| 摘要 |
PURPOSE:To enable a plurality of active layers to be disposed on a group of waveguide layers disposed on the same optical axis so that the active layers are in close proximity with each other, by forming diffraction lattices on waveguide layers, the lattices respectively having periods corresponding to the respective oscillation wavelengths of a plurality of active layers, and separating the diffraction lattices so that no reflection occurs between the waveguide layers. CONSTITUTION:A multi-wavelength semiconductor laser having a combination of various kinds of wavelength can be formed by appropriately selecting a composition for each of the active layers 14a, 14b of first and second semiconductor lasers and a period for each of the diffraction lattices 23a, 23b. Etched surfaces 25a, 25b are formed by chemical etching or the like in such a manner that they slant with respect to the corresponding end faces of waveguide layers 13 so as not to constitute reflecting surfaces. The waveguide layers 13 are not always required to have the same energy band gap and may have different energy band gaps corresponding to the active layers 14a, 14b. It is, however, necessary for the waveguide layers 13 to have an energy band gap which is larger than those of the active layers 14a, 14b. The diffraction lattices 23a, 23b are separated from each other so that no reflection occurs between the waveguide layers 13. |
