Biomedical subjects

D Mendlovic

Publications and source records attributed to D Mendlovic.

5 recordsLinked to original sources

PubMed2001

Efficiency analysis of diffractive lenses.

Multilevel diffractive optical elements are necessary for achieving high-efficiency performance. Here the diffraction efficiency of a multilevel phase-only diffractive lens is analyzed. Approximate, as well as more accurate, approaches are presented. Both plane-wave and Gaussian illumination are discussed. It is shown that for many practical cases the diffraction efficiency can be determined by only a single parameter that takes into account the spatial bandwidth product as well as the focal length of the lens and the illumination wavelength. The analysis is based on the scalar theory and the thin-element approximation. Justification for doing this is presented. The results are valid for lenses with at least F/5.

Journal Article↗

PubMed2001

Two-dimensional optical wavelet decomposition with white-light illumination by wavelength multiplexing.

We present a novel method for achieving in real time a two-dimensional optical wavelet decomposition with white-light illumination. The underlying idea of the suggested method is wavelength multiplexing. The information in the different wavelet components of an input object is transmitted simultaneously in different wavelengths and summed incoherently at the output plane. Experimental results show the utility of the new proposed method.

Journal Article↗

PubMed2001

Optical implementation of second-order nonlinear Volterra operators with use of triple correlation.

Following the Volterra theorem, every nonlinear operator can be implemented with a sum of integrals applied over the input. The second-order Volterra operator that describes many useful systems can be related to a single integral that is a projection of an operation called the triple correlation. This operation may be easily implemented optically and thus be incorporated into fast real-time nonlinear control systems. We present a theoretical investigation of the relation existing between the Volterra operators and the triple correlation as well as an experimental demonstration that validates the theory.

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PubMed2000

Wigner-related phase spaces for signal processing and their optical implementation.

Phase spaces are different ways to represent signals. Owing to their properties, they are often used for signal compression and recognition with high discrimination abilities. We present several recently introduced Wigner-related sets of representations that have improved signal processing performance, and we introduce an optical implementation. This study deals with the generalized Wigner spaces, the fractional Fourier transform, and the x-p and the r-p representations. The optical implementations are demonstrated and discussed.

Journal Article↗

PubMed2000

Understanding superresolution in Wigner space.

Superresolution permits fine details to be observed that cannot be resolved by standard optical instruments. We demonstrate that superresolution is nothing more than an adaptation of degrees of freedom converted from the spatial domain to some other domains and vice versa. The tool used for the required conversion and adaptation is the Wigner chart. In addition, we show that the Wigner chart may be naturally applied for analyzing and understanding complex optical setups used for obtaining superresolution.

Journal Article↗