Single-Fiber Bi-Directional Burst-Mode EDFA for TWDM-PON

In this paper, we propose a single-fiber bi-directional burst-mode erbium-doped fiber amplifier (EDFA) to simultaneously improve upstream and downstream loss budget in time and wavelength division multiplexed–passive optical network (TWDM-PON). Instead of additional light sources for upstream gain clamping, the downstream signal acting as saturation signal effectively suppresses the upstream burst surge, which widens the input dynamic range of upstream burst signal. For potential reflections caused by the absence of optical isolators, experimental results have demonstrated the degradation of receiver sensitivity at bit-error rate of $1 \times 10^{-3}$ is negligible with a reflection power up to −14 dBm, which proves the promising applications in PONs of the proposed single-fiber bi-directional burst-mode EDFA.