Abstract

Longitudinal spatial hole burning (LSHB) is known to cause a deterioration in the single-mode stability of distributed-feedback (DFB) lasers at high output powers,¹ to produce a nonlinearity in the laser characteristics, and to cause adiabatic chirp, all highly detrimental to the achievement of narrow-linewidth operation or distortionless AM/FM modulation. Reduction of LSHB has been reported by using gratings with a longitudinally carving phase, which results in narrow-linewidth operation.² This paper describes how a longitudinal tailoring of the coupling-coefficient magnitude is necessary for completely eliminating LSHB. A practical implementation will be introduced and analyzed.

© 1994 Optical Society of America