Temperature dependence of the wavelength of quantum dot lasers

We have studied the properties of quantum dot lasers comprising a single layer of InGaAs dots set in a single GaAs quantum well 100 A wide in a waveguide core region of AlGaAs with cladding layers of AlGaAs. Measurements have been made of the optical absorption, optical mode loss and gain spectra as a function of temperature by single pass technique using a device with a segmented contact. We have made detailed studies of the gain spectra as a function of temperature which have enabled us to identify the origins of this temperature insensitivity and to infer information regarding the form of the broadened distribution of dot states.