VERTICAL MICROCAVITY LASERS WITH INGAAS GAAS QUANTUM DOTS FORMED BY SPINODAL PHASE-SEPARATION/

We report the growth, characterization and lasing of vertical microcav ity lasers with an active layer of self-organized. InGaAs/GaAs quantum dots. The quantum dots are formed by spinodal phase separation in low -In-content (x = 0.03) In-x Ga1-xAs epilayers deposited with decreasin g growth temperature in a hot-wall metalorganic chemical vapor deposit ion reactor. Optical transitions involving ground and excited states o f the quantum dots were investigated using photoluminescence at modera tely high excitation densities. Lasing oscillation was observed at 77 K by optical pumping. The coupling parameter beta of the spontaneous e mission into the lasing mode was estimated to be similar to 8 x 10(-3) .