Variation of spontaneous emission with current in GaAs homostructure and double-heterostructure injection lasers

Partial saturation and change of the slope of the spontaneous emission are observed in CW homostructure GaAs lasers and pulsed homostructure and DH GaAs lasers at the onset of the laser modes. An important new effect that we have observed is a reduction of the spontaneous emission above threshold for homostructure lasers. The results are discussed in comparison with the previously published work and a possible explanation for the difference of behavior between homostructure and DH lasers is proposed.