Techniques, systems, and devices are disclosed to provide multilayer platforms for integrating semiconductor integrated circuit dies, optical waveguides and photonic devices to provide intra-die or inter-die optical connectivity. For example, an integrated semiconductor device having integrated circuits respectively formed on different semiconductor integrated circuit dies is provided to include a carrier substrate structured to form openings on a top side of the carrier substrate; semiconductor integrated circuit dies fixed to bottom surfaces of the openings of the carrier substrate, each semiconductor integrated circuit die including a semiconductor substrate and an integrated circuit formed on the semiconductor substrate to include one or more circuit components, and each semiconductor integrated circuit die being structured to have a top surface substantially coplanar with the top side of the carrier substrate; and planar layers formed on top of the top surfaces of the semiconductor integrated circuit dies and the top side of the carrier substrate to include optical waveguides and photonic devices to provide (1) intra-die optical connectivity for photonic devices associated with a semiconductor integrated circuit die, or (2) inter-die optical connectivity for photonic devices associated with different semiconductor integrated circuit dies.