We show an assembly of plastic optical fluorescent fibers made by Optectron. A large number of colors can be obtained by the introduction of appropriated additives into the core of the fiber. These fluorescent POF are able to transform an ambient light into another light at wavelengths of longer wavelengths. The nominal output intensity of fluorescent fiber increases when the ambient light is increased, so these fluorescent POF are very sensitive to light and can be used for the detection and command of light. After examining the optical properties of fluorescent fibers, we describe some examples of applications in various domains.