"Entanglement-Assisted Communication over Turbulent Optical Channels"

Abstract: Entanglement represents a unique quantum information feature offering distinct advantages for a wide range of communication and sensing applications. While nondegenerate entanglement assisted (EA) communication schemes have been proven effective, they typically require optical phase conjugation (OPC), often performed on weak signal photons that are subject to degradation from scattering, absorption, diffraction, and turbulence in free-space optical (FSO) channels. To solve this problem, we recently proposed two approaches: (i) to perform the OPC on bright idler photons and (ii) to employ a degenerate EA concept. In this talk, we review our recent approaches to both nondegenerate and degenerate EA communications over turbulent FSO channels. For degenerate EA communications we describe two approaches. In the first approach, we rely on a costly and bulky 780 nm narrow-linewidth pump laser. In the second approach, we leverage two independent, low-cost telecom pump lasers operating in the C- and L-bands, which in combination with the type-0 PPLN waveguide can generate bright entangled photon pairs in the L-band. To demonstrate the proposed EA communication concepts, we conducted a series of experiments over a 1.5 km terrestrial FSO link on the University of Arizona campus. Experimental results indicate that the proposed EA systems are significantly more tolerant to turbulence effects compared to corresponding classical laser communication counterparts, particularly in strong atmospheric turbulence regime.

Prof. Ivan B. Djordjevic

ECE Department, FAMU-FSU COE

Speaker Bio: Ivan B. Djordjevic is a professor of electrical and computer engineering (ECE) and quantum information science at the Department of Electrical and Computer Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, where he directs Quantum Communications, Sensing, and Networking Lab.  He received his PhD degree from the University of Nis, Yugoslavia in 1999. Dr. Djordjevic is both the IEEE Fellow and the Optica (formerly OSA) Fellow. Professor Djordjevic has authored or co-authored 13 books, more than 620 journal and conference publications, and he holds 58 US patents. He has served as Area Editor/Associate Editor/Member of Editorial Board/Guest Editor for: IEEE Transactions on Communications, Optica/IEEE Journal of Optical Communications and Networking, IEEE Communications Letters, IOP Journal of Optics, Elsevier Physical Communication (PHYCOM) Journal, Optical and Quantum Electronics, Frequenz, IEEE Signal Processing Magazine, Entropy, and IEEE/Optica Journal of Lightwave Technology. Prior to joining the Florida State University, Dr. Djordjevic held appointments at University of Arizona in Tucson, University of Bristol and University of the West of England in UK, Tyco Telecommunications in USA, National Technical University of Athens in Greece, and State Telecommunication Company in Yugoslavia.