Dr. Andrew Barentine, Stanford University

Library, A.2.500, Staudtstraße 2

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Abstract: Stimulated emission (StE) has served as a valuable tool in biological imaging as a quenching mechanism for fluorescence, yet has itself remained relatively unused as an image-forming signal. Often thought of as a photon-copying mechanism, StE has potential speed and resolution advantages over fluorescence as an imaging contrast due to it being driven-by and coherent-with an experimentally controlled field (the probe). The ultimate problem in imaging StE is how to detect the StE light generated in the sample without also detecting the probe, which is typically a powerful laser. Unsolved, this problem contaminates StE images with the shot noise (and technical noise) of the probe laser, which is orders of magnitude higher than the StE signal that can typically be generated with a single organic dye molecule, blocking the possibility of single-molecule imaging. Here, we use simultaneous detection of fluorescence depletion as a rigorous control and calibration for the previously-developed approach to transmission StE imaging, whose sensitivity limit is bounded by the shot noise of the probe. With the same controls, we then attempt to detect StE without the background of the probe, the success of which could ultimately open the possibility of single-molecule StE imaging.

Bio: Andrew E. S. Barentine is a postdoctoral scholar in the lab of W.E. Moerner at Stanford, where he is developing stimulated emission detection methods. This work builds on his passion for high-throughput light microscopy, a field he explored during his PhD advised by Joerg Bewersdorf at Yale and co-advised by David Baddeley at University of Auckland. Originally from Colorado, Andrew began his research career as an undergraduate assistant in the Cornell group at JILA (CU Boulder), so it might not surprise you that he has a soft spot for mountains and bikes in addition to lasers.