Patent ID: 8315286

Claim:
A light emitting device comprising: a substrate formed of a single crystal having a zinc blende structure, and having a plane tilted at a predetermined angle from a low-index plane as a principal surface; a first cladding layer formed above the principal surface; an active layer formed above the first cladding layer; and a second cladding layer formed above the active layer, wherein the active layer includes a first side surface and a second side surface parallel to the first side surface, at least part of the active layer constitutes a first gain region and a second gain region, a reflectance of the first side surface is higher than a reflectance of the second side surface in a wavelength region of light generated in the first gain region and the second gain region, each of the first gain region and the second gain region is disposed from an end surface on the first side surface to an end surface on the second side surface, at least part of the end surface of the first gain region located on the first side surface and part of the end surface of the second gain region located on the first side surface overlap with each other, the end surface on the first side surface and the end surface on the second side surface fail to overlap with each other in a plan view from the first side surface side in each of the first gain region and the second gain region, a perpendicular of the first side surface is parallel to an off-direction of the substrate in a plan view, and a length of the first gain region and a length of the second gain region are equal to each other.