Searched for: subject%3A%22OM%255C%2B%255C-%255C%2BOpto%255C-Mechatronics%22
(101 - 120 of 144)
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de Boer, B.M. (author), Durkut, M. (author), Laan, E. (author), Hakkesteegt, H. (author), Theuwissen, A. (author), Xie, N. (author), Leijtens, J.L. (author), Urquijo, E. (author), Bruins, P. (author)A high-precision and low-power miniaturized digital sun sensor has been developed at TNO. The single-chip sun sensor comprises an application specific integrated circuit (ASIC) on which an active pixel sensor (APS), read-out and processing circuitry as well as communication circuitry are combined. The design was optimized for low recurrent cost....conference paper 2012
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Andrei, R.M. (author), Fraanje, P.R. (author), Verhaegen, M. (author), Korkiakoski, V.A. (author), Keller, C.U. (author), Doelman, N.J. (author)We propose a new approach for the joint estimation of aberration parameters and unknown object from diversity images with applications in imaging systems with extended objects as astronomical ground-based observations or solar telescopes. The motivation behind our idea is to decrease the computational complexity of the conventional phase...conference paper 2012
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Korkiakoski, V. (author), Keller, C.U. (author), Doelman, N.J. (author), Fraanje, P.R. (author), Andrei, R. (author), Verhaegen, M. (author)We show experimental results demonstrating the feasibility of an extremely fast sequential phase-diversity (SPD) algorithm for point sources. The algorithm can be implemented on a typical adaptive optics (AO) system to improve the wavefront reconstruction beyond the capabilities of a wavefront sensor by using the information from the imaging...conference paper 2012
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Pijnenburg, J.A.C.M. (author), te Voert, M.J.A. (author), de Vreugd, J. (author), Vosteen, L.L.A. (author), van Werkhoven, W.P. (author), Mekking, J. (author), Nijland, B.A.H. (author)Through the years many stable optical mounts have been designed, analyzed and tested at TNO. This paper gives an overview of the design principles used. Various examples are presented together with verification test results. The use of adhesives in combination with an iso-static mount design allows mounting of optical components in a limited...conference paper 2012
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Nijenhuis, J.R (author), Hamelinck, R.F.M.M. (author), Braam, B.C. (author)The mirror segments for the E-ELT and TLT are nearly equal in size and shape (hexagonal, 1.2 m over flat sides). They are very thin (about 50 mm) compared to their size. Supporting these mirrors and obtaining high optical performance is a challenge from design and manufacturing point of view. TNO has designed and build (together with VDL-ETG)...conference paper 2012
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Korkiakoski, V. (author), Venema, L. (author), Agocs, T. (author), Keller, C.U. (author), Doelman, N.J. (author), Fraanje, P.R. (author), Andrei, R. (author), Verhaegen, M. (author)We investigate the potential of phase-diversity (PD) and Gerchberg-Saxton (GS) algorithms in the calibration of active instruments. A set of images is recorded with the focal-plane scientific camera, each image having a known and unique defocus. The phase-retrieval algorithms are used, with those images, to estimate the non-common path...conference paper 2012
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Korkiakoski, V. (author), Keller, C.U. (author), Doelman, N.J. (author), Fraanje, P.R. (author), Verhaegen, M. (author)We study different possibilities to use adaptive optics (AO) and phase diversity (PD) together in a jointly optimized system. The potential of the joint system is demonstrated through numerical simulations. We find that the most significant benefits are obtained from the improved deconvolution of AO-corrected wavefronts and the additional...article 2012
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Bouma, H. (author), van der Mark, W. (author), Eendebak, P.T. (author), Landsmeer, S. (author), van der Eekeren, A.W.M. (author), ter Haar, F.B. (author), Wieringa, F.P. (author), van Basten, J.P. (author)Compared to open surgery, minimal invasive surgery offers reduced trauma and faster recovery. However, lack of direct view limits space perception. Stereo-endoscopy improves depth perception, but is still restricted to the direct endoscopic field-of-view. We describe a novel technology that reconstructs 3D-panoramas from endoscopic video streams...conference paper 2012
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Jellema, W. (author), Kruizinga, B. (author), Visser, H. (author), van den Dool, T.C. (author), Santos, C.P. (author), Redondo, J.T. (author), Eggens, M. (author), Ferlet, M. (author), Swinyard, B. (author), Dohlen, K. (author), Griffin, D. (author), Fernandez, L.M.G. (author), Belenguer, T. (author), Matsuhara, H. (author), Kawada, M. (author), Doi, Y. (author)The Safari instrument on the Japanese SPICA mission is a zodiacal background limited imaging spectrometer offering a photometric imaging (R ≈ 2), and a low (R = 100) and medium spectral resolution (R = 2000 at 100 μm) spectroscopy mode in three photometric bands covering the 34-210 μm wavelength range. The instrument utilizes Nyquist sampled...conference paper 2012
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Henselmans, R. (author), Nijkerk, M.D. (author), Lemmen, M.H.J. (author), Rijnveld, N. (author), Kamphues, F.G. (author)TNO has developed the Optical Tube Assemblies (OTAs) for the ESO VLT Four Laser Guide Star Facility. The OTAs are Galilean 20x beam expanders, expanding a ∅15 mm input beam (25W, 589 nm CW) to a steerable ∅300 mm output beam. TNO has recently successfully completed acceptance testing of the four units, showing compliance to the challenging...conference paper 2012
