Vertical Microcavity Lasers with InGaAs/GaAs Quantum Dots Formed by Spinodal Phase Separation

We report the growth, characterization and lasing of vertical microcavity 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 Ga_{1- x} As epilayers deposited with decreasing growth temperature in a hot-wall metalorganic chemical vapor deposition reactor. Optical transitions involving ground and excited states of the quantum dots were investigated using photoluminescence at moderately high excitation densities. Lasing oscillation was observed at 77 K by optical pumping. The coupling parameter β of the spontaneous emission into the lasing mode was estimated to be ∼8×10^-3.