ESTIMATION OF THE RELIABILITY OF 0.98 MU-M INGAAS/GAAS STRAINED QUANTUM-WELL LASERS

A reliability study has been made on 0.98-mu-m InGaAs/GaAs strained quantum well ridge waveguide lasers for pumping erbium-doped fiber optical amplifiers (EDFAs). Analysis of a constant power long-term aging test over 10(4) h shows that the degradation rate is proportional to the square root of the aging time irrespective of operating output power. A simple relationship is found between degradation rate and both operation current density and optical density. The change in light-current characteristics and emission wavelength during constant current aging are also investigated. It is found that emission wavelength exhibits a blue shift for an identical operation current accompanied by laser degradation due to an increased threshold carrier density. In constant-power mode aging, on the other hand, the shift is found to be rather complicated because of an additional factor of an increase in junction temperature causing a red shift. The influence of the wavelength shift on amplification characteristics in EDFAs is also discussed.