Tensile strained MQW semiconductor optical amplifier

The relationship of the gain and saturation power to the strain or the number of wells is investigated for tensile strained MQW SOAs. It is proven that the saturation power decreases with increase of tensile strain, and that the gain increases with increase of the number of wells but the saturation power decreases. Next we fabricated two SOAs that are polarization-insensitive: one has 5 wells with -0.45% strain; and the other has 7 wells with -0.55% strain. The optical gains are 10.0 dB and 14.5 dB, the saturation power are 9.0 dBm and 6.5 dBm, respectively. The characteristics of signal power of non-degenerate four-wave mixing (NDFWM) are investigated using these SOAs. It is suggested that the SOA of larger gain generates larger signal power when the input power is small, while the SOA of larger saturation power generates larger signal power when the input power is around the SOA saturation power