THEORETICAL OPTIMIZATION OF V-SHAPED GAINASP QUANTUM-WELL LASERS GROWN ON INP SUBSTRATES

Compressively strained GaInAsP quantum wells (QW's), with a square pot ential profile and grown on InP substrates, have demonstrated their hi gh potential for the improvement of 1.55-mu m lasers, Recently, we hav e proposed another approach which consists of creating a linear variat ion of the bandgap inside the well, by means of a linear variation in the As concentration, Calculations show that, in such a V-shaped struc ture: 1) the effective density of states related to the heavy hole ban ds is reduced compared to that of a large abrupt-shaped QW and 2) the overlap between the electron and the hole wavefunctions is expected to be greater than in a narrow abrupt-shaped QW. The consequences of the se effects are described.