OSC Colloquium: Michael Gehm, "Toward ‘One-Way Smoke’: Engineering Asymmetric Vision in a Reciprocal Aerosol Environment"

Title

Toward ‘One-Way Smoke’: Engineering Asymmetric Vision in a Reciprocal Aerosol Environment

Abstract

Aerosols, in sufficient concentrations, dramatically impact light transport and imaging through a combination of scattering and absorption processes. Over the years, there has been considerable research on methods on imaging through such high-extinction environments. Recently, a DARPA program, “Coded Visibility,” posed the question of whether the aerosol particles and plume environment could be engineered in a way to facilitate asymmetric vision—an environment where it is easier to image in one direction than its reverse—effectively, creating ‘one-way smoke.’ At first glance, it seems an asymmetric vision capability might violate basic electromagnetic reciprocity, which is often colloquially described as “if I can see you, you can see me.” However, there are a variety of reasons why this colloquial description does not fully capture the constraints of reciprocity, and, in fact, asymmetric vision does not appear to be fundamentally prohibited. In this talk I will discuss our investigation of the general feasibility of this phenomenon as well as our explorations into several promising engineered scenarios that seek to exploit this opportunity. In addition to our ongoing work, I will introduce a variety of interesting open questions that have emerged during our efforts.

Bio

Michael Gehm received his BS in Mechanical Engineering from Washington University, St. Louis and his AM and PhD in Physics from Duke University for experimental study of degenerate Fermi gases. Following a postdoctoral appointment where he studied computational sensing, he served as an Assistant and then Associate Professor in the ECE Department at the University of Arizona. He is now Professor of Electrical and Computer Engineering and Physics at Duke University. His research interests include computational sensing and imaging, imaging through turbid media, x-ray imaging, and fundamental optical physics. He is a Fellow of both Optica and SPIE.

Contact

Florian Willomitzer, Colloquium Chair & Professor: colloquium@optics.arizona.edu