Pierre Fleury 1894-1976

Maréchal, André

doi:10.1088/0335-7368/7/6/408

Cited by 4 publications

(5 citation statements)

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“…A new expression, which is asymptotically exact for small and large values of Dlr 0 , and which quite accurately represents the Strehl ratios at intermediate values, both for natural and for partially compensated wave fronts, will now be derived. Maréchal (1947) (see also Bom and Wolf 1965) has shown that when the variance cr 2 of an aberrated wave front is small, for any structure function of the aberrations 5(cf 2 <^1) = 1 C7 2 .…”

Section: The Psf Strehl Ratiomentioning

confidence: 99%

The Telescope Point Spread Function

Racine¹

1996

PASP

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New observations are used to accurately define the stellar point-spread function produced by atmospheric turbulence at the focus of large telescopes and to compare its profile to those computed from wave fronts characterized by various structure functions. Excellent agreement is found with the PSF expected from Kolmogorov statistics, except for the presence of an extended aureole of light which appears to result from a combination of instrumental and atmospheric light scattering. Simple yet accurate analytical fits are developed to represent the PSF profile over a range of 15 magnitudes in surface brightness. The relation between the Strehl ratio S of the PSF and the value of the parameter D/r 0 is rediscussed, both for a natural wave front and for a wave front whose variance A* is reduced by an adaptive optics systems. A simple expression for S(D/r 0 ,A#) is proposed and shown to yield essentially correct Strehl ratios for any value of the parameters.

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Section: The Psf Strehl Ratiomentioning

confidence: 99%

The Telescope Point Spread Function

Racine¹

1996

PASP

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“…To analyze the Strehl performance of UnISIS, we use the extended Marechal approximation (Marechal 1947), an approximation that works well with Strehl >0:2. If we designate the Strehl ratio with the symbol S and the total residual wavefront error with K ¼ σ 2 Tot , then following the relationship holds S ∼ e ÀK ;…”

Section: Unisis Ao Performancementioning

confidence: 99%

UnISIS: Laser Guide Star and Natural Guide Star Adaptive Optics System

Thompson

Teare

Xiong

et al. 2009

PUBL ASTRON SOC PAC

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is a versatile adaptive optics system mounted on a large optics bench at the coudé focus of the Mount Wilson 2.5-m telescope. It was designed to have both laser guide star (LGS) and natural guide star (NGS) adaptive optics capabilities. The LGS side of the system relies on a pulsed UV laser with raw power of 30 W capable of creating an artificial laser star via Rayleigh scattering 18 km above the telescope. The LGS system can work at temporal response rates as high as 333 Hz-limited by the UV laser pulse rate-and the NGS system can work at rates up to 1.4 kHz. Each side of the system has its own highspeed wavefront sensor that runs separately, but in the LGS mode the NGS wavefront sensor is converted into a natural star tip-tilt sensor. The deformable mirror is conjugate to the telescope's primary mirror and has one of the most densely packed sets of actuators of any adaptive optics system currently in operation. This paper provides details of the UnISIS design and describes key updates we have made to the system. We show NGS AO-corrected images from the sky from the 900 nm z-band through the 2.12 μm K s band. The highest NGS Strehl achieved to date is 0.67 at K s band.

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“…So no additional forces must be applied which could cause some pressure onto the lens group resulting in a measurement error. The Mirau objective (1) halogen lamp, (2,3,4) lens system to realize a Köhler illumination, (5) aperture stop, (6) field stop, (7) beam splitter, (8) lens with a beam splitter, (10) and a reference mirror (9) added to build the Mirau-objective, (11) annular knife edge, (12) lens under test in in its mounting (13), (14) tube lens to image the fringe pattern on a CCD-chip (15), (16) high accuracy length gauge. The column on the right side shows a series of fringe pattern at different focus positions, in (e) the focus hits the lens vertex.…”

Section: Measuring Of the Lens Vertex Positionmentioning

confidence: 99%

Ultra-high-performance microscope objectives: the state of the art in design, manufacturing, and testing

et al. 2007

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During the last years, new microscope applications require an increased resolution which enforces the development of new state of the art high NA immersion objectives. With the introduction of the 4Pi confocal fluorescence microscope, the increase of the numerical aperture from NA=1.4 to NA=1.46 makes sense, although the gain of lateral resolution is quite small. On the other hand, for inspection and metrology in the semiconductor industry the continuously decreasing structures need the highest possible resolution, which can be achieved with high NA water immersion objectives working in the DUV wavelength range. Building this kind of objectives requires special measuring and testing technologies and a manufacturing precision which has never been realized before in series production.

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Pierre Fleury 1894-1976

Cited by 4 publications

References 0 publications

The Telescope Point Spread Function

The Telescope Point Spread Function

UnISIS: Laser Guide Star and Natural Guide Star Adaptive Optics System

Ultra-high-performance microscope objectives: the state of the art in design, manufacturing, and testing

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