Abstract
A single multi-plane light convertor (MPLC) is applied to simultaneously mitigate turbulence-induced crosstalk and demultiplex two orbital angular momentum (OAM) multiplexed channels for a free-space optical link. Comprised of six programmable phase planes, the MPLC is placed at the receiver side for turbulence mitigation and channel demultiplexing. Propagating through the cascaded phase planes, two coaxial turbulence-distorted OAM beams each carrying one data channel are shaped and sorted into two differently positioned Gaussian beams with low inter-channel crosstalk. As an experimental demonstration, one MPLC adaptively mitigates the turbulence-induced crosstalk by up to 26 dB for two OAM-multiplexed channels (ℓ = {−1, +2}). Two 100-Gbit/s quadrature-phase-shift-keying (QPSK) channels are recovered with an up-to-1.5-dB optical signal-to-noise ratio (OSNR) penalty under one turbulence realization.
•Turbulence mitigation and channel demultiplexing using an MPLC in an FSO link.•The MPLC mitigates the turbulence-induced crosstalk for two OAM-carried channels.•Two 100-Gbit/s QPSK channels each carried by an OAM beam are recovered by the MPLC.