HETEROGENEOUSLY INTEGRATED ILLUMINATOR

A device comprises at least one of first, second and third elements fabricated on a common substrate. At least one of the first elements comprises an active waveguide structure and optical sources supporting an active optical mode and defined by at least one etch after attachment to the common substrate. At least one of the second elements comprises a passive waveguide structure supporting a passive optical mode, also comprising at least one of the one splitter structure and two emitter structures. At least one of the third elements, at least partly butt-coupled to at least one of the first elements, comprises an intermediate waveguide structure supporting intermediate optical modes. Mutual alignments of the first, second and third elements are defined using lithographic alignment marks that facilitate precise alignment between layers formed during processing steps of fabricating the first, the second and the third elements on a common substrate.