution of ground-based telescopes is limited by the blurring caused by Earth’s turbulent atmosphere. Adaptive Optics (AO) is a technique used to correct atmospheric distortions, restoring images to diffraction-limited resolution. The main element of an AO system is the Deformable Mirror (DM), which compensates the distortions of the...master thesis 2018
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Quintavalla, M. (author), Pozzi, P. (author), Verhaegen, M.H.G. (author), Bijlsma, H.K. (author), Verstraete, H.R.G.W. (author), Bonora, S. (author)Adaptive Optics (AO) has revealed as a very promising technique for high-resolution microscopy, where the presence of optical aberrations can easily compromise the image quality. Typical AO systems however, are almost impossible to implement on commercial microscopes. We propose a simple approach by using a Multi-actuator Adaptive Lens (MAL)...conference paper 2018
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Wilding, D. (author), Pozzi, P. (author), Soloviev, O.A. (author), Vdovin, Gleb (author), Verhaegen, M.H.G. (author)In life sciences, interest in the microscopic imaging of increasingly complex three dimensional samples, such as cell spheroids, zebrafish embryos, and in vivo applications in small animals, is growing quickly. Due to the increasing complexity of samples, more and more life scientists are considering the implementation of adaptive optics in...conference paper 2018
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Pozzi, P. (author), Wilding, D. (author), Soloviev, O.A. (author), Vdovin, Gleb (author), Verhaegen, M.H.G. (author)In this work, we present a new confocal laser scanning microscope capable to perform sensorless wavefront optimization in real time. The device is a parallelized laser scanning microscope in which the excitation light is structured in a lattice of spots by a spatial light modulator, while a deformable mirror provides aberration correction and...conference paper 2018
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Wilding, D. (author), Pozzi, P. (author), Soloviev, O.A. (author), Vdovin, Gleb (author), Fiolka, Reto (author), Verhaegen, M.H.G. (author)The light-sheet fluorescence microscopy is an excellent tool for the investigation of large three dimensional microscopy samples at the cellular level, however, the ability to resolve features is strongly affected by the presence of scattering and aberrations. These effects are two fold in light-sheet microscopy, as the illumination path...conference paper 2018
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Gupta, Abhimanyu (author)The use of radial basis function (RBF) expansion as a means to represent the generalized pupil function for aberration retrieval from intensity point-spread function has been investigated in this research article. The optimal choice of RBF hyper-parameters is derived empirically to achieve an increased accuracy of approximation along with well...master thesis 2017
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Varnai, Peter (author)We study the important mathematical problem of approximating the inverse of low Kronecker-rank matrices in this same form. A traditional alternating least squares (ALS) scheme for solving such problems is presented, and we discuss two efficient solutions to the subproblems arising in the corresponding iterations. The first relies on a least...master thesis 2017
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Çağlayan, Fatihhan (author)Recently, with the switch to the new generation adaptive optics systems like the VLT and ELT an important identification problem emerged. These telescopes are so-called integrated systems, which means that open-loop calibration of the interaction matrix is not possible anymore. The first and foremost reason for this is that the new generation of...master thesis 2017
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Monchen, G. (author)Adaptive Optics (AO) play an essential role in the field of astronomical seeing for ground-based telescopes, providing a corrected image from the disturbance caused by the light having to travel through the turbulent atmosphere of our Earth. To provide us with more detailed images, the sizes of these telescopes are getting increasingly larger....master thesis 2017
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Verstraete, H.R.G.W. (author)Optical coherence tomography (OCT) is a technique for non-invasive imaging based on low coherence interferometry. Its main application is found in ophthalmology, where it is used for 3D in vivo imaging of the cornea and the retina. OCT has evolved over the past decade as one of the most important ancillary tests in ophthalmic practice, providing...doctoral thesis 2017
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Mocci, J. (author), Cua, M. (author), Lee, S. (author), Jian, Y (author), Pozzi, P. (author), Quintavalla, M. (author), Trestino, C. (author), Verstraete, H.R.G.W. (author), Wahl, D. (author), Muradore, R. (author), Zawadzki, R.J. (author), Verhaegen, M.H.G. (author), Sarunic, M.V. (author), Bonora, S. (author)The use of adaptive lenses instead of deformable mirrors can simplify the implementation of an adaptive optics system. The recently introduced Multi-actuator Adaptive Lens (MAL) can be used in closed loop with a wavefront sensor to correct for time-variant wavefront aberrations. The MAL can guarantee a level of correction and a response time...conference paper 2017
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Bucsa, R.E. (author)In the DCSC group of Prof. Michel Verhaegen a new type of fluorescence microscope has been developed that relies on adaptive optics to correct for aberrations using optimisation of an image metric. The aim of this thesis is to realise a complete simulation of the optical system, and to test a variety of optimisation algorithms in simulation,...master thesis 2016
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Li, X. (author), Wei, L. (author), Poelma, René H. (author), Vollebregt, S. (author), Wei, J. (author), Urbach, Paul (author), Sarro, Pasqualina M (author), Zhang, Kouchi (author)This paper presents a tuneable binary amplitude Fresnel lens produced by wafer-level microfabrication. The Fresnel lens is fabricated by encapsulating lithographically defined vertically aligned carbon nanotube (CNT) bundles inside a polydimethyl-siloxane (PDMS) layer. The composite lens material combines the excellent optical absorption...journal article 2016
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Gong, H. (author), Pozzi, P. (author), Soloviev, O.A. (author), Verhaegen, M.H.G. (author), Vdovin, Gleb (author)We present a reference-less and time-multiplexing phase retrieval method by making use of the digital micromirror device (DMD). In this method, the DMD functions not only as a flexible binary mask which modulates the optical field, but also as a sampling mask for measuring corresponding phases, which makes the whole setup simple and robust. The...conference paper 2016
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Yoo, H.W. (author), van Royen, M.E. (author), van Cappellen, WA (author), Houtsmuller, AB (author), Verhaegen, M.H.G. (author), Schitter, G (author)The pinhole plays an important role in confocal laser scanning microscopy (CLSM) for adaptive optics (AO) as well as in imaging, where the size of the pinhole denotes a trade-off between out-of-focus rejection and wavefront distortion. This contribution proposes an AO system for a commercial CLSM with an adjustable square pinhole to cope with...conference paper 2016
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Verstraete, H.R.G.W. (author), Almasian, M. (author), Pozzi, P. (author), Bilderbeek, R (author), Kalkman, J. (author), Faber, DJ (author), Verhaegen, M.H.G. (author)In this manuscript, we present a lens setup for large defocus and astigmatism correction. A deformable defocus lens and two rotational cylindrical lenses are used to control the defocus and astigmatism. The setup is calibrated using a simple model that allows the calculation of the lens inputs so that a desired defocus and astigmatism are...conference paper 2016
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Wilding, D. (author), Pozzi, P. (author), Soloviev, O.A. (author), Vdovin, Gleb (author), Verhaegen, M.H.G. (author)Aberrations, scattering and absorption degrade the performance light-sheet fluorescence microscopes (LSFM). An adaptive optics system to correct for these artefacts and to optimize the light-sheet illumination is presented. This system allows a higher axial resolution to be recovered over the field-of-view of the detection objective. It is...conference paper 2016