Abstract: Disclosed is an optical coupler apparatus comprising a photo-emissive device and a photo-sensitive device responsive to the wavelengths emitted by the source. The devices are mounted on frame leads with their major faces opposed and spaced apart. The optical devices and a substantial portion of the supporting frame leads are then encapsulated in a molded body of substantially electrically non-conductive material which is substantially transparent to the operative wavelengths of the optical devices.The transparent material not only fills the space between the optical devices but also provides structural support for the leads. The transparent material is then covered with an opaque coating or an additional body of opaque material molded over the body of transparent material.