Experimental investigation of nonlinear noise in long-haul 100-Gb/s DP-QPSK communication systems using real-time DSP

Nonlinear noise in 100-Gb/s dual-polarization quadrature phase shift keying transmission has been investigated using a straight-line test bed. The optimal signal power and OSNR margin have been measured in up to 4000 km of G.652-fiber. The results have a good agreement with previously reported models.