OPTICAL GAIN AND LASING IN SELF-ASSEMBLED INP GAINP QUANTUM DOTS/

Optical gain measurements have been performed on self-assembled InP qu antum dots embedded in GaInP. The dots are formed during the growth of InP on GaInP by molecular beam epitaxy due to the strong lattice mism atch and are overgrown with GaInP afterwards. The optical gain spectra show two peaks which could be clearly identified by their polarizatio n properties as being due to the quantum dots and the wetting layer, r espectively. As expected from the results of the gain measurements, op tical pumping of cleaved samples at room temperature leads to lasing o f either the quantum dots or the wetting layer, depending on the exper imental conditions. (C) 1996 American Institute of Physics.