Optical Measurements,Modeling and Metrology

Measurement of Residual Stresses In Diamond Coated Substrates Utilizing Coherent Light Projection Moire Interferometry

Abstract Thin film technology is an area of great importance in current applications of opto-electronics, electronics, MEMS and computer technology. A critical issue in thin film technology is represented by residual stresses that arise when thin films are applied to a substratum. Residual stresses can be very large in magnitude and may result in detrimental […]

Automatic Acquisition and Processing of Large Sets of Holographic Measurements in Medical Research

ABSTRACT We are developing an advanced computer-controlled digital opto-electronic holographic system (DOEHS) with the ability to operate in several modalities, including optoelectronic holographic microscopy, lensless digital holography, speckle pattern interferometry, and fringe projection. The DOEHS is being designed for medical applications requiring full-field-of-view information of shape and deformations to aid in the diagnosis and investigation […]

Adaptative reconstruction distance in a lensless Digital Holographic Otoscope

ABSTRACT We are developing a Digital Optoelectronic Holographic System (DOEHS) for measurements of shape and deformations acoustically induced of the human tympanic membrane (TM) in the clinic. Such measurements will be used to perform quantitative diagnosis of the middle-ear. The DOEHS platform consists of laser-delivery illumination (IS), optical head (OH), image-processing computer (IP), and positioning […]

3D Shape Measurements with High-Speed Fringe Projection and Temporal Phase Unwrapping

Abstract The abilities to increase precision of surgical procedures by tracking real-time motions, accurately measuring the mechanical properties of complex 3D geometries, and tracking deformations of components over time, among many other applications, depend on the availability of robust, high-speed, full-field-of-view, 3D shape measurement systems. In this paper, we present advances in our development of […]

Measuring Local Mechanical Properties of Membranes Applying Coherent Light Projection Moire Interferometry

Abstract The bulge test is a versatile and reliable way to determine mechanical properties of thin films. It can be applied to obtain constitutive equations of the material at different ranges of deformation including time effects. It provides a biaxial state of stresses that is the prevailing condition in thin film operate. In this paper […]

Experimental Analysis of Foam Sandwich Panels With Projection Moire

Abstract The use of polymeric and metallic foam sandwich panels in naval, aerospace, railway and automotive constructions is rapidly growing in the recent years because of technological improvements in manufacturing processes. However, it is still difficult to establish a direct relationship between the mechanical properties possessed by the panel and the specific manufacturing process. Mechanisms […]

Panoramic stereo DIC-based strain measurement on submerged objects

ABSTRACT In this paper, we describe a theoretical foundation for and experimental implementation of a novel 360-degree stereo digital image correlation (DIC) method for quantifying shape and deformation of quasi-cylindrical specimens along their full length and around their circumference. The proposed approach has been implemented for in-vitro experiments on arteries immersed within a physiologic solution […]

Advances in the Measurement of Surfaces Properties Utilizing Illumination at Angles Beyond Total Reflection

Keywords: evanescent waves, surface roughness, high accuracy topography Abstract In preceding papers the authors have employed evanescent illumination to perform measurement of depth information on rough surfaces. In the developments presented in this paper new experimental evidence has been gathered. This information provides additional elements that help to formulate a more complete model of the […]

Filters with Noise/Phase Jump Detection Scheme for Image Reconstruction

ABSTRACT Residual noise, speckle noise, and noise at the lateral surface of height discontinuities influence the image reconstruction in the wrapped phase map of a 3D object containing the height discontinuities. This paper develops two robust filters, namely Filters A and B, in order to resolve these noise problems. A previously proposed noise/phase jump detection […]

An Instantaneous Phase Shifting ESPI System for Dynamic Deformation Measurement

ABSTRACT In this study, an ESPI measurement system which is capable of grabbing four phase-shifted interferometric images instantaneously (or simultaneously) is developed for out-of-plane dynamic deformation measurement. A new polarization phase-shifting interferometric system is designed. The system constructed allows the four phase-shifted images to be grabbed by four CCD simultaneously. And digital image correlation method […]

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