Laser properties and carrier collection in ultrathin quantum-well heterostructures

Stimulated emission from a series of AlGaAs-GaAs single-quantum-well heterostructures is demonstrated for well-widths as thin as 8.5 AA at 22 K. These undoped samples, grown by molecular beam epitaxy, are the thinnest single quantum wells reported to support stimulated emission. Laser thresholds are quite low despite the fact that the single well is undoped and of dimensions that were previously thought to be too small to collect excess carriers effectively (L/sub z/<>