title: Mode-Division-Multiplexing of Multiple Bessel-Gaussian Beams Carrying Orbital-Angular-Momentum for Obstruction-Tolerant Free-Space Optical and Millimetre-Wave Communication Links.
abstract: We experimentally investigate the potential of using 'self-healing' Bessel-Gaussian beams carrying orbital-angular-momentum to overcome limitations in obstructed free-space optical and 28-GHz millimetre-wave communication links. We multiplex and transmit two beams (l = +1 and +3) over 1.4 metres in both the optical and millimetre-wave domains. Each optical beam carried 50-Gbaud quadrature-phase-shift-keyed data, and each millimetre-wave beam carried 1-Gbaud 16-quadrature-amplitude-modulated data. In both types of links, opaque disks of different sizes are used to obstruct the beams at different transverse positions. We observe self-healing after the obstructions, and assess crosstalk and power penalty when data is transmitted. Moreover, we show that Bessel-Gaussian orbital-angular-momentum beams are more tolerant to obstructions than non-Bessel orbital-angular-momentum beams. For example, when obstructions that are 1 and 0.44 the size of the l = +1 beam, are placed at beam centre, optical and millimetre-wave Bessel-Gaussian beams show ~6 dB and ~8 dB reduction in crosstalk, respectively.
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Nisar
authors.initials: N
authors.lastname: Ahmed
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Long
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Huang
authors.affiliation: School of Engineering, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
authors.forename: Martin P J
authors.initials: MP
authors.lastname: Lavery
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Peicheng
authors.initials: P
authors.lastname: Liao
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Guodong
authors.initials: G
authors.lastname: Xie
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Yongxiong
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Almaiman
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Asher J
authors.initials: AJ
authors.lastname: Willner
authors.affiliation: NxGen Partners, Dallas, Texas 75219, USA.
authors.forename: Solyman
authors.initials: S
authors.lastname: Ashrafi
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Andreas F
authors.initials: AF
authors.lastname: Molisch
authors.affiliation: School of Electrical Engineering, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Moshe
authors.initials: M
authors.lastname: Tur
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Alan E
authors.initials: AE
authors.lastname: Willner