Optical integrated circuit with encapsulated edge coupler

An optical integrated circuit for edge coupling comprising:

• a substrate;
• a top layer arranged on the substrate comprising a waveguide;
• and
• an edge-coupler arranged on the substrate, the edge-coupler comprising an optical membrane extending above a cavity in the substrate and the edge-coupler being configured for optically coupling the waveguide to an external optical element;
• the optical integrated circuit being characterized in that it further comprises
• a mechanical support fixedly attached at an end thereof to the substrate, at least one of directly and indirectly via the top layer, and attached at an opposing end thereof to the optical membrane;
• wherein the mechanical support is fixedly attached, at least one of directly and indirectly to the substrate and to the optical membrane through at least one adhesive;
• wherein the at least one adhesive comprises an optical adhesive, wherein the optical adhesive is arranged in the cavity under the at least one optical membrane;
• wherein the edge coupler, the substrate the optical adhesive and the mechanical support jointly form a flat surface configured for edge coupling to the external optical element.