Method for manufacturing a photonic chip comprising a first waveguide made of stoichiometric silicon nitride, a second waveguide made of crystalline semiconductor material and at least one active component which is optically coupled to the first waveguide via the second waveguide, this method comprising: - providing a substrate made of monocrystalline silicon on which a layer made of dielectric material is deposited, this substrate extending mainly in a plane called "plane of the substrate", then - vapour-phase depositing, on the layer made of dielectric material, a layer of stoichiometric silicon nitride followed by annealing at a temperature of between 1000°C and 1400°C, then - producing the first waveguide from this deposited and annealed layer of stoichiometric silicon nitride, then - encapsulating the first waveguide in a dielectric material in order to obtain an encapsulating layer in which the first waveguide is encapsulated, this encapsulating layer having an upper face on the side opposite the substrate, then - creating (126; 166) a layer made of crystalline semiconductor material directly on the upper face of the encapsulating layer, then - producing the second waveguide from this layer made of crystalline semiconductor material, this second waveguide being optically coupled to the waveguide by evanescent coupling, then - producing the active optical component, this active optical component being optically connected to the first waveguide via the second waveguide, then - producing power outlets in order to electrically connect the active optical component to a source of electrical energy, characterized in that creating (126; 166) the layer made of crystalline semiconductor material comprises the following operations: a) forming (128; 168) an aperture which passes through the encapsulating layer and opens into or onto the substrate, then b) epitaxially depositing (132; 172) a crystal nucleation material inside the aperture until this crystal nucleation material reaches the upper face and forms a seed crystal on this upper face, this crystal nucleation material having lattice parameters which are identical, to within plus or minus 50%, to those of the crystalline semiconductor material, then c) laterally epitaxially growing (136; 176) the same crystalline semiconductor material as that from which the second waveguide is produced from the seed crystal formed in order to form the layer made of crystalline semiconductor material from which the second waveguide is then produced. - providing a substrate made of monocrystalline silicon on which a layer made of dielectric material is deposited, this substrate extending mainly in a plane called "plane of the substrate", then - vapour-phase depositing, on the layer made of dielectric material, a layer of stoichiometric silicon nitride followed by annealing at a temperature of between 1000°C and 1400°C, then - producing the first waveguide from this deposited and annealed layer of stoichiometric silicon nitride, then - encapsulating the first waveguide in a dielectric material in order to obtain an encapsulating layer in which the first waveguide is encapsulated, this encapsulating layer having an upper face on the side opposite the substrate, then - creating (126; 166) a layer made of crystalline semiconductor material directly on the upper face of the encapsulating layer, then - producing the second waveguide from this layer made of crystalline semiconductor material, this second waveguide being optically coupled to the waveguide by evanescent coupling, then - producing the active optical component, this active optical component being optically connected to the first waveguide via the second waveguide, then - producing power outlets in order to electrically connect the active optical component to a source of electrical energy, a) forming (128; 168) an aperture which passes through the encapsulating layer and opens into or onto the substrate, then b) epitaxially depositing (132; 172) a crystal nucleation material inside the aperture until this crystal nucleation material reaches the upper face and forms a seed crystal on this upper face, this crystal nucleation material having lattice parameters which are identical, to within plus or minus 50%, to those of the crystalline semiconductor material, then c) laterally epitaxially growing (136; 176) the same crystalline semiconductor material as that from which the second waveguide is produced from the seed crystal formed in order to form the layer made of crystalline semiconductor material from which the second waveguide is then produced.