Abstract: Opto-isolators are disclosed which provide enhanced coupling between the light-emitting element and detector, and a method of manufacture is taught which permits efficient mass production of such devices. Recesses are etched in a silicon body and areas of the proper conductivity type are formed in the side walls to produce diodes, transistors or darlington pairs for light detection. Appropriate insulation and leads are then fabricated in the recesses to make contact to the detectors. In one embodiment, bonding pads are also formed at the bottom of the recesses along with associated conductors. Light emitting elements are then bonded to the pads on one major surface of the elements and wire bonded on the other major surfaces. The recesses are filled with an encapsulating material and the silicon body is etched apart to produce discrete devices.