| abstract |
A quantum dot active region in which a quantum dot layer is formed using a self-assembled growth technique is disclosed. In one embodiment, growth parameters that control dot density and dot size distribution are selected to achieve desired optical gain spectral characteristics. In one embodiment, a sequence of dot size distributions and optical transition energies corresponding to the quantum confinement of the dots is selected to facilitate formation of a continuous optical gain spectrum over an extended wavelength range. In another embodiment, the optical gain is selected to increase the saturated ground state gain for wavelengths above 1260 nanometers. In other embodiments, quantum dots are used as the active area of various laser devices, including tunable lasers and monolithic multi-wavelength laser arrays. |