The effects of longitudinal gain distributions on the static and the dynamic properties in a λ/4 phase-shifted DFB laser

The static and dynamic behaviors of the index-coupled DFB lasers are analyzed. In previous models, spatially dependent values were used for the refractive index distribution, but an averaged value was used for the gain distribution. The key feature of our model is that the “refractive index” and “gain” distributions are spatially dependent. The results of our model show a better agreement with an accurate model such as experimental data compared to those of the previous models. It was known that in the index-coupled DFB-lasers the gain profile as well as the refractive index profile plays an important role in determining the lasing characteristics, such as mode instability, chirping, linearity in the GRIN curve, and output power