The mechanism investigation of ultrafast all-optical switch based on electron spin polarization relaxation at 1.55 μm

摘要

Exciton saturation and optical nonlinearities caused by phase-space filling(PSF) in InGaAs(P) MQWs are investigated. In-well carrier population under pump beam is calculated as a function of time. Changes in absorption of the two circularly polarized component of the linear polarized test beam resulting from PSF are calculated by the semiconductor nonlinear absorption formula, respectively. The refractive indices of the two circularly polarized component are obtained from the K-K relations. Transient rotation angle of the major axis of the probe polarization is then deduced.