Patent ID: 7164157

Claim:
A light emitting device comprising a substrate transparent at the emission wavelength and an active layer structure formed on such substrate, in which a layer for suppressing spectral-intensity-modulation due to the substrate-mode is provided between said substrate and said active layer structure, and further comprising: a first-conduction-type clad layer having the same conduction type with said substrate and formed between said substrate and said active layer structure; and a first-conduction-type, low-refractive-index layer formed between said substrate and said first-conduction-type clad layer, wherein a relation expressed by the following inequality is satisfied: n sub >n clad1 >n LIL1 (inequality 1) where u sub represents the refractive index at the emission wavelength of said substrate, n clad1 represents the real part of an average refractive index at the emission wavelength of said first-conduction-type clad layer, and n LIL1 represents the average refractive index at the emission wavelength of said first-conduction-type, low-refractive-index layer.