Shape and deformation measurement of diffusely reflecting 3D objects are very important in many application areas, including quality control, nondestructive testing, and design. When rough objects are exposed to coherent beams, the scattered light produces speckle fields. A method to measure the shape and deformation of 3D objects from the sequential intensity measurements of volume speckle field and phase retrieval based on angular-spectrum propagation technique is described here. The shape of a convex spherical surface was measured directly from the calculated phase map, and micrometer-sized deformation induced on a metal sheet was obtained upon subtraction of the phase, corresponding to unloaded and loaded states. Results from computer simulations confirm the experiments.
"Another application can be found in mechanics in measurement of the roughness , shape , and slope  of the object under investigation. Speckle effect also plays a significant role in continuum mechanics especially in measuring of small changes of a state of an object's surface [6–11]. The deformation state of an elementary area of the object's surface can be determined by the small deformation tensor with translation, rotation, and deformation components (ax, ay, az), (Ωx, Ωy, Ωz), and (εxx, εxy, εyy), respectively . "
[Show abstract][Hide abstract] ABSTRACT: The purpose of the study is to show a proposal of an extension of a one-dimensional speckle correlation method, which is primarily intended for determination of one-dimensional object's translation, for detection of general in-plane object's translation. In that view, a numerical simulation of a displacement of the speckle field as a consequence of general in-plane object's translation is presented. The translation components a x and a y representing the projections of a vector a of the object's displacement onto both x- and y-axes in the object plane (x, y) are evaluated separately by means of the extended one-dimensional speckle correlation method. Moreover, one can perform a distinct optimization of the method by reduction of intensity values representing detected speckle patterns. The theoretical relations between the translation components a x and a y of the object and the displacement of the speckle pattern for selected geometrical arrangement are mentioned and used for the testifying of the proposed method's rightness.
The Scientific World Journal 01/2014; 2014:704368. DOI:10.1155/2014/704368 · 1.73 Impact Factor
"The radiation system 1 is the basis of all optical setups. The sources of various spectral range (from visible to X-ray) both monochromatic      and multispectral   may appear there. The next necessary element of the setups is an investigated object 2. Nowadays it can be very diverse: transmitting  and reflective , the amplitude with phase noise, pure phase, amplitude-phase, self-illuminated . "
[Show abstract][Hide abstract] ABSTRACT: Additional datasets allow the wavefront phase retrieval by the iteration procedure. They can be obtained in practice using the set of parameters in the phase analyzer, radiation and registration systems of the phase retrieval setups.
[Show abstract][Hide abstract] ABSTRACT: Three dimensional microscopy allows the reconstruction of both phase and amplitude of the object wavefronts. This in turn sheds information on the optical path length profile of the object. Conventionally 3D microscopy is achieved using two beam interference techniques, which requires adjustment of the beam for high quality interference fringes as well as is more prone to external vibrations. Here we discuss a single beam 3D microscopic technique. The technique works by sampling the volume speckle field generated by putting a diffuser in the path of the probe beam passing through the object at several axial planes and computing the complex amplitude of the object wavefront using angular spectrum approach towards scalar diffraction theory.
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