Journal ArticleDOI
Wave-front reconstruction for compensated imaging
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TLDR
In this paper, the authors analyzed the conversion from phase differences to phases and derived the optimal linear estimator in terms of least noise propagation for a compensated imaging (CI) system.Abstract:
A critical component in a compensated imaging (CI) system is the wave-front sensor which measures the residual distortion of the wave front after reflecting off the active mirror. The sensor produces estimates of wave-front slopes or phase difference across the aperture. For many applications, the phase differences or slopes are not the most convenient form of data for processing or control, and they must be converted to absolute wave-front phases. This paper analyzes the conversion from phase differences to phases and derives the optimal linear estimator in terms of least noise propagation. Some remarks concerning hardware implementation are also made.read more
Citations
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A novel phase unwrapping method based on network programming
TL;DR: A new phase unwrapping method is described and tested, which starts from the fact that the phase differences of neighboring pixels can be estimated with a potential error that is an integer multiple of 2/spl pi/.
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Robust two-dimensional weighted and unweighted phase unwrapping that uses fast transforms and iterative methods
TL;DR: In this article, a robust method for 2D phase principal values (in a least-squares sense) by using fast cosine transforms was developed, which can be used to isolate inconsistent regions (i.e., phase shear).
Journal ArticleDOI
Wave-front estimation from wave-front slope measurements
TL;DR: In this paper, the problem of wavefront estimation from wave-front slope measurements has been examined from a least-squares curve fitting model point of view, and a new zonal phase gradient model is introduced and its error propagator, which relates the mean square wavefront error to the noisy slope measurements, has been compared with two previously used models.
Journal ArticleDOI
Curvature sensing and compensation: a new concept in adaptive optics.
TL;DR: In this paper, the authors describe a systeme a boucle fermee utilisant un miroir bimorphe for perturbation atmospherique, en temps reel, de fronts d'onde soumis a une perturbations atmosphereherique.
Journal ArticleDOI
Minimum Lp-norm two-dimensional phase unwrapping
TL;DR: In this paper, the minimum Lp-norm solution is obtained by embedding the transform-based methods for unweighted and weighted least squares within a simple iterative structure, and the data-dependent weights are generated within the algorithm and need not be supplied explicitly by the user.
References
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Journal ArticleDOI
Real-time atmospheric compensation
TL;DR: In this paper, an active optical imaging system capable of correcting optical wave-front errors in real time at frequencies in the kilohertz range was developed, which can be applied to apertures of any size; experimental results were shown for a system with 21 correction zones.
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White Light Extended Source Shearing Interferometer
TL;DR: A grating lateral shear interferometer is described that can be used with a white light source and the use of the interferometers with certain types of extended sources is demonstrated.
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Monolithic piezoelectric mirror for wavefront correction
TL;DR: In this paper, the authors show that a spatially varying potential applied to one surface of a thick block of piezoelectric material will induce a deformation of that surface proportional to the potential at each point of the surface.
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Photon noise and atmospheric noise in active optical systems
TL;DR: In this paper, a general theoretical analysis of the performance of optical systems that are designed to give diffraction-limited images of astronomical objects by compensating effects of atmospheric seeing in real time is made.