Experimental results are presented for the first time of Q penalties resulting from multiple passes through commonly available fixed optical add-drop multiplexers (OADMs) in a 50-GHz channel plan at 10 Gbit/s. We find that transmission through >6 OADMs is feasible within a laser center frequency range of ±2.5 GHz with a Q penalty of <1 dB. We find expressions for the Q penalty contributions from distortion-induced eye closure and optical signal-to-noise ratio (OSNR) degradation and show that the predicted penalty functions from these components fit very well the measured Q penalty as a function of laser-frequency offset within a filter passband. Both contributions are necessary for accurately predicting the total Q penalty.
© 2004 Optical Society of AmericaPDF Article