Patent ID: 7426228

Claim:
A surface emitting type optical semiconductor device comprising: a substrate; a first reflecting mirror layer provided on the substrate and having a first semiconductor multilayer film; a semiconductor active layer provided above the first reflecting mirror layer and having a light emitting region; a second reflecting mirror layer provided above the semiconductor active layer and having a second semiconductor multilayer film, the first and second reflecting mirror layers forming an optical cavity in a direction perpendicular to the substrate; a current confinement region provided in the second reflecting mirror layer so as to be surrounded by an impurity region having impurities, the current confinement region having current confining paths; a semiconductor current diffusion layer provided on the second reflecting mirror layer so as to cover the current confinement region, the semiconductor current diffusion layer having a stacked structure of first and second semiconductor current diffusion films, the first semiconductor current diffusion film being located nearer the semiconductor active layer than the second semiconductor current diffusion film, the first semiconductor current diffusion film being formed so as to have a greater thickness in a peripheral part located far from a center of the current confinement region as compared with a central part located near the center of the current confinement region, the second semiconductor current diffusion film having a higher carrier concentration than that of the peripheral part of the first semiconductor current diffusion film; and an electrode portion which injects a current into the semiconductor active layer, the electrode portion comprising a first electrode provided on the semiconductor current diffusion layer so as to surround the current confinement region and a second electrode provided on an opposite side of the substrate from the semiconductor active layer.