University of Minnesota
School of Physics & Astronomy

Academic Calendar

Monday, April 16th 2018
Speaker:  Professor Sudhakar Prasad, University of New Mexico and University of Minnesota
Subject: The Modern Imaging Paradigm: There is Plenty of Room in the Middle

Every modern imaging system is comprised of optical, sensing, and computational modules that work in an integrated fashion to perform a dedicated imaging task as efficiently as possible. This new paradigm of imaging, called integrated or computational imaging, has enabled spectacular advances in probing remote objects and environments. I will illustrate this paradigm with an important application, namely Lord Rayleigh's classic resolution limit on the separability of two closely-spaced point sources from their images. I will show why such a limit has become a mere relic, one that has been usurped spectacularly by modern advances in image processing, new imaging methodologies, and ingenious work-arounds. Yet the best pair resolution that one can hope to achieve seems to be fundamentally limited by the number of signal photons available when making direct image measurements on the source pair. I will discuss a new approach of pair super-resolution that can qualitatively improve upon this seemingly insuperable photon limit, with quantum estimation theory revealing the ultimate bound on this phenomenon. Rather surprisingly, as I will also show, one can attain this quantum bound in certain limits in all three spatial dimensions with purely classical measurements that are not image based, but rather utilize coherent projections of the optical wave front. Phase does matter, even when imaging incoherent objects.

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