Assessing aging in tunable electro-absorption modulated, distributed Bragg reflector lasers
01 January 2000
Summary form only given. Tunable optical sources used in dense wavelength division multiplexed (DWDM) systems, such as distributed Bragg reflector (DBR) lasers, are highly susceptible to aging-induced wavelength drift. Without the stabilizing influence of gain clamping in the tuning section, the tendency for a tunable source to drift is greater than that of a fixed wavelength source, such as a distributed feedback or electroabsorption modulated laser. Aging of tuning sections can cause a free-running tunable source to wander out of an allotted channel band or, in a severe case, to mode hop. Wavelength drift in a tunable source is mitigated by closed loop feedback, but with time, aging still distorts the multi-dimensional channel map of optimized operating conditions. Assessing the potential for a tunable source to age is essential to ensuring device and system reliability. Using a novel technique, we assess aging in an electro-absorption modulated, distributed Bragg reflector (EADBR) laser using change of Bragg wavelength as a measure of increase of non-radiative recombination