Tip-tilt restoration of a segmented optical mirror using a geometric sensor

Fernández-Valdivia, J. J.; Lastra, Alberto; Chueca, S.; Sanz, Javier; Rodríguez-Ramos, José Manuel

doi:10.1117/1.oe.52.5.056601

Cited by 12 publications

(8 citation statements)

References 7 publications

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“…The method proposed in [9] estimates a wave front phase from two symmetrically defocused images. In this method, the phase resolution is only limited by the sensor resolution, besides it has been demonstrated that real-time implementations of the method are possible [10].…”

Section: Relation Of Light Field and Focal Stackmentioning

confidence: 98%

Lightfield super-resolution through turbulence

et al. 2015

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In this paper, we use information from the light field to obtain a distribution map of the wavefront phase. This distribution is associated with changes in refractive index which are relevant in the propagation of light through a heterogeneous or turbulent medium.Through the measurement of the wavefront phase from a single shot, it is possible to make the deconvolution of blurred images affected by the turbulence. If this deconvolution is applied to light fields obtained by plenoptic acquisition, the original optical resolution associated to the objective lens is restored, it means we are using a kind of superresolution technique that works properly even in the presence of turbulence.The wavefront phase can also be estimated from the defocused images associated to the light field: we present here preliminary results using this approach.

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Section: Relation Of Light Field and Focal Stackmentioning

confidence: 98%

Lightfield super-resolution through turbulence

et al. 2015

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“…The experimental setup is identical to that of the nlCWFS but simpler, as it considers only intensity measurements at two planes symmetrically placed at both sides of the aperture. Geometrical optics propagation of the photons is considered, so that the technique is applicable to extended and polychromatic sources [10].…”

Section: Aolimentioning

confidence: 99%

An atmospheric turbulence and telescope simulator for the development of AOLI

et al. 2014

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AOLI, Adaptive Optics Lucky Imager, is the next generation of extremely high resolution instruments in the optical range, combining the two more promising techniques: Adaptive optics and lucky imaging. The possibility of reaching fainter objects at maximum resolution implies a better use of weak energy on each lucky image. AOLI aims to achieve this by using an adaptive optics system to reduce the dispersion that seeing causes on the spot and therefore increasing the number of optimal images to accumulate, maximizing the efficiency of the lucky imaging technique.The complexity of developments in hardware, control and software for in-site telescope tests claim for a system to simulate the telescope performance. This paper outlines the requirements and a concept/preliminary design for the William Herschel Telescope (WHT) and atmospheric turbulence simulator. The design consists of pupil resemble, a variable intensity point source, phase plates and a focal plane mask to assist in the alignment, diagnostics and calibration of AOLI wavefront sensor, AO loop and science detectors, as well as enabling stand-alone test operation of AOLI.

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“…In the ELTs, the number of microlenses and edges grows enormously and, the difficulty of precise alignment requires the search for simpler solutions. The geometric sensor corresponds to a much simpler optical design; in one hand it has been recently demonstrated that it is capable of measuring tip-tilt in every segment with high sensitivity (Fernández-Valdivia et al [2]), and in the other hand it is well known that the geometric sensor is sensitive to the local piston between segments (Rodríguez-Ramos et al [3]). Then co-phasing of the surface can be carried out using only the geometric sensor.…”

Section: Introductionmentioning

confidence: 98%

Co-phasing segmented surfaces using the geometric sensor

Fernández-Valdivia

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Rosa

et al. 2013

2013 12th Workshop on Information Optics (WIO)

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This paper presents a method to co-phase segmented mirror. For this purpose, we use the geometric sensor, thus only two defocused images are acquired. The van Dam and Lane algorithm [1] is applied to obtain the tip-tilt in every segment, and a new method is used to restore the original local piston. Furthermore, by using specialized hardware the computations can be performed in real time, within the stability time of the atmosphere.

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Tip-tilt restoration of a segmented optical mirror using a geometric sensor

Cited by 12 publications

References 7 publications

Lightfield super-resolution through turbulence

Lightfield super-resolution through turbulence

An atmospheric turbulence and telescope simulator for the development of AOLI

Co-phasing segmented surfaces using the geometric sensor

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