Adaptive optics compensation of multiple orbital angular momentum beams propagating through emulated atmospheric turbulence

We propose an adaptive optics compensation scheme to simultaneously compensate multiple orbital angular momentum (OAM) beams propagating through atmospheric turbulence. A Gaussian beam on one polarization is used to probe the turbulence-induced wavefront distortions and derive the correction pattern for compensating the OAM beams on the orthogonal polarization. By using this scheme, we experimentally demonstrate simultaneous compensation of multiple OAM beams, each carrying a 100 Gbit/s data channel through emulated atmospheric turbulence. The experimental results indicate that the correction pattern obtained from the Gaussian probe beam could be used to simultaneously compensate multiple turbulence-distorted OAM beams with different orders. It is found that the turbulence-induced crosstalk effects on neighboring modes are efficiently reduced by 12.5 dB, and the system power penalty is improved by 11 dB after compensation.