A backlight module including a frame, a reflective adhesive tape, a fixing adhesive tape, a reflective plate, a light-guiding plate and at least one of light source, is provided. The system comprises a substrate, an optical fiber disposed on the substrate so as to be outwardly curved, and an electrical conductor disposed over the outward curve of the optical fiber. The starting sol to be processed by a sol-gel method is a dispersion of fine alumina particles, fine aluminum hydroxide particles, fine silica particles or mixtures thereof.