The threshold current density (J(th)) of blue-green CdZnSe/ZnSSe strai
ned quantum well lasers is analysed using the laser theory established
for III-V semiconductor lasers. Very good agreement between theory an
d the reported experimental J(th) values is obtained over a wide tempe
rature range from 77 to 273 K. The optimal Cd composition of a CdZnSe
single quantum well active layer for obtaining a low J(th) value at ro
om temperature is in the range 0.25-0.30.