The Effect of Electron Escape Rate on the Nonlinear Dynamics of Quantum Dot Lasers under Optical Feedback

Abstract

When theoretically investigating the nonlinear dynamics of quantum dot lasers (QDLs), the parameter value of the electron escape rate (Ce) is sometimes approximated to zero to simplify the calculation. However, the value of Ce is dependent on the energy interval between the ground state (GS) and the excited state (ES) in the conduction band and is affected by the operation temperature. As a result, such simplified approximation treatments may lead to inaccurate results. In this study, after considering the effect of Ce, we investigate the nonlinear dynamics of QDLs with and without optical feedback based on the asymmetric electron-hole carrier rate equation model. The simulation results show that without optical feedback, the lasing conditions for ES and GS in free-running QDLs are dependent on the value of Ce. A larger Ce is more helpful for the ES emission, and the GS emission will stop lasing if Ce is large enough. Through analyzing the dynamical characteristics of GS and ES in QDLs with optical feedback under different Ce values, it can be found that the dynamical characteristics are strongly correlative with Ce.