Fig. 2: Experimental results.

a SKR versus launch power per fiber core. b SKR and QBER versus fiber length. Blue triangles: measured SKRs. Red triangles: measured QBERs in one fiber core as a function of fiber length, with counter-propagating classical signals at 18.3 dBm launched in the remaining three cores. Gray line: theoretical prediction. c Spatially aggregated throughput of 3 × 170 SDM and WDM classical channels. Triangles: generalized mutual information. Circle: decoded throughput