ABSTRACT
For future metropolitan area networks the demand for inexpensive ultrafast amplifiers is probably larger than that of lasers. Semiconductor optical amplifiers (SOAs) are expected to play a decisive role here. Quite surprisingly QD SOAs based on GaAs show similar promise to outperform InGaAsP bulk and QW SOAs as in the case of lasers since QD SOAs show gain recovery times of 140 fs, 4-7 times faster than classical ones [16, 17]. Additional advantages of QD SOAs are reduced chirp [9], larger saturated gain [18], no cross gain modulation [19], etc.
