Abstract
We consider theoretically the formation and stability of quasi-one-dimensional many-body excitons in GaAs quantum wire structures under external photoexcitation conditions by solving the dynamically screened Bethe-Salpeter equation for realistic Coulomb interaction. In agreement with several recent experimental findings the calculated excitonic peak shows weak carrier-density dependence up to (and even above) the Mott transition density, n c ∼ 3 × 10 5 cm -1 . Above n c we find considerable optical gain demonstrating compellingly the possibility of a one-dimensional quantum wire laser operation.