Free-space optical communication

The implementation of spatial multiplexing has become an area of great interest for free-space communication links, particularly for its use in last-mile links within larger optical networks. Light carrying orbital angular momentum (OAM) has emerged as a potential candidate that could be utilised for multiplexing independent channels. We experimentally study the turbulence-induced crosstalk between orbital angular momentum channels transmitted over a 1.6 km urban link [1-3]. Our results indicate that adaptive optical, or multiple-input and multiple-output (MIMO) techniques will be needed to overcome the crosstalk in such a link.

Figure 1: View from the receiver station of our free-space optical link across Erlangen


[1] C. Peuntinger, B. Heim, C. R. Müller, C. Gabriel, Ch. Marquardt, and G. Leuchs, “Distribution of Squeezed States Through an Atmospheric Channel”, Phys. Rev. Lett. 113, 060502 (2014).

[2] B. Heim, C. Peuntinger, N. Killoran, I. Khan, C. Wittmann, Ch. Marquardt, and G. Leuchs, “Atmospheric continuous-variable quantum communication”, New Journal of Physics 16, 113018 (2014).

[3] M. P. J. Lavery, B. Heim, C. Peuntinger, O. S. Magaña-Loaiza, E. Karimi, Th. Bauer, P. Banzer, Ch. Marquardt, A. E. Willner, R. W. Boyd, M. J. Padgett, and G. Leuchs, "Study of Turbulence Induced Orbital Angular Momentum Channel Crosstalk in a 1.6 km Free-Space Optical Link," in CLEO: 2015, OSA Technical Digest (online) (Optical Society of America, 2015), paper STu1L.4.

Project leaders:

Christoph Marquardt (MPL),
Gerd Leuchs (MPL),
Ebrahim Karimi (uOttawa),
Robert W. Boyd (uOttawa),

Other senior researchers:

Peter Banzer (MPL)
Dominique Elser (MPL)
Kaushik Seshadreesan (MPL)

External collaborators:

  • University of Rochester, USA: Omar S. Magaña-Loaiza, Robert W. Boyd
  • University of Glasgow, UK: Martin P. Lavery, Miles J. Padgett
  • University of Southern California, Los Angeles, USA:, Alan E. Willner
  • University of South Florida, Tampa, USA: Zhimin Shi
  • Friedrich-Alexander University Erlangen-Nürnberg (FAU), Germany