Influence of pump direction in all-optical gain-clamped erbium doped fiber amplifier

We demonstrate the influence of pump direction in the all-optical gain-clamped erbium doped fiber amplifier configuration using optical circulators in the feedback loop. The circulator disposition imposes the clamping laser to counterpropagate with the probe signal. We showed a better performance when the pump laser copropagates with the probe signal for operation conditions. We also compare the performance of this configuration with the one that uses directional couplers in the feedback loop.