Paper
29 January 1988 Nonimaging Techniques For The Extraction Of Noncoherent Object Information And Its Processing
A. S. Marathay
Author Affiliations +
Abstract
The Van Cittert-Zernike theorem from the theory of partial coherence provides a Fourier relationship between the intensity distribution of a plane noncoherent object and the spatial coherence function of the light in a plane illuminated by the object. Although the spatial coherence function has the dimensions of optical intensity, it is not directly accessible to measurement. Information about the real and imaginary parts or the absolute value and the phase argument of the spatial coherence function permits us to derive the intensity distribution of the noncoherent planar object. In this paper, two methods of obtaining information on the complex-valued spatial coherence function are discussed. In the first method, we review briefly the determination of the cosine and the sine of the phase argument using triple- and quadruple-intensity correlations. Combined with the intensity interferometry of Hanbury Brown and Twiss which measures the square of the absolute value of the normalized coherence function, this provides sufficient information to derive the intensity distribution of the noncoherent object. In the second method we show how a hologram of a noncoherent object, referred to as a r hologram, is formed by encoding the complex-valued spatial coherence function on a photographic film. This record is made possible by means of a self-referencing interferometer. Such a record behaves much like a hologram; it permits reconstruction of the noncoherent source object with the aid of the same interferometric arrangement. This procedure opens new possibilities of noncoherent-object information processing such as matched filtering and spatial-frequency filtering.
© (1988) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
A. S. Marathay "Nonimaging Techniques For The Extraction Of Noncoherent Object Information And Its Processing", Proc. SPIE 0828, Digital Image Recovery and Synthesis, (29 January 1988); https://doi.org/10.1117/12.942087
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KEYWORDS
Holograms

Spatial coherence

Mirrors

Photography

Interferometers

Image restoration

Optical signal processing

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