High-speed bidirectional four-channel optical FDM-NCFSK transmission using an Er/sup 3+/-doped fiber amplifier

A four-channel optical frequency division multiplexed-noncoherent frequency-shift keying (FDM-NCFSK) bidirectional transmission experiment using an Er/sup 3+/ doped fiber amplifier at 1.7 Gb/s for 100 km fiber length is demonstrated. Using commercial distributed feedback (DFB) laser diodes (LDs), a received power of -35 dBm at 10/sup -9/ BER is obtained, and the dispersion degradation over 100-km bidirectional transmission is negligible. With channel spacing of about 30 GHz, the differential power penalty is about 0.1 dB.<>