A device for generating an electrical signal that is a function of the optical power in an optical fiber. The device is comprised of a support substrate, a fused, bi-conically-tapered splitter-coupler, and a glass bead securing an optical fiber extending from the splitter-coupler to the substrate. An opening in the glass bead forms a gap in the optical fiber. A light-sensitive device is disposed in the opening to receive light traveling through the optical fiber from the splitter-coupler.