Sculpting Light in 3D with Femtosecond Sources

Rapid progress in ultrafast laser technology has opened new experimental possibilities in biology and neuroscience. Intense short pulses can induce multiphoton absorption to activate fluorescent probes and photosensitive modulators precisely in 3D in individual cells, and infrared light can penetrate deep into tissue without major absorption or distortion issues. With these two major advantages, multiphoton microscopy is a popular approach to monitor and manipulate living tissue. My laboratory at UNC chapel hill tackles the challenge of turning advanced light sources into practical devices with an interdisciplinary approach at the intersection between optical engineering, computer science, and neuroscience to build optical brain machine interfaces. In this talk, we will discuss recent progress in the development of algorithms that can rapidly

custom 3D illumination patterns, and precisely stimulate distributed groups of cells, and new optical systems that preserve the spatial and temporal confinement of short pulses to maximize two-photon absorption. We will present DeepCGH, our latest algorithm for fast 3D computer generated holography. We will also show how it can be integrated in a precise photostimulation device using 3D-SHOT, a technique that combines computer generated holography and temporal focusing to concentrate photostimulation in cell-sized domains and further enhance spatial resolution.

Nicolas Pégard

Assistant Professor, UNC Chapel Hill on September 11, 2020 at 10:00 AM in Zoom Webinar
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Nicolas Pégard is an Assistant Professor in the Dept. of Applied Physical Sciences at UNC Chapel Hill, with courtesy affiliations in the Dept. of Biomedical Engineering, and at the UNC Neuroscience center. Prior to joining UNC in 2019, Prof. Pégard was a Postdoctoral scholar in the Depts. of EECS, and Molecular and Cell Biology at UC Berkeley. He received a Ph.D. in Electrical Engineering from Princeton University in 2014 and graduated from Ecole Polytechnique in France before that. He is the recipient of the 2018 Career Award at the Scientific Interface (Burroughs Wellcome Fund), and a 2017 outstanding postdoc award. Prof Pégard is a senior member of the Optical Society and a founding member of Sculpted Light in the Brain (, a nonprofit that organizes conferences on optical neurotechnology, promotes interdisciplinary research between junior and senior scientists, and provides travel grants to early-career and underrepresented scientists.

Electrical and Computer Engineering Colloquia

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