Development of broad spectral bandwidth hybrid QW/QD structures from 1000-1400 nm

We describe the development of hybrid quantum well (QW)/quantum dot (QD) active elements to achieve broad spectral bandwidth spontaneous emission and gain. We have previously reported that the placement of the QW within the active element is a critical factor in obtaining broad spectral bandwidth emission. We now present new designs to further broaden the spontaneous emission from hybrid structures by increasing the number of QD layers and dot density, and by using QDs with wider state-separation. Introducing chirped QD layers reduced the modulation in the spontaneous emission spectra, and by utilising self-heating effects and state-filling, a spontaneous emission with 3dB line-width of 350nm is obtained.