A semiconductor light emitting device includes a silicon substrate, a p-type semiconductor layer provided on the silicon substrate, a n-type semiconductor layer provided on the silicon substrate, the n-type semiconductor layer adjoining the p-type semiconductor layer, and a light emitting section formed at a p-n homojunction between the p-type semiconductor layer and the n-type semiconductor layer. The p-n homojunction is substantially perpendicular to a major surface of the silicon substrate. The p-n homojunction is corrugated with a period matched with an integer multiple of an emission wavelength at the light emitting section.