Gain and phase dynamics in strained quantum well semiconductor optical amplifiers

Abstract

Gain and phase dynamic characteristics in the compressive, unstrained and tensile strained InGaAs-InGaAsP quantum well (QW) semiconductor optical amplifiers (SOAs) are theoretically investigated via a detailed model. Based on the calculation of energy band structure, the effects of compressive and tensile strain on the differential gain and the derivative of refractive index change are investigated. It is demonstrated that the compressive strained QW SOA shows the fastest gain recovery rate and the largest phase change. That is because the SOA has the characteristics of the largest differential gain and the smallest derivative of refractive index change. In addition, the ultrafast recovery process due to the carrier heating effect can be enhanced significantly in the tensile strained QW SOA.