Abstract: A fabricating process may include: producing a trench, in an encapsulated-silicon layer, in the location where a silicon-nitride core of the waveguide must be produced; then depositing a silicon-nitride layer on the encapsulated-silicon layer, the thickness of the deposited silicon-nitride layer being sufficient to completely fill the trench; then removing the silicon nitride situated outside of the trench to uncover an upper face with which the trench filled with silicon nitride is flush; then depositing a dielectric layer that covers the uncovered upper face in order to finalize the encapsulation of the silicon-nitride core and thus to obtain a mixed layer containing both the silicon and silicon-nitride cores encapsulated in dielectric.

Abstract: A photonic chip including an optical coupler capable of transferring an optical signal between a first waveguide made of III-V material and a second waveguide made of silicon, this optical coupler including a first extension made of III-V material which extends the core of the first waveguide, a second extension made of silicon which extends the core of the second waveguide, and a SiGe inclusion buried inside of the second extension, this inclusion being made of SiGe whose chemical formula is Si1-xGex, where x is in the range between 0.2and 0.5, and being optically coupled, on a first side, to the first waveguide and, on a second opposite side, to the second waveguide.