Optical gain and loss in 3 μm diode "W" quantum-well lasers

Gain in broad-area midinfrared diode "W" lasers (lambda=3-3.1 mum) has been measured using lateral mode spatial filtering combined with the Hakki-Paoli approach. The internal optical loss of approximate to19 cm(-1) determined from the gain spectra was the same for devices with either ten or five period active regions and nearly constant in the temperature range between 80 and 160 K. Analysis of the differential gain and spontaneous emission spectra shows that the main contribution to the temperature dependence of the threshold current is Auger recombination, which dominates within almost the entire temperature range studied (80-160 K). (C) 2002 American Institute of Physics.