A photonic circuit, comprising: - a first waveguide on a silicon substrate , said waveguide having a thickness of 1 - 12 μm and a refractive index of 3 - 3.5; - a second waveguide (52a-52c) having a thickness of 0.1 - 1 μm and a refractive index of 3.1 - 4, said waveguide having a tapered shape with a cross-section that is smaller at one end and larger at the opposite end at least in one direction; wherein the photonic circuit further comprises: - a photonic device comprising: - at least one layer of an optical material deposited on said first waveguide and arranged to optically interface with said second waveguide, wherein said optical material is one of graphene, germanium ora silicon-germanium alloy; - a layer of a dielectric material deposited on each layer of said optical material; said end of said tapered second waveguide having a smaller cross-section is interfaced with said first waveguide to provide adiabatic light transfer between said first and second waveguides, and wherein said photonic device is interfaced with said end (W3) of said second waveguide having a larger cross-section to provide optical coupling between said second waveguide and said photonic device, characterized in that said second waveguide (52a-52c) is deposited partly on said first waveguide and partly on the uppermost dielectric layer, and said second waveguide (52a - 52c) is a waveguide made of amorphous silicon or hydrogenated amorphous silicon. - a first waveguide on a silicon substrate , said waveguide having a thickness of 1 - 12 μm and a refractive index of 3 - 3.5; - a second waveguide (52a-52c) having a thickness of 0.1 - 1 μm and a refractive index of 3.1 - 4, said waveguide having a tapered shape with a cross-section that is smaller at one end and larger at the opposite end at least in one direction; - a photonic device comprising: - at least one layer of an optical material deposited on said first waveguide and arranged to optically interface with said second waveguide, wherein said optical material is one of graphene, germanium ora silicon-germanium alloy; - a layer of a dielectric material deposited on each layer of said optical material; said end of said tapered second waveguide having a smaller cross-section is interfaced with said first waveguide to provide adiabatic light transfer between said first and second waveguides, and wherein said photonic device is interfaced with said end (W3) of said second waveguide having a larger cross-section to provide optical coupling between said second waveguide and said photonic device, characterized in that said second waveguide (52a-52c) is deposited partly on said first waveguide and partly on the uppermost dielectric layer, and said second waveguide (52a - 52c) is a waveguide made of amorphous silicon or hydrogenated amorphous silicon. - at least one layer of an optical material deposited on said first waveguide and arranged to optically interface with said second waveguide, wherein said optical material is one of graphene, germanium ora silicon-germanium alloy; - a layer of a dielectric material deposited on each layer of said optical material; said end of said tapered second waveguide having a smaller cross-section is interfaced with said first waveguide to provide adiabatic light transfer between said first and second waveguides, and wherein said photonic device is interfaced with said end (W3) of said second waveguide having a larger cross-section to provide optical coupling between said second waveguide and said photonic device, characterized in that said second waveguide (52a-52c) is deposited partly on said first waveguide and partly on the uppermost dielectric layer, and said second waveguide (52a - 52c) is a waveguide made of amorphous silicon or hydrogenated amorphous silicon. <EOS>