Optical spectroscopy of 1.3 μm (GaIn)(NAs)/GaAs lasers

The optical gain of MBE-grown and MOVPE-grown (GaIn)(NAs)/GaAs lasers and samples is investigated with different methods. A quantitative analysis of the experimental gain of commercial MBE-grown structures on the basis of a microscopic theory reveals that the gain is due to inhomogeneously broadened band-band transitions. In contrast, the authors´ analysis of an MOVPE-grown sample indicates that the optical gain is influenced by the locally varying environment of the nitrogen in the active region resulting in a strong shoulder in the gain spectra. The results demonstrate that the optical properties of (GaIn)(NAs)/GaAs strongly depend on the growth and preparation processes of the device under study.