Effects of rapid thermal annealing (RTA) on emission properties of InAsSbN quantum well laser diodes grown on InP substrates were studied. It was found that a marked enhancement of electroluminescence (EL) intensity about one order of magnitude and a blue-shift of the EL peak energy was observed at low temperature upon RTA. On the other hand, no blue-shift of the EL peak energy was observed near at room temperature. The observed EL peak blue-shift at low temperature can be explained by decrease in localized levels formed by nitrogen introduction in the InAsSbN quantum wells. Laser operation was obtained for both diodes with and without RTA. It was found that threshold current density J(th) of the InAsSbN laser diode with RTA reduces compared to that without RTA. The lasing wavelength of the diode before RTA is 2.31 mu m at 190 K, while that of the diode after RTA is 2.28 mu m at 210 K. The T-o values are 60 K for both diodes. (c) 2007 Elsevier B.V. All rights reserved.