Dual-technology optical sensor head for 3D surface shape measurements on the micro- and nanoscales

Artigas, Roger; Laguarta, Ferran; Cadevall, Cristina

doi:10.1117/12.545701

Cited by 13 publications

(13 citation statements)

References 6 publications

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“…In vivo corneal measurements are subject to variability in the sample and also to uncertainty in centration and alignment. We also used a microscopy-based non-contact optical profilometer (Pl 2300, Sensofar, Barcelona, Spain) [29] to obtain repeated profilometric measurements of an aspheric intraocular lens (Alcon Acrysoft IQ, power 22 D, nominal R = 20 mm, Q = −33.23) [30]. The instrument was programmed to take 36 two-dimensional (2D) profiles at identical exact conditions (within less than 140 min), using the confocal mode of the instrument, as described in [24].…”

Section: Lens Profilometrymentioning

confidence: 99%

Correlation between radius and asphericity in surfaces fitted by conics

2010

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The optical surfaces of the eye are often described in terms of their radius and asphericity. The variations caused by experimental noise in repeated measurements of radius and asphericity of the same surface are strongly correlated. We show this correlation in experimental corneal elevation data from videokeratoscopy and Scheimpflug topography, in non-contact profilometry data of artificial lenses, and in simulations. The effect is a characteristic of the fits to conic curves, and not restricted to any experimental device or fitting procedure. A separate analysis of radius and asphericity may estimate incorrectly the statistical significance of the changes in the ocular surfaces. We propose a MANOVA-based statistical analysis that increases sensitivity by a factor of 4.

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Section: Lens Profilometrymentioning

confidence: 99%

Correlation between radius and asphericity in surfaces fitted by conics

2010

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“…The inevitable stop-and-go gives rise to an extremely low speed and to mechanical wear. Several solutions introduced in [13,14,15] try to bypass this problem by exploiting the spatial information. These papers describe how the "local" contrast is extracted via the numeric lateral differentiation of the observed pattern.…”

Section: Efficient Depth Scanning Without Stop-and-gomentioning

confidence: 99%

Better three-dimensional inspection with structured illumination: speed

2016

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Three-dimensional (3D) inspection in the factory requires precision and speed. While customers can select from a wide spectrum of high-precision sensors, the real challenge today is "speed." We discuss the speed of 3D sensors in a general context to provide an understanding of why high-resolution 3D sensors deliver significantly fewer 3D points per second than the available camera pixel rates suggest. The major cause of low speed is the large number E of required exposures due to the unavoidable depth scanning. Through the example of structured-illumination microscopy (SIM), we demonstrate how E can be minimized without reducing precision. We further demonstrate a lateral scanning strategy that operates at a significantly higher speed for macroscopic measurements by avoiding explicit depth scanning. This paper is a follow up on an earlier paper about the precision limits of SIM and exploits the earlier results.

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“…A PACM can be arranged in illumination only mode, and in illumination and detection mode (Artigas 2004). In illumination only mode the pixels of the microdisplay are used to restrict the light impinging onto the surface while the optical sectioning is achieved by the use of the pixels of a CCD camera.…”

Section: Programmable Array Scanning Confocal Microscope Configurationmentioning

confidence: 99%

Optical Measurement of Surface Topography

2011

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Dual-technology optical sensor head for 3D surface shape measurements on the micro- and nanoscales

Cited by 13 publications

References 6 publications

Correlation between radius and asphericity in surfaces fitted by conics

Correlation between radius and asphericity in surfaces fitted by conics

Better three-dimensional inspection with structured illumination: speed

Optical Measurement of Surface Topography

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