Degradation behavior of the active region and passive region in buried heterostructure (BH) distributed Bragg reflector (DBR) lasers

Changes in the threshold current and wavelength tuning characteristics due to the degradation of the active region and passive region in buried heterostructure (BH) distributed Bragg reflector (DBR) lasers are experimentally investigated. These changes are caused by the decrease in recombination carrier lifetime due to degradation. It is ashown that the decrease in the carrier lifetime is mainly accelerated as a result of increased carrier density. This suggests that the degradation of the active region depends more strongly on the threshold current density than on the operating current. On the other hand, the degradation of the passive region is related to the injected current density, which affects the stability of the wavelength tunability of DBR lasers. 1999 Elsevier Science Ltd. All rights reserved.