KIM FOOK LEE |
RESEARCH |
Optical Phase-Space Tomography
The OPST is the measurement of the Wigner phase space distribution of an optical field. The Wigner distribution is Fourier Transform related to the two-point mutual coherence function. Wigner phase-space and time-frequency distribution can be used to describe an image of a particle with the size ranging from Planck’s constant to 10-6 m. Wave-particle features of Wigner distributions, related to optical coherence, may survive over distances that are large compared to the transport mean free path. However, the physical nature of these features is not yet clear. Elucidation of these contributions could strongly impact extended-depth, high-resolution coherence tomography. Another advantage is that Wigner phase-space distributions could bridge the gap between phenomenological transport equations and rigorous wave equation treatments. 
Since rigorous transport equations can be derived for Wigner distributions, they are essential for obtaining fundamental new insights into the nature of light propagation in turbid media. Evolution equations for Wigner distributions, which include optical coherence scatterings, are generally non-local and are relatively unexplored. With suitable approximations, these non-local equations reduce to the usual radiative transport equations. Establishing the physical relationship between Wigner distributions and the phenomenological specific intensity will impact most existing methods of imaging in multiple scattering media. Further, the Wigner distribution includes statistically averaged over coherent and incoherent contributions of the scattered lights and rigorously incorporates into phase and intensity information. Hence, measurement of the Wigner distribution will lead to new avenues in optical imaging.
Quantum Communication and Computing using Non-Classical Light |
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