Ultra-broad spontaneous emission and modal gain spectrum from a hybrid quantum well/quantum dot laser structure

We propose and demonstrate a hybrid quantum well/quantum dot structure to enhance the gain and spontaneous emission bandwidth of a quantum dot active region. A single quantum well is introduced into a multi-layer stack of quantum dots, spectrally positioned to cancel the losses due to the second excited state of the dots. As a result, the modal gain at room temperature is extended to 300 nm, covering the wavelength range of 1100-1400 nm, and spontaneous emission has a 250 nm, 3 dB linewidth from 1080-1335 nm, of interest to short-haul telecom and optical coherence tomography applications.