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Updated: Sep 11, 2025

Simultaneous Measurement of Turbulence and Particle Kinematics Using Flow Imaging Techniques
Published on: March 12, 2019
Two-mode averaging for turbulence resilience
Abstract:
Atmospheric turbulence typically impairs free-space optical communication systems, particularly those using mode-division multiplexing, by causing detrimental crosstalk among higher-order modes. This interaction can also be harnessed through mode averaging at the receiver and transmitter to passively counteract turbulence effects. Mode averaging involves the simultaneous transmission and detection of multiple, strategically selected modes. Prior research on mode averaging-often referred to as modal diversity-primarily selected modes by using the spread of crosstalk among modes. In this study, we show that it is crucial to include the impact of mode-dependent loss. This is demonstrated by identifying optimal two-mode combinations that maximize received power while efficiently utilizing mode space. The optimal combinations assessed include pairs of orbital angular momentum (OAM), Laguerre-Gaussian (LG), and Hermite-Gaussian (HG) modes, as well as mixed pairs of LG and HG modes. Interestingly, it is shown that the optimal combinations are not always the neighboring modes.
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