Abstract: A photonic integrated circuit that consists essentially of: a first die; and a second die that is bonded to the first die; wherein the first die includes a first silicon layer and an additional layer, a modulating electrode and a silicon nitride waveguide formed in the additional layer; and wherein the second die includes a patterned structure made of at least one electro-optical modulation material that is selected of lithium niobate, lithium titanate, barium titanate or graphene; wherein the patterned structure includes: an input region that is configured to receive radiation; a modulating region in which the radiation is modulated under a control of the modulating electrode to provide modulated radiation, and an output region that is optically coupled to the silicon nitride waveguide for providing the modulated radiation to the silicon nitride waveguide.