1.55- mu m narrow-linewidth and high-power distributed feedback lasers for coherent transmission systems

Stable operation of 1.55- mu m distributed feedback lasers with a narrow linewidth and high power is demonstrated for coherent transmission systems. Narrow linewidth and high power were realized by improving the geometrical uniformity of the active region and thinning the active layer by using MOVPE and a dry-etching technique. A narrow linewidth of 1 MHz was achieved at a high power of 20 mW for a distributed feedback laser with a thin active layer of 0.07 mu m and a long cavity of 1.2 mm.<
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