A simple low-order adaptive optics system for near-infrared applications

Roddier, F.; Northcott, M. J.; Graves, J. E.

doi:10.1086/132802

Cited by 160 publications

(67 citation statements)

References 11 publications

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“…This allows the PS sensitivity to be adjusted in order to deal with different amplitudes of the incoming wavefront aberration. In closed loop operation, the sensitivity can be increased as the wavefront correction progresses, as is usually done in the case of curvature sensing systems Roddier et al 1991). In the case of a circular tip-tilt modulation having amplitude bigger than the local tilt of the aberrated wavefront w(x, y), geometrical optics calculations show that (Esposito et al 1999;Riccardi et al 1998):…”

Section: Ps Principle Of Operationmentioning

confidence: 99%

Pyramid Wavefront Sensor behavior in partial correction Adaptive Optic systems

Esposito

Riccardi

2001

A&A

111

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Abstract. In this letter we evaluate the limiting magnitude for a Pyramid Sensor operating in a closed loop astronomical Adaptive Optics system. A first heuristic analysis has shown that, when a point-like reference source is used a pyramid sensor exhibits a significant gain in terms of limiting magnitude over the widely used ShackHartmann sensor. This when diffraction limited conditions are reached. However, in current astronomical Adaptive Optics, diffraction limited regime at the sensing wavelength is difficult to achieve. Our simulations quantify the pyramid sensor limiting magnitude considering an Adaptive Optics system working in a partial correction regime. The simulations show that the considered gain is retained even in partial correction. An average gain of two magnitude is found in the considered case. This feature of a pyramid sensor can be very important in reducing the fundamental limit of today's Astronomical Adaptive Optics systems using natural reference sources, i.e. the limited sky-coverage.

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Section: Ps Principle Of Operationmentioning

confidence: 99%

Pyramid Wavefront Sensor behavior in partial correction Adaptive Optic systems

Esposito

Riccardi

2001

A&A

111

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“…Unlike conventional AO systems developed for defense application, the UH AO system is based on the concept of wavefront curvature sensing and compensation (Roddier 1988) and was specifically developed at the Institute for Astronomy (IfA) for astronomical observations (Roddier et al 1991). A small (30-mmdiameter) image of the telescope entrance aperture is formed on a 13-actuator deformable mirror which compensates for wavefront aberrations.…”

Section: Observationsmentioning

confidence: 99%

Adaptive Optics Observations of Saturn's Ring Plane Crossing in August 1995

Roddier

Brahic

et al. 2000

Icarus

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“…Brighter cores result in detection of dimmer stars, particularly important in light polluted sites. Calculations (9) show that the Strehl ratio improvement, due to 5 mode correction, for all Dir0 ratios between 3 and 10 results in detection of stars two stellar magnitudes dimmer than an uncorrected telescope. For r0 between 10 cm and 20 cm, this covers all telescopes between 0.3 and 2 meters.…”

Section: Theoretical Performancementioning

confidence: 96%

“…Removing the next four types of coma (a total of 9 corrections) only improves this to D =6.3 * r0. Roddier et al (9) have studied this effect in detail, and one of their performance graphs is shown in Figure 1 on the next page. Clearly, higher order systems face increasing costs with diminishing returns.…”

Section: Theoretical Performancementioning

confidence: 99%

<title>Five-order correction adaptive optics system for meter-class telescopes</title>

Meyer

1994

Adaptive Optics in Astronomy

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An adaptive optics system for small to medium astronomical telescopes has been designed and is under construction. This adaptive optics system corrects the five lowest order Zernike wavefront aberrations, providing near diffiaction-limited performance for telescope diameters smaller than about 5*r0, and useful correction up to about 10*r0. This adaptive optics system design consists of a lens-based wavefront aberrator, a CCD-based Shack-Hartmann wavefront sensor, and a personal computer-based feedback loop.The wavefront aberrator uses a series ofvoice-coil translated thin lenses in a collimated beam to compensate tip, tilt, defocus, xy-astigmatism, and x2-y2-astigmatism. Translating weak lenses perpendicular to the optical axis applies the tip and tilt corrections. Defocus and astigmatism are applied by translating along the optical axis, one lens of a nearly zero-power lens pair. Voice coil actuators reduce cost and permit relatively large lens translations.The wavefront sensor uses a single lens to focus four subapertures. Weak beamsteering prisms align the images near the readout edge of a small CCD. Personal computer software rapidly converts the quad sensor signals to the voltages for the wavefront aberrator voice coils.Internal optics include an alignment pinhole to aid realignment. Calibration, including determining the measurement matrix and the reconstructor, will be automated.

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A simple low-order adaptive optics system for near-infrared applications

Cited by 160 publications

References 11 publications

Pyramid Wavefront Sensor behavior in partial correction Adaptive Optic systems

Pyramid Wavefront Sensor behavior in partial correction Adaptive Optic systems

Adaptive Optics Observations of Saturn's Ring Plane Crossing in August 1995

<title>Five-order correction adaptive optics system for meter-class telescopes</title>

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