REDUCTION OF OPTICAL-BEAT INTERFERENCE IN SUBCARRIER NETWORKS

We present a method for improving the performance of a subcarrier mult iplexed passive optical network (SCM-PON) in the presence of optical b eat interference (OBI), By introducing strong ''clipping tones'' (opti cal-modulation depth > 1) on each of the lasers their optical spectrum can be broadened, thereby ameliorating the effects of OBI. By careful ly selecting the RF band used to carry signals, and that used for ''cl ipping tones,'' OBI can be reduced without the clipping inducing error s, We have demonstrated the effectiveness of this technique by measuri ng the BER of a QPSK channel in the presence of OBI, A delayed self-ho modyne technique was used to simulate worst-case conditions.