| 摘要 |
PURPOSE:To implement a distribution feedback type semiconductor laser in a gain changing type and to obtain a single axial mode oscillation having good controllability, by providing a multilayer quantum well structure for a light guide, and changing the thickness of the multilayer quantum well structure at a period in accordance with an oscillating wavelength. CONSTITUTION:In a large gain part, a multilayer quantum well structure, in which six active layers 3 are provided and five barrier layers 4 are provided, is formed. In a small gain part, a multilayer quantum well structure, in which the three layers 3 and the three layers 4 are provided, is formed. In order to form the multilayer quantum well structures, the six active layers 3 and the five barrier layers 4 are alternately deposited. Thereafter, the respective layers are etched alternately by an etching method for only said layers. Grooves, in which the three active layers and the two barrier layers are removed, are formed. A guide layer 5 is deposited by a liquid phase growing method. Since the gain of the active region is approximately proportional to the thickness of the multilayer quantum well structure, the corrugation on the structure becomes the corrugation of the gain. Therefore, the corrugation of the change in gain can be implemented. The laser, which is suitable for a power source for long-range, large-capacity optical communications is obtained. |
