Efficient Erbium-doped waveguide amplifier insensitive to power fluctuations.

We describe an efficient erbium-doped waveguide amplifier insensitive to output power variation by means of optical gain clamping. Output power suitable for metro applications and gain flatness over full C-band are demonstrated. We also show that this technology is suitable for transparent WDM ring network. In fact the possible recirculation of amplified spontaneous emission noise or laser power leaking from mirrors will not impact the device performance making robust to transients for next generation reconfigurable WDM ring networks.