Microscopic TV shearography for characterization of microsystems
TL;DR: A microscopic TV shearographic configuration for characterization of microsystems is demonstrated by measuring the slope under relatively large out-of-plane deformation by combining a long working distance zoom imaging system with a conventional Michelson shear interferometer.
Abstract: We demonstrate a microscopic TV shearographic configuration for characterization of microsystems by measuring the slope under relatively large out-of-plane deformation. In the optical arrangement, a long working distance zoom imaging system is combined with a conventional Michelson shear interferometer. The experimental results on a microelectromechanical system pressure sensor subjected to external pressure load are presented.
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TL;DR: A comprehensive overview of shearography is presented, describing the principle of operation, optical configurations, image processing algorithms and applications, with a focus on more recent technological advances.
Abstract: Shearography is a full-field speckle interferometric technique used to determine surface displacement derivatives. For an interferometric technique, shearography is particularly resilient to environmental disturbances and has hence become an invaluable measurement tool outside of the optics laboratory. Furthermore, the inclusion of additional measurement channels has turned shearography from a qualitative inspection tool into a system suitable for quantitative surface strain measurement. In this review article we present a comprehensive overview of the technique, describing the principle of operation, optical configurations, image processing algorithms and applications, with a focus on more recent technological advances.
213 citations
Cites methods from "Microscopic TV shearography for cha..."
...Kumar et al [124] describe the analysis of a MEMS device...
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...Kumar et al [124] describe the analysis of a MEMS device using a conventional Michelson shearing interferometer....
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TL;DR: This work demonstrates a novel digital shearography system with a large angle of view in the optical arrangement, where the imaging lens is in front of the Michelson interferometer rather than behind it as in traditional digitalShearography.
Abstract: Digital shearography based on Michelson interferometers suffers from the disadvantage of a small angle of view due to the structure. We demonstrate a novel digital shearography system with a large angle of view. In the optical arrangement, the imaging lens is in front of the Michelson interferometer rather than behind it as in traditional digital shearography. Thus, the angle of view is no longer limited by the Michelson interferometer. The images transmitting between the separate lens and camera are accomplished by a 4f system in the new style of shearography. The influences of the 4f system on shearography are also discussed.
37 citations
Cites methods from "Microscopic TV shearography for cha..."
..., Michelson interferometers [8,9], glass wedges [10,11], Fresnel’s biprisms [12], Wollaston prisms [13,14], or glass plates with parallel faces [15], were used to obtain the sheared images....
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TL;DR: The recent advances in multi-colour interferometric techniques and their demanding applications for characterization of micro-systems, non-destructive testing, and bio-imaging applications are reviewed.
26 citations
Cites methods from "Microscopic TV shearography for cha..."
...function microscopic TV holo-shearography systems have been demonstrated for NDT of microsystems [15]....
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...TV holography under microscopic configuration was demonstrated for characterization of shape, deformation, NDT on microsystems such as MEMS (Micro-Electro-Mechanical Systems) [2, 4, 12-15]....
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TL;DR: In this article, an educational tool has been prepared for obtaining short-term and more economic training on digital speckle shearography (DSS) for non-destructive testing in aerospace, electronics and medical device manufacturing.
Abstract: In this study, an educational tool has been prepared for obtaining short-term and more economic training on digital speckle shearography (DSS). Shearography non-destructive testing (NDT) has gained wide acceptance over the last decade, providing a number of important and exciting inspection solutions in aerospace, electronics and medical device manufacturing. For exploring these motivations, it is important to develop didactic tools to understand the potential of digital shearography through training and didactic courses in the field of NDT. In this paper we describe a simple tool for making one familiar with the potential of DSS in the area of education and training. The system is realized with a simple and economic optical setup and a virtual instrument based on the LabVIEW™ and DAQ.
12 citations
TL;DR: In this article, a novel digital shearography set-up with a large angle of view, which is based on the combination of new CCD technology, a semiconductor laser, a Mach-Zehnder shear interferometer and a 4f system, is demonstrated.
12 citations
References
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TL;DR: It is shown that a simple process such as multiple repetition of an anisotropic sine/cosine average filter produces the effect of an excellent automatic adaptive filter for filtering speckle-interferometric phase fringe patterns.
229 citations
TL;DR: This work presents five different eight-point phase-shifting algorithms, each with a different window function, and demonstrates that the shape of the window function significantly influences phase error.
Abstract: We present five different eight-point phase-shifting algorithms, each with a different window function. The window function plays a crucial role in determining the phase (wavefront) because it significantly influences phase error. We begin with a simple eight-point algorithm that uses a rectangular window function. We then present alternative algorithms with triangular and bell-shaped window functions that were derived from a new error-reducing multiple-averaging technique. The algorithms with simple (rectangular and triangular) window functions show a large phase error, whereas the algorithms with bell-shaped window functions are considerably less sensitive to different phase-error sources. We demonstrate that the shape of the window function significantly influences phase error.
117 citations
TL;DR: This poster presents a probabilistic procedure for inferring the shape of the Tv-Holography system using Holographic Microscopy and White-Light Interferometry data.
30 citations
TL;DR: In this article, a microscopic TV holographic system using a long working distance microscope with an extended zoom range has been developed for microelements and MEMS deformation and 3-D surface profile analysis.
30 citations
TL;DR: In this article, a universal digital laser microinterferometer is presented, which can measure the shape, displacement, and strain and stress of microelements and microelectromechanical systems (MEMSs).
Abstract: A universal digital laser microinterferometer is presented, which can measure the shape, displacement, and strain and stress of microelements and microelectromechanical systems (MEMSs). This device can measure microelements with either a smooth or a rough surface. The method is based on laser interferometry (for smooth surfaces) and laser speckle interferometry (for rough surfaces), incorporating a diode laser, a long-distance microscope, a CCD camera, and a high-precision phase-shifting technique. The measuring system can be utilized to measure shape and out-of-plane displacement for samples with smooth surfaces, and with minor modification it can be applied to investigate out-of-plane and in-plane displacements for samples with rough surfaces. The theory and methodology of the universal digital laser microinterferometer are described. In particular, calibration and error compensation are introduced. The usefulness of the microinterferometer is demonstrated by examples of shape and displacement measurement for different MEMSs and microelements.
29 citations