An optical integrated device having an even height such that it can be easily arrayed or integrated with other devices in a single substrate. The device includes a semi-conductor substrate having a substrate-side electrode which is formed on one side of the semi-conductor substrate. A micro-lens layer is epitaxially grown on the opposite side to where the substrate-side electrode is formed. The opposite side also has a hemispherically etched surface. The device also includes epitaxial layers which are grown on a whole area on the micro lens layer and a dielectric film which is formed on the epitaxial layers. Additionally, an epilayer-side electrode is formed on a whole area of the dielectric film.