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Andrei, R.M. (author), Smith, C.S. (author), Fraanje, P.R. (author), Verhaegen, M. (author), Korkiakoski, V.A. (author), Keller, C.U. (author), Doelman, N.J. (author)In this paper we give a new wavefront estimation technique that overcomes the main disadvantages of the phase diversity (PD) algorithms, namely the large computational complexity and the fact that the solutions can get stuck in a local minima. Our approach gives a good starting point for an iterative algorithm based on solving a linear system,...conference paper 2012
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Keller, C.U. (author), Korkiakoski, V. (author), Doelman, N.J. (author), Fraanje, P.R. (author), Andrei, R. (author), Verhaegen, M. (author)We present a promising approach to the extremely fast sensing and correction of small wavefront errors in adaptive optics systems. As our algorithm's computational complexity is roughly proportional to the number of actuators, it is particularly suitable to systems with 10,000 to 100,000 actuators. Our approach is based on sequential phase...conference paper 2012
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Verlaan, A.L. (author), Hogenhuis, H. (author), Pijnenburg, J.A.C.M. (author), Lemmen, M.H.J. (author), Lucarelli, S. (author), Scheulen, D. (author), Ende, D. (author)The LISA Optical Stability Characterization project is part of the LISA CTP activities to achieve the required Technonlogy Readiness Level (TRL) for all of the LISA technologies used. This activity aims demonstration of the Telescope Assembly (TA), with a structure based on CFRP technology, that a CTE of 10 -7 1/K can be achieved with measures...conference paper 2012
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Pijnenburg, J.A.C.M. (author), Rijnveld, N. (author), Hogenhuis, H. (author)Detection and observation of gravitational waves requires extreme stability in the frequency range 3e-5 Hz to 1 Hz. NGO/LISA will attain this by creating a giant interferometer in space, based on free floating proof masses in three spacecrafts. To operate NGO/LISA, the following piezo mechanisms are developed: 1. A piezo stack mechanism (Point...conference paper 2012
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de Vreugd, J. (author), te Voert, M.J.A. (author), Nijenhuis, J.R. (author), Pijnenburg, J.A.C.M. (author), Tabak, E. (author)Adhesives are widely used in optomechanical structures for bonding optical components to their mounts. The main advantage of using adhesives is the excellent strength to weight ratio. Adhesive bonding is seen as a desirable joining technique as it allows for greater flexibility in design. A disadvantage of adhesives however is the limited...conference paper 2012
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Pijnenburg, J.A.C.M. (author), te Voert, M.J.A. (author), de Vreugd, J. (author), Vosteen, L.L.A. (author), van Werkhoven, W.P. (author), Mekking, J. (author), Nijland, B.A.H. (author)Through the years many stable optical mounts have been designed, analyzed and tested at TNO. This paper gives an overview of the design principles used. Various examples are presented together with verification test results. The use of adhesives in combination with an iso-static mount design allows mounting of optical components in a limited...public lecture 2012
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Kasparek, W. (author), van den Braber, R. (author), Doelman, N.J. (author), Fritz, E. (author), Erckmann, V. (author), Hollmann, F. (author), Michel, G. (author), Noke, F. (author), Purps, F. (author), Bongers, W. (author), Krijger, B. (author), Petelin, M. (author), Lubyako, L. (author), Bruschi, A. (author)Electron cyclotron resonance heating (ECRH) systems for next-step large fusion devices operate in continuous wave power in the multimegawatt range. The unique feature of narrow and well-localized power deposition assigns a key role to ECRHfor different tasks, such as plasma start-up, electron heating, current drive, magnetohydrodynamic (MHD)...article 2011
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Korkiakoski, V. (author), Keller, C. (author), Doelman, N.J. (author), Fraanje, P.R. (author), Verhaegen, M. (author)We demonstrate the potential of joint-optimization of adaptive optics (AO) and phase-diversity (PD). The wavefront sensor information reduces computational costs by a factor of 20, and PD can reconstruct much better the AO corrected images.conference paper 2011
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Doelman, N.J. (author), Fraanje, P.R. (author), den Breeje, R. (author)An H2-optimal control approach for Adaptive Optics has been validated in an on-sky experiment on a solar telescope. A substantial performance improvement over the integrator control approach is demonstrated for control of the tip-tilt modes. The experimental results correspond reasonably well with simulations based on measured data.conference paper 2011
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Henselmans, R. (author), Cacace, L.A. (author), Kramer, G.F.Y. (author), Rosielle, P.C.J.N. (author), Steinbuch, M. (author)Aspherical and freeform optics are applied to reduce geometrical aberrations as well as to reduce the required number of components, the size and the weight of the system. To measure these optical components with nanometre level uncertainty is a challenge. The NANOMEFOS machine was developed to provide suitable metrology (high accuracy,...article 2011
Searched for: subject%3A%22OM%255C%2B%255C-%255C%2BOpto%255C-Mechatronics%22
(101 - 120 of 144)