| 摘要 |
PURPOSE:To enable the stable oscillation of laser rays of different wavelengths with the same diffraction grating by a method wherein a laser is formed to have such a structure that the distance between the diffraction grating and an active layer is made to vary for every oscillating wavelength. CONSTITUTION:A buffer layer 2 and a lower clad layer 3 are formed on a substrate 1, and a first optical guide layer 5 and a second optical guide layer 6 are successively formed thereon in this order. At this point, a growth is made to stop once, and a wet etching is executed to remove a part of the second optical guide layer 6. Next, a dual light flux interference light exposure is performed to form diffraction gratings taking advantage of a secondary diffraction, where a diffraction grating 7 is formed primarily on the second optical guide layer 6 and a diffraction grating 8 is formed primarily on the first optical guide layer 5 and the pitch difference between the bottom and the top of the diffraction grating is made to be, for instance, 1000Angstrom . An upper clad layer 9 and a contact layer 10 are formed thereon, and the contact layer 10 and the clad layer 9 are partially processed to form an optical wave guide for the formation of a ridged type laser. |
