A ridge waveguide DFB laser model including transverse carrier and optical effects

In this paper, a steady-state model for ridge waveguide DFB lasers is presented. The complex two-dimensional semivectorial optical mode in the transverse direction is solved using a finite difference scheme without introducing any approximations. The electron and hole diffusion in the lateral direction is also considered, Along the longitudinal direction, a novel “Superposition of Spectral Power Method” is used, based on the coupled mode formulation. This model enables one to examine the interaction between the optical and carrier profiles for different injection levels and arbitrary transverse index profiles. As such, it is useful for studying CW characteristics such as lasing wavelength and threshold current. Finally, the results from this model are compared with experimental data from a varying ridge width laser array fabricated from a 1.55 μm InGaAsP-InP compressively strained multiquantum-well loss-coupled DFB structure