| 摘要 |
PROBLEM TO BE SOLVED: To provide a phase shift type distribution feedback type semiconductor laser capable of suppressing the variation of laser efficiency due to the variety of cleavage position, and preventing the deviation of outgoing direction of light into up-and-down. SOLUTION: An active layer 2 is provided on an n-type InP substrate 1 while a diffraction grating 5 and a p-type InP clad layer 4 are provided on the active layer 2. The diffraction grating 5 is provided with at least one set of phase shift unit 6. Further, a reflection preventing film with a reflection factor of not more than 3% is provided on the end faces 7, 8 of the distribution feedback type semiconductor laser. In this case, the diffraction grating 5 is not provided on a region having a length of not less than 1μm and not more than 20μm in the direction of a waveguide path from the end faces 7, 8. COPYRIGHT: (C)2006,JPO&NCIPI
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