LASER TRANSITION TO BAND EDGE OR TO IMPURITY STATES IN GaAs:Ge

Data are presented showing that p-type GaAs:Ge can be lased on band-to-band, conduction band-to-acceptor impurity, or simultaneously on both transitions. Recombination transitions to the Ge acceptor impurity are well separated in energy from those to the neighboring band edge, and in spectral width (spontaneous recombination) are in reasonable agreement with previous theory.