Fiber-optic communication systems require a light source to generate the signal that the fiber transmits. ar-ideal radiation source for fiber optical communications. Thus, LEDs are useful for relatively tringent reliability constraints present a special problem. Some inexpensive short-distance systems use LEDs that emit visible light, but most systems carry. Essential building blocks for fiber testing, offers optical light sources with multiple wavelength options for component testing, R&D, manufacturing and field environments. Optical light sources simulate the optical voice, video and data signals of real-life service applications, making them an. Semiconductor optical sources have the physical characteristics and performance properties necessary for successful implementations of fiber optic systems. It is desirable that optical sources: 6-2 •Be compatible in size to low-loss optical fibers by having a small light-emitting area capable of.