Structure of the quantum well for a broad-band semiconductor optical amplifier

For the Bat-gain characteristics of semiconductor optical amplifiers in the broad range, we used a non-uniform quantum well structure. The flat gain i n the broad band is made possible by optimizing the variation of the well's thickness. We also showed the gain characteristics for different arrangeme nts of the quantum wells from the p or the n side. As expected theoreticall y, the gain of the broad bandwidth was characterized by using a photolumine scence measurement.