ANALYSIS OF OSCILLATION CHARACTERISTICS OF SEPARATED-ELECTRODE DFB LASER-DIODES

We analyze the oscillation characteristics of separated-electrode DFB lasers by a numerical approach. In the calculation, we use the coupled-mode equations including the carrier-density nonuniformity along the laser axis, which is introduced by the spatial hole burning and/or the nonuniform current injection. When the center section of a DFB laser, with equally separated three electrodes, is more strongly pumped than the side sections, high performance is achieved: the mode stability is maintained in the highpower state, resulting in a narrow linewidth. This is because the spatial hole burning is compensated for by the larger current injection into the center region. The wide tunable range is also obtained under this bias condition.