EDFA gain stabilization with fast transient behavior by use of a semiconductor optical amplifier

Abstract

We propose a solution to improve gain-clamped EDFA stabilization time by inserting in the conventional laser loop configuration an extra SOA. Experimental results demonstrate stabilization time as short as 0.2µs in a purposely-considered critical situation.

Gain transient control for wavelength division multiplexed access networks using semiconductor optical amplifiers

“…We propose that the benefits of an SOA integrated within a WDM receiver at the metro node could be extended beyond pre-detection amplification to include signal restoration in the presence of transients. In the past a number of general transient control methods have already been proposed, including EDFA gain clamping using an optical feedback loop [6,7], electrical feedforward/feedback control of the pump power [8,9], clamping the EDFA with a holding beam to limit the variance in the total optical input power [10], and the use of saturated or near-saturated semiconductor optical amplifiers [11][12][13][14][15]. To the best of our knowledge however, we are the first to present 10 Gb/s fiber transmission bit error rate (BER) measurement results illustrating transient control using a nearsaturated SOA.…”