Experimental comparison of mid-link spectral inversion and conventional DCF-based transmission in a DWDM system at 40Gbit/s

In this paper, the performance of mid-link spectral inversion (MLSI)-based transmission is quantitatively compared to the performance for 'conventional' dispersion compensating fiber (DCF)-based transmission. Bit error rates (BER) are measured at optimized residual dispersion for all sixteen channels after 800km transmission in standard single mode fiber (SSMF). We show that for the MLSI-based configuration up to a decade of improvement in BER is obtained compared to the DCF based system. MLSI has the potential of lowering the cost of long haul transmission systems since instead of having multiple DCF modules per span only one spectral inverter is required for the whole transmission line. For spectral inversion, a polarization independent magnesium-oxide-doped periodically-poled lithium-niobate (MgO:PPLN) based subsystem was used.