Searched for: author%3A%22Korkiakoski%2C+V.%22
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Korkiakoski, V. (author), Keller, C.U. (author), Doelman, N.J. (author), Kenworthy, M. (author), Otten, G. (author), Verhaegen, M. (author)
We investigate methods to calibrate the non-common path aberrations at an adaptive optics system having a wavefront-correcting device working with an extremely high resolution (larger than 150x150 correcting elements). We use focal-plane images collected successively, the corresponding phase-diversity information and numerically efficient...
conference paper 2014
document
Korkiakoski, V. (author), Keller, C.U. (author), Doelman, N.J. (author), Kenworthy, M. (author), Otten, G.W. (author), Verhaegen, M. (author)
We present two complementary algorithms suitable for using focal-plane measurements to control a wavefront corrector with an extremely high-spatial resolution. The algorithms use linear approximations to iteratively minimize the aberrations seen by the focal-plane camera. The first algorithm, Fast & Furious (FF), uses a weak-aberration...
article 2014
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Korkiakoski, V. (author), Doelman, N.J. (author), Codona, J. (author), Kenworthy, M. (author), Otten, G. (author), Keller, C.U. (author)
We present a method to calibrate a high-resolution wavefront (WF)-correcting device with a single, static camera, located in the focal-plane; no moving of any component is needed. The method is based on a localized diversity and differential optical transfer functions to compute both the phase and amplitude in the pupil plane located upstream of...
article 2013
document
Korkiakoski, V. (author), Keller, C.U. (author), Doelman, N.J. (author), Codona, J. (author), Kenworthy, M. (author)
We show how differential optical transfer function (dOTF) method is used to calibrate an adaptive optics setup using a spatial light modulator. SLM response, rotation and registration are measured sufficiently accurately for high-order WF correction. © OSA 2013.
conference paper 2013
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Smith, C.S. (author), Marinic«é, R. (author), den Dekker, A.J. (author), Verhaegen, M. (author), Korkiakoski, V. (author), Keller, C.U. (author), Doelman, N.J. (author)
We propose an efficient approximation to the nonlinear phase diversity (PD) method for wavefront reconstruction and correction from intensity measurements with potential of being used in real-time applications. The new iterative linear phase diversity (ILPD) method assumes that the residual phase aberration is small and makes use of a first...
article 2013
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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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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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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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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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