| 摘要 |
PURPOSE:To obtain a multiple-wavelength light source which can take out more than one laser beams from an identical region of a substrate by a simple structure and with good directivity by a method wherein the following are formed: more than one laser arranged on an identical substrate in different directions: a diffraction grating body formed in the identical region of the substrate by mutually piling up diffraction gratings corresponding to the lasers. CONSTITUTION:The following are formed: more than one distributed Bragg reflection laser A, B or distributed feedback laser, which is arranged on an identical substrate 1 in different directions; a diffraction grating body 3 which is formed in the identical region of said substrate 1 by mutually piling up diffraction gratings corresponding to said lasers A, B. For example, a beam of light radiated at a multiple-quantum-well layer 6 by injection of an electric current is multiple-reflected at a cleavage plane and at a diffraction grating, and is radiated as a laser beam from the cleavage plane and the diffraction grating. In order to take out one part of the laser beam from the diffraction grating in the vertical direction, the cycle of the diffraction grating is made identical to the wavelength of the laser. That is to say, the laser beam is fed back by a secondary diffraction effect, and, at the same time, one part of the laser beam is taken out by a primary diffraction effect in the vertical direction. |
