In0.5Ga0.5As quantum dot lasers grown on (100) and (311)B GaAs substrates

A comprehensive study is presented of the properties of ridge lasers incorp orating In0.5Ca0.5As self-assembled quantum dots grown on (3 1 1)B and (1 0 0) oriented GaAs substrates. Various laser designs are used to optimize th e threshold current density J(th) and the characteristic temperature T-0. A lso, the effect of a thermal annealing of the samples is investigated as a mean of tuning the laser energy emission. Finally, we show an unusual tempe rature dependence of the laser emission: increasing temperature from 10 to 290 K produces a narrowing of the dot laser mode distribution. (C) 1999 Els evier Science B.V. All rights reserved.