Erbium-doped waveguide amplifier for reconfigurable WDM metro networks

Transient dynamic due to signal power fluctuations is the main impairment in reconfigurable transparent wavelength-division-multiplexing metro networks design. In this letter, we demonstrate an optical-gain-clamped erbium-doped waveguide amplifier using fiber Bragg grating filters. We show both theoretically and experimentally that it is virtually insensitive to signal transient and that it reduces overshoot by 10 dB compared to standard erbium-doped fiber amplifiers. The device modeling shows that short highly doped optical amplifiers are insensitive to input signal level transient and will outperform longer fiber-based identical operating condition amplifiers. In fact, erbium-doped waveguide optical amplifiers do not exhibit any transient dynamic effect that can be detrimental after accumulation along the amplifier chain. In addition, waveguide amplifiers will require less extra pump to stabilize optical clamping, thus reducing clamping implementation cost.