Design and performance optimization of optically-pumped mid-infrared intersubband semiconductor lasers

We show that self-consistent simulations of asymmetric coupled double-quantum wells (ACQW) can be used efficiently to increase significantly the optical performances of optically-pumped mid-infrared intersubband semiconductor lasers by increasing the electron concentration in the quantum well. Our calculations, which account for the screening effect and degenerate statistics, show optical gain in excess of 100/cm for pumping intensity of 39 kW/cm/sup 2/ can be achieved. Owing to hot electron effects, the stimulated gain at 77 K is insensitive to the phonon resonance for pumping intensities larger than 400 kW/cm/sup 2/.