Emission dynamics and optical gain of 1.3-μm (GaIn)(NAs)/GaAs lasers

The ultrafast emission dynamics of a 1.3-μm (GaIn)(NAs)/GaAs vertical-cavity surface-emitting laser is studied by femtosecond luminescence upconversion. We obtain a minimum peak delay of 15.5 ps and a minimum pulse width of 10.5 ps. Laser operation with picosecond emission dynamics is demonstrated over a temperature range from 30 to 388 K. The bandgap shift with temperature of (GaIn)(NAs)/GaAs is determined to be about -2.9 · 10-4 eV/K, which is smaller than for GaAs. Our measurements of the optical gain provide gain spectra similar to those of commercial (GaIn)(PAs)/InP - structures at moderate densities but broaden considerably for elevated carrier densities due to the stronger carrier confinement. We compare our experimental results with gain spectra calculated from a microscopic model and confirm the predictive capability of the model. The theoretical gain spectra are used as the input for a calculation of the temperature dependence of the (GaIn)(NAs)/GaAs surface-emitter emission which results in very good agreement with experiment.