How to Determine the Bandwidth of Fiber Optic Cables

Fiber optic cables can transmit high amount of data over long distances more efficiently than other data-transmitting cables such as copper cables. Due to this property, fiber optic cables are used for networking in telecommunications, Internet and satellite television industries. 

Determining the Bandwidth

Fiber optic cables contain either one or multiple glass fibers that work as wavelengths to optical (lights) signals, virtually determining the bandwidth of fiber optic cables. Its characteristic benefit of immunity to chemicals, atmospheric or electricity interferences also determines its superiority. A ray of light that enters a fiber straight has a shorter path through the fiber than light that enters at an angle. This determines that different rays (modes) of light reach the end of fiber at different times limiting maximum frequency. Simply put, lesser the modes, higher the bandwidth.

The Myth of Limitless Bandwidth

Fiber optic cables generally boast of limitless bandwidth. Although this is not literally true, it is almost there. A typical optical fiber bandwidth can range from approximately 100 MHz/km using multi-mode fiber to over 1000 MHz/km using single-mode fibers. The 50/125 and 62.5/125 micron multi-mode cables are traditionally used in networks, whereas the 8.3/125 micron single mode cable is the latest and improved option.