Conversion from phase map to coordinate: Comparison among spatial carrier, Fourier transform, and phase shifting methods

Hu, Qingying; Harding, Kevin G.

doi:10.1016/j.optlaseng.2006.01.010

Cited by 15 publications

(5 citation statements)

References 35 publications

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“…Hence we need to compensate for that deviation by introducing a corrective phase pattern on the SLM. To derive the spatial coordinates of a surface from the phase patterns of interferometric measurements using that same surface is a well know problem [104]. A common, multi-image solution is to use a modification of the original Le Carré algorithm [105], the so called phase-shifting interferometry (PSI) [106].…”

Section: Correction For the Backplane Non-flatnessmentioning

confidence: 99%

Optical techniques for Rydberg physics in lattice geometries

Naber

Vos

Rengelink

et al. 2016

Eur. Phys. J. Spec. Top.

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We address the technical challenges when performing quantum information experiments with ultracold Rydberg atoms in lattice geometries. We discuss the following key aspects: (i) The coherent manipulation of atomic ground states, (ii) the coherent excitation of Rydberg states, and (iii) spatial addressing of individual lattice sites. We briefly review methods and solutions which have been successfully implemented, and give examples based on our experimental apparatus. This includes an optical phase-locked loop, an intensity and frequency stabilization setup for lasers, and a nematic liquid-crystal spatial light modulator. a

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Section: Correction For the Backplane Non-flatnessmentioning

confidence: 99%

Optical techniques for Rydberg physics in lattice geometries

Naber

Vos

Rengelink

et al. 2016

Eur. Phys. J. Spec. Top.

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“…[10][11] In phase shift analysis, the pattern is shifted by some fraction of the pattern period, and a series of 3 or more images is taken to generate a phase map of the pattern over the field. [17][18][19] Although it is not required, the pattern is typically assumed to be a sine wave in nature, which makes the calculation of phase more accurate with a minimum number of images. However, projecting a Ronchi ruling actually produces something closer to a square wave pattern, with small errors in the spacing between the lines.…”

Section: Physical Grating Projectorsmentioning

confidence: 99%

“…This type of pattern creates errors in phase calculaitons. [10][11][12][13][14][15][16][17][18][19][20][21] The images are analyzed using methods that allow a determination of the relative phase of any one point by means of analyzing the ratio of the intensities at that one point. The phase at each point is given by:…”

Section: Physical Grating Projectorsmentioning

confidence: 99%

Comparison of projection means for structured light systems

Harding

2009

SPIE Proceedings

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Structured light systems have used many forms of means to create structured patterns ranging from laser lines and physical gratings to current programmable projectors. There are both good and bad aspects of each method, including considerations of contrast, brightness, coherent noise, line stability, and noise associated with the shape of the pattern of lines created. This paper will compare the major means of structured light projection including laser lines, white light gratings, LCDs, DMDs, and LCOS projectors. These method will be analyze with respect to the key performance parameters of the projection means as applied to the most popular means of analysis, including both line center and phase shift analysis. Finally, the results of efforts to characterize the effects of drift of the patterns will be detailed within the context of efforts to obtain absolute distance information at the few micron level.

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“…Fringe projection profilometry (FPP) [1] is commonly used for full-field non-contact surface-shape measurement for a wide range of applications. Phase-shifting profilometry (PSP) [2] has been commonly used because of its high accuracy, high spatial resolution, and low sensitivity to variations of background intensity and surface reflectivity [2,3].…”

Section: Introductionmentioning

confidence: 99%

Multi-Wavelength Digital-Phase-Shifting Moiré Based on Moiré Wavelength

Mohammadi

Kofman

2019

Applied Sciences

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Multi-wavelength digital-phase-shifting moiré was demonstrated using multiple moiré wavelengths determined by system calibration over the full working depth. The method uses the extended noisy phase map as a reference to unwrap the phase map with a shorter wavelength, and thus achieve a less noisy and more accurate continuous phase map. The moiré wavelength calibration determines a moiré-wavelength to height relationship that permits pixelwise refinement of the moiré wavelength and height during 3D reconstruction. Only a single pattern has to be projected and, thus, a single image captured to compute each phase map with a different wavelength to perform digital-phase-shifting moiré temporal phase unwrapping. Only two captured images are required for two-wavelength phase unwrapping and three captured images for three-wavelength phase unwrapping. The method has been demonstrated in the 3D surface-shape measurement of an object with surface discontinuities and spatially isolated objects.

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Conversion from phase map to coordinate: Comparison among spatial carrier, Fourier transform, and phase shifting methods

Cited by 15 publications

References 35 publications

Optical techniques for Rydberg physics in lattice geometries

Optical techniques for Rydberg physics in lattice geometries

Comparison of projection means for structured light systems

Multi-Wavelength Digital-Phase-Shifting Moiré Based on Moiré Wavelength

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