| 摘要 |
PROBLEM TO BE SOLVED: To reduce a noise and to provide a resistivity to the returning light by making the optical output stable even under the high output in a semiconductor laser device. SOLUTION: A ridge structure is formed by laminating an n-InGaP clad layer 12, an n-GaAs optical guide layer 13, an InGaAs distortion quantum well active layer 14, a p-GaAs first optical guide layer 15, a p-InGaAsP second optical guide layer 16, a p-InGaP clad layer 17. A p-GaAs contact layer 18 on an n-type GaAs substrate 11 are etched from the contact layer 18 down to the middle of the clad layer 17. A diffraction grating 5 comprising a plurality of periodical roughness in an axial direction of the stripes (the arrow Z-direction shown in Figure) is arranged in the interface between the first optical guide layer 15 and the second optical guide layer 16. |
