THEORETICAL INVESTIGATION OF GAIN AND LINEWIDTH ENHANCEMENT FACTOR FOR 1.55-MU-M TENSILE-STRAINED QUANTUM-WELL LASERS

The performance of quantum-well laser diodes with tensile strained wel ls was theoretically calculated. Using 4 x 4 Luttinger-Kohn Hamiltonia n, valence band dispersion was calculated and used for the calculation of material gain. Linewidth enhancement factor was obtained by calcul ating the change of refractive index due to interband transition and f ree carrier plasma motion. The tensile well shows smaller material and differential gain compared to the compressive strained one. But small er linewidth enhancement factor is obtained due to the absence of free carrier plasma effect. Linewidth enhancement factor is further reduce d by p-type modulation doping in the barrier.