Results 111 to 120 of about 50,799 (157)
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Coherent and partially coherent twisting beams
Optical Review, 1994We present coherent and partially coherent beams that exhibit transverse pattern expansion and rotation upon free propagation. Coherent twisting beams may be generated by a suitable superposition of Laguerre-Gauss modes, while a model for partially coherent twisting beams is given by a continuous incoherent superposition of lowest order modes.
Franco Gori +5 more
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Coherent detection of partially coherent sources
Optics Letters, 1980The mean square of the beating component of the photodetector output current of a coherent optical or infrared receiver, illuminated by partially coherent quasi-monochromatic radiation, is expressed in terms of the mutual intensity functions of the signal and local reference fields on the detector’s active surface.
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Partially coherent nonparaxial beams
Optics Letters, 2004The concept of a partially coherent nonparaxial beam is proposed. A closed-form expression for the propagation of nonparaxial Gaussian Schell model (GSM) beams in free space is derived and applied to study the propagation properties of nonparaxial GSM beams.
Kailiang, Duan, Baida, Lü
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Partially coherent conical beams
Optics Letters, 2000We introduce a new class of partially coherent beams that can propagate over large distances without changing their transverse profiles and their coherence properties. Such beams are generated by an incoherent superposition of identical fully coherent beams of arbitrary form, whose axes lie on a cone.
A V, Shchegrov, E, Wolf
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Generalized Partial Directed Coherence
2007 15th International Conference on Digital Signal Processing, 2007This paper re-examines the definition of partial directed coherence (PDC) which was recently introduced as a linear frequency-domain quantifier of the multivariate relationship between simultaneously observed time series for application in functional connectivity inference in neuroscience.
Luiz A. Baccalá +2 more
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Symmetries in Coherent and Partially Coherent Fields
Optica Acta: International Journal of Optics, 1983The operator form of the solution for the wave equation is employed to indicate the symmetry properties of the diffracted field under coherent and partially coherent illumination. Such symmetries are of interest in holography, phase conjugation, and for automatic focusing.
A.W. Lohmann +2 more
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Coherence vortices in partially coherent beams
Optics Communications, 2003It is demonstrated that the spectral degree of coherence of a partially coherent beam may possess isolated pairs of points at which its phase is singular, and that in the neighborhood of these points the phase may possess a vortex structure. Partially coherent beams consisting of Hermite-Gaussian modes are considered as an example.
Gbur, G.J., Visser, T.D.
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Coherent diffractive imaging and partial coherence
Physical Review B, 2007We formulate coherent diffractive imaging in the framework of partially spatially coherent diffraction. We find that the reconstruction can be critically dependent on the degree of coherence in the illuminating field and that even a small departure from full coherence may invalidate the conventional assumption that a mapping exists between an exit ...
Williams, Garth J. +3 more
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On the Propagation of Coherent and Partially Coherent Light
Optica Acta: International Journal of Optics, 1979A comparison is made between the propagation of coherent light from a given field of a given geometry with the propagation of light from an incoherent field with the same geometry. This comparison illustrates the important relationship between the van Cittert-Zernike theorem and the normal diffraction calculation and how the intensity and degree of ...
Brian J. Thompson +1 more
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Non-diffracting partially coherent waves with binomial coherence
Journal of the Optical Society of America A, 2022Comprehensive analysis of non-diffracting optical waves with two-point binomial coherence function (BCF) is presented. This coherence function consists of two terms, each depending on either separation of points or the central point. We establish the necessary and sufficient conditions for nonnegative definiteness of the BCFs.
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