Edge emission type semiconductor device for emitting super luminescent light, its manufacture and spatial optical communication device

Abstract

A substrate has first and second edges disposed in parallel and a principal surface connecting the first and second edges. An active layer is formed on the principal surface. A ridge-like region is disposed on the active layer along a path interconnecting a point on the first edge and a point on the second edge. The ridge-like region is made of semiconductor material having a refraction index smaller than a refraction index of the active layer, and defines a waveguide. The path is disposed along the principal surface and includes a first region on the side of the first edge and a second region on the side of the second edge. A first angle is taken between a normal to the first edge directing toward the principal surface and the first region. A second angle smaller than the first angle is taken between a normal to the second edge directing toward the principal surface and the second region. Electrodes inject current in a region of the active layer along the path.