Direct comparison of threshold and gain characteristics of 1300 nm GaInNAs lasers with GaNAs and GaAs barriers

Abstract

The threshold and gain characteristics of GaInNAs single quantum well (QW) lasers with GaNAs and GaAs barriers, both emitting at 1300 nm, have been compared. The threshold current density for the laser with GaAs barriers is twice as high, presumably because of a higher monomolecular recombination rate caused by the higher N concentration in the QW. A significant difference in the spectral gain characteristics was also observed. Calculations show that this is due to a modification of the confinement potential for the conduction band electrons when incorporating N in the barriers and reducing the N concentration in the QW. An additional inhomogeneous broadening also had to be included in the calculations to obtain quantitative agreement between measured and calculated gain spectra.