LINEWIDTH ENHANCEMENT FACTOR AND HIGH-TEMPERATURE PERFORMANCE OF 1.48-MU-M STRAINED INGAAS-INGAASP MULTIQUANTUM WELL LASERS

The linewidth enhancement factor alpha in strained InGaAs-InGaAsP multiquantum well (MQW) lasers emitting near 1.48-mu-m has been experimentally determined. The measured alpha at the lasing wave-length is found to be 2 compared to a value of 5.5 and 3.5 typically observed in InGaAsP-InP regular double heterostructure (DH) lasers and MQW lasers, respectively. The small alpha shows that single wave-length strained MQW lasers will have smaller chirp width under modulation and also smaller CW linewidth. The carrier lifetime at threshold in these strained MQW lasers does not decrease as rapidly with increasing temperature as is observed for regular InGaAsP-InP DH lasers. This indicates a smaller nonradiative carrier loss due to Auger recombination in strained quantum wells. The features such as low alpha and low carrier loss at high temperature result in performance improvement of lasers that are advantageous for lightwave system application.