High-energy (Visible-red) stimulated emission in GaAs

Abstract

The high-energy (visible-red) photpumped laser operation (6345 Å at 77 K, 6785 Å at 300 K) of AlxGa1−xAs-AlAs-GaAs quantum-well heterostructures (QWH) grown by metalorganic chemical vapor deposition (MO-CVD) is described. The QWH active regions are alloy-free and consist of GaAs quantum wells and AlAs barrier layers. The effect of the AlAs barrier-layer thickness on the energy banding of the confined-carrier states and transitions is demonstrated. The laser operation of the coupled GaAs quantum wells is observed as high as 400–445 meV above the bulk-GaAs band edge, which agrees with the calculated locations (Lz∼30 Å) of the lowest (n = 1) electron, heavy-hole, and light-hole confined-particle states or energy bands.