Gain mechanism in an (AlGa)As double heterostructure laser

Presented here is substantial evidence of a specific quantum mechanical model for gain in a (AlGa)As double heterostructure laser with a pure active layer. Close quantitative agreement between predicted and measured values substantiates a new model that evolves directly from Stern's theory. A novel method employing picosecond optical probe pulses coupled axially to the semiconductor laser gain guide allows the first direct measurements of guide gain. The concept of optical impulse response is introduced. Current spreading and facet reflectivity are directly measured. The first self-consistent set of characteristic parameters for a specific laser are determined.