Characteristics of GaAs/AlGaAs quantum-wire distributed-feedback lasers with different gain modifications

GaAs/AlGaAs quantum-wire (QWR) gain-coupled distributed-feedback (GC-DFB) lasers were fabricated and characterized. Interestingly, as the shape of the active grating was varied, the lasing characteristics changed greatly; for example, one laser with sharp gratings lased at a threshold current of 13 mA while another one with dull gratings lased at 230 mA. This may be due to a change in the gain coupling coefficient with the shape of the QWR active grating. Little observation of the stopband and the wavelength consistency between the lasing and the photoluminescence peaks of the QWRs also provided evidence for lasing via GC-DFB effects in these devices.