| 摘要 |
PROBLEM TO BE SOLVED: To provide semiconductor laser for generating a light signal with a small wavelength chirp by a direct modulation method. SOLUTION: Each of a forward-distributed feedback active region 101, a center-distributed feedback active region 102, and a backward-distributed feedback active region 103 is equipped with a diffraction grating 5 buried in a p-type InP clad layer 4 in the proximity of an upper surface 3a of an optical waveguide layer 3. The diffraction grating 5 in the center-distributed feedback active region 102 has a phase shift 6 formed. The size of the phase shift 6 is 3λ/8 for example whereλrefers to a Bragg wavelength. COPYRIGHT: (C)2008,JPO&INPIT
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