Mutual deterioration of WDM-coupled AM-CATV and digital B-ISDN services in single fiber access networks

In single-fiber access networks with interactive and distributive services multiplexed at different wavelengths, the interactive signal may disturb the distributive signal, and vice versa, because of imperfect isolation of the demultiplexing WDM at the subscriber site. The mutual deterioration of a 622-Mb/s intensity-modulated (IM) broadband ISDN (B-ISDN) signal at 1.3 mu m and an AM subcarrier-multiplexed (SCM) TV-distribution signal at 1.55 mu m is investigated. Both theory and experiment show that the isolation of the demultiplexing WDM must keep the undesirable 1.3- mu m, 622-Mb/s IM signal power on the analog receiver below -36 dBm to avoid degradation of the analog system CNR of 47 dB by more than 1 dB.<>