Abstract

Modulation damping of single-frequency distributed-feedback (DFB) lasers relates direectly to the performance of 1.55-pm systems using standard nondispersion-shifted fiber.¹ We have found previously that lasers with longitudinal nonuniformity exhibit narrow modulated spectra and a low dispersion penalty at 1.55 pm? We report here that the good system performance originates from the high modulation damping associated with lasers that have a nonuniform carrier and optical longitudinal nonuniformity. Forcomparison, the behaviors of DFB lasers with longitudinal nonuniformity (laser B) and without longitudinal nonuniformity (laser AO are described in two experimental aspects: (1) optical pulse response, and (2) transient wavelength chirping. A nearly dispersion-penalty-free transmission over 80 km at 2.5 Gb/s is also demonstrated with laser B.

© 1991 Optical Society of America