Special Joint OSE Seminar with Physics Colloquium by Prof. Alan Willner on High-Capacity Optical and Millimeter-Wave Communications using Multiple Orbital-Angular-Momentum Beams

Departmental News

Prof. Alan Willner 225 x 300

Posted: February 17, 2021

Date: Friday, February 19, 2021

Time:  3:30 PM to 4:30 PM

Location:  via Zoom

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Prof. Alan Wilner
University of Southern California


Prof. Willner is a world-renowned scientist in the field of photonics with numerous national and international awards recognizing his vast contributions to this field.  http://ee.usc.edu/~willner/     

Prof. Willner's talk, with an excellent mix of physics and engineering innovations, will showcase his group's recent outstanding achievements in utilizing light's orbital angular momentum (OAM) in optical (classical and quantum) free-space communication. 


Communications has historically experienced tremendous capacity growth by multiplexing many channels and transmitting them simultaneously. In this regard, space-division-multiplexing (SDM) as an exciting domain to exploit, and multiple spatially overlapping orthogonal modes can achieve a subset called mode-division-multiplexing (MDM). Indeed, the ability to multiplex multiple data-carrying modes over the same physical medium represents the potential for increasing system capacity and spectral efficiency.

Generating different amounts of orbital-angular-momentum (OAM) on different optical or millimeter-wave beams has emerged as a technique for such mode multiplexing in optical and radio communications. A beam can carry OAM if its phase front twists in a helical fashion as it propagates, and the amount of OAM corresponds to the number of 2*pi phase shifts that occur in the azimuthal direction. Each OAM beam is orthogonal to other beams, and such beams can be efficiently multiplexed, transmitted, and demultiplexed with little inherent crosstalk.

This presentation will explore the achievements of and challenges to OAM-based optical and millimeter-wave communication systems, including transmission, turbulence compensation, link design, causes and mitigation of modal crosstalk, and classical and quantum encoding.