SEMICONDUCTOR OPTICAL ELEMENT AND SURFACE EMITTING SEMICONDUCTOR OPTICAL ELEMENT

摘要

PROBLEM TO BE SOLVED: To inhibit variation in optical coupling coefficients caused by variation in depths of a refractive-index-coupled diffraction gratings or periodic structure layers.SOLUTION: A semiconductor optical element 100 comprises a semiconductor substrate 1, a diffraction grating 2, a diffraction grating embedded layer 3, an active layer 4 and a clad layer 5. The diffraction grating 2 includes a plurality of grating pieces 2a which are arranged in a direction (Z direction) on the substrate 1, where laser beams are emitted. Each of the grating pieces 2a has a lower part 9 and an upper part 6 provided on the lower part 9. The lower parts 9 of the grating pieces 2a are connected to form one layer on a lower part of the diffraction grating 2. The upper part 6 has a first refractive coefficient nand the lower part 9 has a second refractive coefficient n(where n