Broadband superluminescent diodes incorporating multiple layers of InAs quantum dots (QDs), where the dots height was deliberately varied from one layer to another have been grown and characterized. We used the indium-flush process to accurately control the emission energy of each layer of dots, enabling us to reliability and predictably engineer the bandwidth of the overlapped layers. Photoluminescence spectrum of four combined layers of QDs with full-width at half-maximum of 125 nm at peak wavelength energy of 1.06 mu m was obtained. A 3 dB bandwidth emission spectrum of 80 nm and output power of 1 mW was obtained under CW operation mode at room temperature. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.