40-Gbit/s RZ-Signal Transmission in a Transparent Network Based on Wavelength-Selective Optical Cross Connect

We investigate 40-Gbit/s RZ-signal transmission in a transparent optical network equipped with wavelength-selective optical cross connects (WSOXC's). The investigation is performed in a re-circulating loop setup consisting of 4, 100-km spans of transmission fiber. A WSOXC is placed inside the loop to mimic cascaded WSOXC's with a spacing of 400 km. We study various degradation effects in the system, particularly those of node loss and optical filtering. Q-value measurements of the received signal were carried out at different transmission distances and WSOXC loss conditions. A Q-value of 15.5 dB was measured at 1200-km distance with two cascaded WSOXC's of which the node loss is 17 dB.