Repeated bidirectional transmission using two 4-port optical circulators and a bidirectional EDFA without isolators

Abstract

By using a newly designed bidirectional erbium-doped fiber amplifier, we demonstrated a 2 x 2.5 Gb/s repeated bidirectional transmission over a 100-km single-mode fiber. Two tunable optical bandpass filters were used to suppress the Rayleigh backscattering and amplified spontaneous emission in the bidirectional transmission system. The bit error rate performances were measured for both directions. A negligible power penalty of 0.2 dB for the 2 x 2.5 Gb/s transmission due to backreflections was observed when comparing the bidirectional transmission with single-channel, unidirectional transmission. (C) 1999 Academic Press.