The optical-electrical interconnection device comprises a glass support member with front-end and back-end portions that define a plane and an aperture. A cantilever member extends from the back-end portion into the aperture. The cantilever member supports an interconnection optical waveguide. The cantilever member comprises a bend region that causes a front-end section of the cantilever member to extend out of the plane. The front-end section is flexible, which allows for the interconnection optical waveguide to be aligned and optically coupled to a device waveguide of an optical-electrical device. A photonic assembly is formed using the optical-electrical interconnection device and at least one optical-electrical device. Methods of forming optical and electrical interconnections using the optical-electrical interconnection device are also disclosed.