Designing Fiber Optic Systems

Lasers and LEDS Electrical to optical video converters generally have a BNC coaxial cable connector at the input and a fiber optic connector on the output. In order to get the digital bits down the fiber optic cable, a light emitting device is used, onto which the digital signal is modulated. Either a laser or an LED (Light Emitting Diode) is used for this purpose. Lasers are more expensive, but they have significant advantages over LEDs. Lasers concentrate the light into a narrow beam at a unique wavelength. This narrow beam can travel much further than the diverging light emitted from an LED. Even if distances are short, the additional signal strength offered by lasers gives the system designer many more options to employ patch panels, splitters and other devices. Multiple signals can also be carried over a single fiber by using lasers of different wavelengths. This is not possible with LEDs.