Simultaneous turbulence mitigation and channel demultiplexing for two 100 Gbit/s orbital-angular-momentum multiplexed beams by adaptive wavefront shaping and diffusing.

We experimentally demonstrate simultaneous turbulence mitigation and channel demultiplexing in a 200 Gbit/s orbital-angular-momentum (OAM) multiplexed link by adaptive wavefront shaping and diffusing (WSD) the light beams. Different realizations of two emulated turbulence strengths (the Fried parameter ${r_0} = 0.4,,1.0;{\rm mm}$r=0.4,1.0mm) are mitigated. The experimental results show the following. (1) Crosstalk between OAM $l = + 1$l=+1 and $l = - 1$l=-1 modes can be reduced by $ {\gt} {10.0}$>10.0 and $ {\gt} {5.8};{\rm dB}$>5.8dB, respectively, under the weaker turbulence (${r_0} = 1.0;{\rm mm}$r=1.0mm); crosstalk is further improved by $ {\gt} {17.7}$>17.7 and $ {\gt} {19.4};{\rm dB}$>19.4dB, respectively, under most realizations in the stronger turbulence (${r_0} = 0.4;{\rm mm}$r=0.4mm). (2) The optical signal-to-noise ratio penalties for the bit error rate performance are measured to be ${\sim}{0.7}$∼0.7 and ${\sim}{1.6};{\rm dB}$∼1.6dB under weaker turbulence, while measured to be ${\sim}{3.2}$∼3.2 and ${\sim}{1.8};{\rm dB}$∼1.8dB under stronger turbulence for OAM $l = + 1$l=+1 and $l = - 1$l=-1 mode, respectively.