Characteristics of InGaAsN/GaAsN quantum well lasers emitting in the 1.4-mm regime

To improve the performance of metalorganic chemical vapor deposition (MOCVD)-grown long wavelength InGaAsN quantum well (QW) diode lasers emitting beyond 1.3 mm, a detailed examination of the growth parameters was performed, including DMHy/V ratio, QW growth temperature, choice of barrier material and thermal annealing temperature. This study reveals that a growth temperature in the 530–540 1C range is preferred in order to improve nitrogen incorporation and prevent degradation of the material luminescence. Increasing the DMHy/V ratio is found to be the preferred method to achieve wavelength extension. Utilization of GaAsN barrier layers, instead of GaAs barriers, suppresses the spectral blue-shift of the quantum well luminescence after thermal annealing treatment. Under optimized growth conditions, InGaAsN diode lasers emitting at 1.378mm are realized with a threshold current density of 661A/cm and external differential quantum efficiency of 34%. Lasing wavelengths as long as 1.41 mm with a threshold current density of 1.93 kA/cm are also demonstrated, representing the longest wavelength InGaAsN QW lasers realized by MOCVD. r 2004 Elsevier B.V. All rights reserved. PACS: 42.55.P, 81.40.E, 78.66, 81.15.G, 61.10.N, 78.55.E