Light emitting device

DETAILED DESCRIPTION It is therefore an object of the present invention to provide a high-reliability light emitting device by suppressing deterioration of an active layer resulting from diffusion of an introduced impurity.
According to a first aspect of the present invention, a light emitting device includes a layer having lattice mismatching provided between an active layer and a layer into which an impurity is introduced.
According to a second aspect of the present invention, an optical device includes a substrate, a first cladding layer formed on the substrate, an active layer formed on the first cladding layer, a non-doped second cladding layer formed on the active layer, a lattice-mismatched layer formed on the second cladding layer, and a doped third cladding layer formed on the lattice-mismatched layer.
According to the arrangement of the present invention, since the layer having the lattice mismatching is provided, the layer having the lattice mismatching suppresses diffusion of an introduced impurity.
Therefore, it is possible to suppress diffusion of the introduced impurity to an active layer beyond the layer having the lattice mismatching, and hence it is possible to suppress deterioration of the active layer and to consequently increase a lifetime of the light emitting device.