Microscopic theory of optical gain in small semiconductor quantum dots

A microscopic theory is used to analyze optical gain in small semiconductor quantum dots. Based on a numerical matrix diagonalization method and subsequent solution of the optical Bloch equations, it is found that the quantum-dot gain is dominated by the stimulated transitions between biexciton and exciton states. The calculation shows that Coulomb interaction and valence-band mixing effects significantly influence the spectral and dynamic gain properties in strongly confined quantum dots. © 1996 The American Physical Society.