US Patent 11693200 Double bonding when fabricating an optical device

Embodiments herein describe using a double wafer bonding process to form a photonic device. In one embodiment, during the bonding process, an optical element (e.g., a high precision optical element) is optically coupled to an optical device in an active surface layer. In one example, the optical element comprises a nitride layer which can be patterned to form a nitride waveguide, passive optical multiplexer or demultiplexer, or an optical coupler.