| 摘要 |
PURPOSE:To control the length of a diffraction grating region, to obtain a predetermined coupling factor with good controllability and to stabilize the oscillation of single mode by dividing the interior of a laser resonator by a triangular grating to provide the grating region. CONSTITUTION:Diffraction grating regions 10 divided into a plurality in a direction for forming a laser resonator are provided on a photoconductive layer 12 adjacent to an active layer 13. A diffraction grating is formed of a triangular shape formed of a general surface (111) formed on compound semiconductor of a surface orientation (100). When the value of the coupling factor of the grating is set in a range of 1 to 2, a distributed feedback type semiconductor element which is oscillated in a single longitudinal mode is obtained. |
