Title: Monte Carlo Simulation of Electron Dynamics in GaAs-based Mid-infrared Quantum Cascade Lasers

Speaker: Xujiao (Suzey) Gao University of Wisconsin - Madison

Date/Time:  Monday, March 1, 2010, 9:00 am       

Location: CSRI Building/Room 90 (Sandia NM)

Brief Abstract: This seminar will present the modeling of electron transport in GaAs-based quantum cascade lasers (QCLs) using the ensemble Monte Carlo approach. QCLs are electrically-pumped unipolar mid- to far-infrared coherent light sources based on intersubband transition and quantum tunneling. Several issues including carrier leakage and electron heating limit the performance of GaAs-based mid-infrared (mid-IR) QCLs. To address these issues, a detailed Monte Carlo simulator including both Gamma- and X-valley transport was developed and had been applied to investigate the X-valley leakage in two well-known GaAs/AlGaAs mid-IR QCLs. The simulator is able to quantify both the Gamma-continuum and X-valley leakage currents, and characterize the electron heating in a given QCL structure. The simulator was also employed to optimize a deep-active-well GaAs QCL design which allows for lasing at a shorter wavelength below the known wavelength limit with no penalty in device performance. Furthermore, phonon spatial confinement was fully incorporated in the multivalley simulator and its effects on the transport properties of GaAs QCLs were investigated in detail.

CSRI POC: Gary Hennigan, (505) 845-7558