Photonic integrated circuit and methods related to the photonic integrated circuit

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 comprises a first silicon layer and an additional layer, modulating electrodes formed in the additional layer;
• and
• wherein the second die comprises a silicon nitride waveguide and one or more patterned graphene structures;
• and
• wherein the one or more patterned graphene structures are configured to modulate, under a control of the modulating electrodes, radiation in the silicon nitride waveguide.

A method for operating a photonic integrated circuit, the method comprises:

• receiving optical signals by a silicon nitride waveguide that is optically coupled to a patterned structure made of an electro-optical modulation material that is selected of lithium niobate, lithium titanate or barium titanate;
• conveying the optical signals by the silicon nitride waveguide;
• modulating the optical signals, using one or more graphene structures to provide modulated optical signals;
• and
• conveying the modulated optical signals by the silicon nitride waveguide.