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Speckle imaging

About: Speckle imaging is a research topic. Over the lifetime, 3730 publications have been published within this topic receiving 62354 citations.


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Journal ArticleDOI
TL;DR: A dual in-plane electronic speckle pattern interferometry system has been developed for in situ measurements, and the overall system is controlled by advanced software, which allows switching between the two perpendicular planes in quasi real time.
Abstract: A dual in-plane electronic speckle pattern interferometry (ESPI) system has been developed for in situ measurements. The optical setup is described here. The system uses an electro-optical switch to change between the illumination directions for x and y sensitivity. The ability of the electro-optic device to change the polarization of the laser light forms the basis of this switch. The electro-optic device is a liquid-crystal layer cemented between two optically flat glass plates. An electric field can be set up across the layer by application of a voltage to electrodes. The speckle interferometry system incorporates two additional liquid-crystal devices to facilitate phase shifting, and the overall system is controlled by advanced software, which allows switching between the two perpendicular planes in quasi real time. The fact that there are no moving parts is an advantage in any ESPI system for which mechanical stability is vital.

22 citations

Journal ArticleDOI
TL;DR: In this paper, two measurements performed on rough surfaced objects are described, one on a mechanical component with a rather difficult accessible surface to be measured and the other on a convex surface of a ground lens.

22 citations

Proceedings ArticleDOI
27 May 2003
TL;DR: In this article, the size distribution of speckle is discussed from physical viewpoints and the dynamic behaviors of the sparsification of diffuse surfaces are described. And applications of these properties of specks to measurement of displacement and deformation are discussed.
Abstract: Speckle arises from interference of many waves with random phase relationship. In spite of its random appearance its statistical properties are independent of surface roughness of diffusers and depend only on macroscopic parameters of optical systems under usual conditions of observation. In this article we first discuss the size distribution of speckle from physical viewpoints. Then we describe the dynamic behaviors of speckle that are caused by displacement and deformation of diffuse surfaces as well as by change in optical system. Finally we overview applications of these properties of speckle to measurement of displacement and deformation.

22 citations

Journal ArticleDOI
TL;DR: An overview of some recent progress in digital speckle interferometry and its application for vibration measurement in the automotive industry is presented and how powerful this tool is for whole vehicle modal survey, interactive design optimization, CAE model correlation, and nondestructive testing is demonstrated.
Abstract: This paper presents an overview of some recent progress in digital speckle interferometry and its application for vibration measurement in the automotive industry. It describes three methods to generate raw vibration fringe patterns with better quality; provides speckle averaging, phase shifting, and phase reconstruction iteration procedures to produce a high-quality and noise-free fringe pattern; illustrates one single setup for measuring both vibration deformation and geometric shape of an object; and demonstrates how powerful this tool is for whole vehicle modal survey, interactive design optimization, CAE model correlation, and nondestructive testing. Finally, areas for further development are suggested.

22 citations

Journal ArticleDOI
TL;DR: A procedure that will reduce the number of frames required for the analysis of the time-averaged fringe pattern of TV holographic system used and the experimental results obtained on an edge-clamped, sinusoidally excited square aluminium plate sample are discussed.
Abstract: Time-average TV holography is widely used method for vibration measurement. The method generates speckle correlation time-averaged J0 fringes that can be used for full-field qualitative visualization of mode shapes at resonant frequencies of an object under harmonic excitation. In order to map the amplitudes of vibration, quantitative evaluation of the time-averaged fringe pattern is desired. A quantitative evaluation procedure based on the phase-shifting technique used in two beam interferometry has also been adopted for this application with some modification. The existing procedure requires a large number of frames to be recorded for implementation. We propose a procedure that will reduce the number of frames required for the analysis. The TV holographic system used and the experimental results obtained with it on an edge-clamped, sinusoidally excited square aluminium plate sample are discussed.

22 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202332
202249
202162
202079
201972
201895