Short-wavelength current tuning of InAsSb/InAsSbP heterostructure lasers caused by an injection nonuniformity

A reduction in the emission wavelength in the preferred mode of InAsSbP/InA sSb/InAsSbP heterostructure lasers by 50 Angstrom is observed when the curr ent is raised from 1.8 to 5 times the threshold with dc and pulsed power. A comparison of the spectral and spatial distributions of the output as func tions of current shows that this short-wavelength tuning is caused by a cha nge in the distribution of the nonequilibrium charge carrier concentration over the strip width as the current is varied. This effect is modeled mathe matically, taking into account the increase in the injection density and th e drop in the output intensity from the middle to the sides of the waveguid e. The results of the model calculation are in good agreement with experime nt. (C) 1999 American Institute of Physics. [S1063- 7826(99)01609-9].