We have developed a method to obtain a set of spectral components of three-dimensional (3D) images for a spatially incoherent, polychromatic light source distribution by a fully passive interferometric technique. The principle of the method is based on the measurement of a five-dimensional (5D) spatial coherence function and signal processing including the synthetic aperture technique and spectral decomposition. This paper gives a mathematical formulation illustrating the principle of the method, and we report an experimental demonstration in which the measured object is composed of two statistically uncorrelated point sources. The experimental results verify the applicability of our method to conventional spatially incoherent, polychromatic objects.
interferometry spectrometry digital holography coherence synthetic aperture technique