Paper
1 April 1992 Reconstruction of phase and amplitude components of diffraction field resulting from light scattering by an object using hologram without reference beam
Igor I. Mokhun, S. N. Roslyakov, V. V. Yatsenko
Author Affiliations +
Proceedings Volume 1723, LAMILADIS '91 Intl Workshop: Laser Microtechnology and Laser Diagnostics of Surfaces; (1992) https://doi.org/10.1117/12.58656
Event: LAMILADIS '91: International Workshop: Laser Microtechnology and Laser Diagnostics of Surfaces, 1991, Chernivsti, Ukraine
Abstract
Holographic methods have been widely used in surface testing, the principal methods being the recording and reconstruction of the information on the surface under investigation, the measurement of the changes of the surface and the surrounding medium, and the holographic interferometry. The holography without reference beam (HWRB) has received little attention in this respect, although it possesses all the advantages of the commonly used holographic methods. Some of the applications of the HWRB and the holography with a local reference beam have been reported in the literature. The present paper is an attempt to investigate the applicability of the HWRB for surface testing. The feasibility of the HWRB and the reconstruction of the object field from such a hologram has been demonstrated by Van Heerden. The reconstruction is usually performed by a part of the field scattered by an object, by virtue of the HWRB selectivity. This selectivity amounts to definition of a useful signal against the background due to coherent addition of the image points and noise intensities. The associative properties of an HWRB, i.e., the reconstruction of the entire object field from its part, have been reported. However, such an associativity reduces to a minimum the advantages of HWRB since the reconstruction of the object field requires the actual presence of the object. Moreover, the illumination conditions must be identical to those during the recording of the hologram. We propose a somewhat different approach to the above associativity. To reconstruct a field, a set of reconstructing sources whose characteristics are the same as those of a set of object field sources is required. Such a reconstructing source is characterized by its coordinates, radiation phase, size, amplitude modulation, and polarization. These characteristics affect the object field reconstruction process differently. Thus, the polarization of a source has no effect on the signal-to-noise ratio, determining only the overall intensity of the reconstructed field. The amplitude modulation is also found to be insignificant for the reconstruction of a signal from a HWRB. This is evident from the experiment where the amplitude modulation is accomplished by means of a transparency placed in an immersion liquid. During the hologram reconstruction the amplitude transparency is replaced by another one. A drop in the phantom image intensity can be attributed to the fact that the original phase relationships could not be completely retained.
© (1992) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Igor I. Mokhun, S. N. Roslyakov, and V. V. Yatsenko "Reconstruction of phase and amplitude components of diffraction field resulting from light scattering by an object using hologram without reference beam", Proc. SPIE 1723, LAMILADIS '91 Intl Workshop: Laser Microtechnology and Laser Diagnostics of Surfaces, (1 April 1992); https://doi.org/10.1117/12.58656
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