A method for converting an optical signal, propagating in an optical fiber, into an electrical output signal, including the following steps: providing an optical interface having opposing flat surfaces and being formed of a material having a refractive index that is substantially higher than the refractive index of the optical fiber; disposing a first of the opposing flat surfaces of the interface adjacent an output end of the optical fiber, and disposing a photodetector adjacent a second of the opposing flat surfaces of the interface; whereby the optical signal is coupled into the photodetector and converted by the photodetector into an electrical output signal.