Abstract
An ensemble Monte Carlo simulation method has been used to model the carrier dynamics of optically pumped intersubband lasers. GaAs/AlGaAs asymmetric (single step) and triple quantum well structures are studied: both are 4-subband systems designed for intersubband pumping by a 10.6 μm CO2 laser, and for far-infrared emission at 11.7 THz (25.6 μm). The simulations predict population inversion at 77 K for the asymmetric quantum well, but not at 300 K, whence intersubband electron-electron interactions cause significant re-distribution of electron kinetic energies in the 4th subband. However, simulations of the triple quantum well structure show strong inversion at 77 K, and marginal inversion at 300 K. The improved performance of the triple quantum structure in this case is attributed to stronger 3rd-2nd subband scattering (which depopulates the lower of the two laser levels) due to an anticrossing of eigenstates, and to reduced energy re-distribution effects.
| Original language | English |
|---|---|
| Pages (from-to) | 48-51 |
| Number of pages | 4 |
| Journal | Physica E: Low-Dimensional Systems and Nanostructures |
| Volume | 7 |
| Issue number | 1-2 |
| Early online date | 20 Mar 2000 |
| DOIs | |
| Publication status | Published - 1 Apr 2000 |
| Externally published | Yes |
| Event | The 5th International Conference on Intersubband Transitions in Quantum Wells - Bad Ischl, Austria Duration: 7 Sep 1999 → 11 Sep 1999 Conference number: 5 |
