Multiple-wavelength phase-shifting interferometry

We present a single shot low coherence white light Hilbert phase microscopy (WL-HPM) for quantitative phase imaging of Si opto-electronic devices, i.e., Si integrated circuits (Si-ICs) and Si solar cells. White light interferograms were recorded by a color CCD camera and the interferogram is decomposed into the three colors red, green and blue. Spatial carrier frequency of the WL interferogram was increased sufficiently by means of introducing a tilt in the interferometer. Hilbert transform fringe analysis was used to reconstruct the phase map for red, green and blue colors from the single interferogram. 3D step height map of Si-ICs and Si solar cells was reconstructed at multiple wavelengths from a single interferogram. Experimental results were compared with Atomic Force Microscopy and they were found to be close to each other. The present technique is non-contact, full-field and fast for the determination of surface roughness variation and morphological features of the objects at multiple wavelengths.

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“…to avoid phase ambiguity [32,[46][47][48]. Figure 9(a) shows the height map for synthetic wavelength RG Λ and Fig.…”

Section: Results and Analysismentioning

confidence: 99%

Single Shot White Light Interference Microscopy for 3D Surface Profilometry Using Single Chip Color Camera

Srivastava

Inam²,

Kumar³

et al. 2016

Journal of the Optical Society of Korea

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“…To obtain quantitative phase images, one can perform an interferometric measurement of a focused beam of light on an object, and scan the beam over the object in a raster fashion. Optical profilers based on scanning interferometers are especially well suited for imaging applications in materials science, as in MEMS and nanofabrication, because of the high precision obtainable and the static nature of the objects being imaged [39,40]. On the other hand, the speed constraint and mechanical complexity of scanning interferometers can significantly restrict the range of applications in biomedical imaging [41], where one needs to make observations of dynamic processes under widely varying environments.…”

Section: Quantitative Phase Microscopymentioning

confidence: 99%

Principles and techniques of digital holographic microscopy

2010

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Abstract. Digital holography is an emerging field of new paradigm in general imaging applications. We present a review of a subset of the research and development activities in digital holography, with emphasis on microscopy techniques and applications. First, the basic results from the general theory of holography, based on the scalar diffraction theory, are summarized, and a general description of the digital holographic microscopy process is given, including quantitative phase microscopy. Several numerical diffraction methods are described and compared, and a number of representative configurations used in digital holography are described, including off-axis Fresnel, Fourier, image plane, in-line, Gabor, and phase-shifting digital holographies. Then we survey numerical techniques that give rise to unique capabilities of digital holography, including suppression of dc and twin image terms, pixel resolution control, optical phase unwrapping, aberration compensation, and others. A survey is also given of representative application areas, including biomedical microscopy, particle field holography, micrometrology, and holographic tomography, as well as some of the special techniques, such as holography of total internal reflection, optical scanning holography, digital interference holography, and heterodyne holography. The review is intended for students and new researchers interested in developing new techniques and exploring new applications of digital holography. C 2010 Society of Photo-Optical Instrumentation Engineers.

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“…To avoid the problems caused by a conventional spatial phase unwrapping algorithm, multiple-wavelength phase-shifting algorithms have been proposed. [18][19][20][21][22] For these techniques, the minimum number of three frequencies are required, 22 where at least 9 fringe images have to be used. Multiple-wavelength methods certainly will reduce the measurement speed because more fringe images are required.…”

Section: Digital Multiple-wavelength Phase-shifting Algorithmmentioning

confidence: 99%

Optimal checkerboard selection for structured light system calibration

Lohry

Zhang

2009

SPIE Proceedings

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Structured light system calibration has been widely studied over the decades, and a variety of calibration approaches have been proposed. Among these methods, the flexible method using flat checkerboard is widely adopted. However, there is a lack of studies on selecting the optimal checker size for high accuracy calibration, whilst it is vital to understanding this factor. This paper presents a systematic study on how the checker size affects the calibration accuracy for a structured light system, and provides a general guideline to select the optimal size. For this initial study, 7 different checker sizes are selected, and experiments demonstrated that the system achieved the best calibration accuracy within a certain range of checker size. ABSTRACTStructured light system calibration has been widely studied over the decades, and a variety of calibration approaches have been proposed. Among these methods, the flexible method using flat checkerboard is widely adopted. However, there is a lack of studies on selecting the optimal checker size for high accuracy calibration, whilst it is vital to understanding this factor. This paper presents a systematic study on how the checker size affects the calibration accuracy for a structured light system, and provides a general guideline to select the optimal size. For this initial study, 7 different checker sizes are selected, and experiments demonstrated that the system achieved the best calibration accuracy within a certain range of checker size.

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Multiple-wavelength phase-shifting interferometry

Cited by 288 publications

References 4 publications

Single Shot White Light Interference Microscopy for 3D Surface Profilometry Using Single Chip Color Camera

Single Shot White Light Interference Microscopy for 3D Surface Profilometry Using Single Chip Color Camera

Principles and techniques of digital holographic microscopy

Optimal checkerboard selection for structured light system calibration

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