A type of multi-step step-index, multimode optical fiber (MMF) manufactured of plastic rather than glass, POF has a large diameter core and a thin layer of cladding comprising multiple steps in index of refraction (IOR).The outside diameter of the fiber typically is approximately one millimeter (1.0 mm). The core is very large in diameter (960 microns), and the cladding only 40 microns or so. POF is designed to couple to a light-emitting diode (LED) emitting red light in the 650 nm window, which is in the visible light spectrum. In combination, the large mode field created by the large diameter core, the short wavelength of the signal, the use of LEDs as light sources, and the high IOR of the plastic relegate POF to short-haul, low-bandwidth applications. POF offers advantages in certain applications due to its flex strength, ability to withstand extremes of temperature (