Long-wavelength emission from self-organized InAs quantum dots on GaAs substrates

We report on several approaches for extending the optical emission range for GaAs based heterostructures by using the self-organized InAs quantum dots. Placing the InAs quantum dots into InCaAs/GaAs quantum well led to achieving the 1.3 mu m spontaneous emission and 1.26 mu m lasing with extremely low threshold current density of 70 A/cm(2) at room temperature. Low temperature deposition of InAs quantum dots resulted in the formation of agglomerates of quantum dots which were the origin of the 1.75 mu m emission at room temperature. FIR emission simultaneous to 0.94 mu m lasing has been observed in InGaAs quantum dot lasers due to intersubband carrier transitions in quantum dots. (C) 1999 Elsevier Science Ltd. All rights reserved.