“The Effects of Deep Turbulence in the Atmosphere on Propagating Laser Beams and How to Characterize and Correct These Effects”

Location: LTS Auditorium, 8080 Greenmead Drive

Speaker:
Christopher C. Davis
Professor, Department of Electrical and Computer Engineering

Abstract:
When laser beams propagate on relatively long paths (1-5 km.) in the low atmosphere they experience what is called “deep” turbulence. The laser beam becomes severely distorted, and breaks into multiple patches. The characterization and correction of these effects is very important for free space optical communication systems and for laser weapons systems.

This talk will describe the use of plenoptic sensors and the
phenomenon of enhanced backscatter for characterizing the beam distortions and providing information to an adaptive optics system to correct these distortions. The plenoptic sensor also allows improved imagery to be obtained through a distorting atmosphere. The
challenges of using coherent combining of high power lasers as a means for correcting overall beam distortion on a distant target will also be discussed.

Bio:
Christopher C. Davis is the Minta Martin Professor of Engineering and a professor of electrical and computer engineering at UMD.

From 1973-1975, he was an instructor/research associate at Cornell University, and from 1982-83 was a senior visiting fellow at the University of Cambridge.

Davis is a Fellow of both the Institute of Physics and the IEEE.

He is the author of the widely used text “Lasers and Electro-Optics,” published by Cambridge University Press, and co-author with Jack Moore and Mike Coplan of the best-selling text “Building Scientific Apparatus,” now in its fourth edition.

Davis is author or co-author of 14 book chapters, more than 245 refereed journal articles and over 300 conference papers, and is editor of 10 volumes of SPIE Proceedings.

He holds 16 awarded and several pending patents. Currently, his research focuses on optical and directional RF wireless, directed energy, optical sensors, hybrid networks, laser interferometry, dielectrometry, atmospheric turbulence, optical communication systems and devices, and biophysics.

Davis received his doctorate in physics from the University of Manchester.