There is disclosed a variety of arrangements for tapping a portion of the signal power from an optical fiber waveguide without requiring that the fiber be terminated or broken. Power is coupled out of the fiber waveguide, which typically includes an inner core surrounded by a lower refractive index outer cladding, by disposing a dielectric body in a coupling relationship with an intermediate length of the fiber from which all or most of the cladding has been removed or, alternatively, which is bent to cause a portion of the power to radiate out of the inner core into the outer cladding of the fiber. The dielectric body couples power out of the fiber provided its index of refraction is approximately equal to, or greater than, that of the fiber cladding material. The power coupled out by the dielectric body is converted to a representative electrical signal by a photodetector disposed adjacent to the dielectric body.