High output-power operation of 1.3 /spl mu/m gain-coupled DFB laser with narrow spectral-linewidth

High output-power and narrow spectral-linewidth operation of 1.3 /spl mu/m gain-coupled distributed feedback (DFB) lasers with InAsP buried absorptive grating are reported. In this report, we have investigated the effect of the thickness of separate-confinement-heterostructure (SCH) layer on the spectral linewidth. As a result, it was clarified that decreasing the thickness of SCH layer is effective to reduce the spectral linewidth. For the fabricated laser, a record high output-power of 230 mW and a minimum spectral-linewidth of 100 kHz was realized.