AGING-INDUCED WAVELENGTH SHIFTS IN 1.5-MU-M DFB LASERS

We report measured wavelength shifts of over one hundred 1.5-mum DFB l asers aged under three different conditions for a period corresponding to the system's lifetime (approximately 25 years). The results show t hat the lasers aged at lower temperature (thus higher optical power) h ave wider spread of wavelength shifts than the lasers aged at higher t emperature. No correlation was observed between the wavelength shifts and the aging rates or the aging-induced changes in the threshold curr ents. The aging-induced wavelength shifts were relatively small (+/-1 angstrom) for most lasers. However, about 10% of the lasers exhibit la rger wavelength shifts of up to about +/-4 angstrom.