Room temperature lasing from InGaAs quantum dots

Alternating molecular beam epitaxy is used to form InGaAs quantum dots by utilising the two-dimensional to three-dimensional Stranski-Krastanow growth transition. The quantum dots are embedded in a separate confinement heterostructure to form laser diodes. Lasing is observed from excited states in the quantum dots from room temperature down to 80 K. Pronounced state-filling is observed in the quantum dot lasers at room temperature. As the temperature is decreased, the state-filling becomes less pronounced, which compensates for the bandgap increase and leads to lasers whose lasing wavelength is very weakly dependent on temperature